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Sample records for acrf millimeter wave

  1. The Status of the ACRF Millimeter Wave Cloud Radars (MMCRs), the Path Forward for Future MMCR Upgrades, the Concept of 3D Volume Imaging Radar and the UAV Radar

    SciTech Connect

    P Kollias; MA Miller; KB Widener; RT Marchand; TP Ackerman

    2005-12-30

    The United States (U.S.) Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) operates millimeter wavelength cloud radars (MMCRs) in several climatological regimes. The MMCRs, are the primary observing tool for quantifying the properties of nearly all radiatively important clouds over the ACRF sites. The first MMCR was installed at the ACRF Southern Great Plains (SGP) site nine years ago and its original design can be traced to the early 90s. Since then, several MMCRs have been deployed at the ACRF sites, while no significant hardware upgrades have been performed. Recently, a two-stage upgrade (first C-40 Digital Signal Processors [DSP]-based, and later the PC-Integrated Radar AcQuisition System [PIRAQ-III] digital receiver) of the MMCR signal-processing units was completed. Our future MMCR related goals are: 1) to have a cloud radar system that continues to have high reliability and uptime and 2) to suggest potential improvements that will address increased sensitivity needs, superior sampling and low cost maintenance of the MMCRs. The Traveling Wave Tube (TWT) technology, the frequency (35-GHz), the radio frequency (RF) layout, antenna, the calibration and radar control procedure and the environmental enclosure of the MMCR remain assets for our ability to detect the profile of hydrometeors at all heights in the troposphere at the ACRF sites.

  2. Millimeter Wave Ocular Effects

    DTIC Science & Technology

    1987-02-20

    illustrates the rabbit head in holder by photography (a), thermography (b) and thermographic profile (c). The temperature of the cornea was measured using an...and graphs of profiles of the 40 temperatures difference (final-initial) of the rabbit cornea heated by the focused beam of millimeter waves from the...antenna. 5. Cooling of the cornea by air flow. 43 6. Temperature as a function of power applied using 45 continuous wave millimeter waves of

  3. Communication at millimeter waves

    NASA Astrophysics Data System (ADS)

    Kamal, A. K.; Christopher, P. F.

    The advantage and disadvantages of millimeter waves for terrestrial and satellite communications are enumerated. Atmospheric attenuation is discussed in detail, with brief attention given to signal loss in particulates, sandstorms, snow, hail, and fog. Short closed forms are then found for gaseous attenuation on ground-satellite paths. An exponential rain loss probability density function is used in generating atmospheric loss at arbitrary required availability. It is pointed out that this loss (as a function of frequency) can be used to pick optimum carrier frequencies as a function of location, required availability, elevation angle, and system cost. An estimate is made of the rate-of-change of millimeter wave device availability. Special attention is given to GaAs FETs, not only because they will be useful, but because one phase of their millimeter wave performance is predictable: their noise performance as a function of frequency can be estimated with the aid of a Fukui equation.

  4. Millimeter Wave Antenna Technology,

    DTIC Science & Technology

    1984-09-30

    development work will be required. Milli- meter wave antennas play a key role in the rationale for millimeter system designs beas ihspatial resolution...results in their popularity for multiple bea applications. In their design, care ust be exercised to minimize reflection losses at the lens surfaces...Alternatively, the radome surface may be treated to repel the water, and rivulet flow results. Since the water is more randomly distribu- ted, the gain loss is

  5. Passive millimeter wave imaging

    NASA Astrophysics Data System (ADS)

    Pergande, Al; Dean, Donald D.; O'Donnell, Daniel J.

    1996-05-01

    Passive millimeter wave (MMW) imaging provides a breakthrough capability for driver vision enhancement to counter the blinding effects of inclement weather. This type of sensor images in a manner analogous to an infrared or visible camera, but receives its energy from the MMW portion of the electromagnetic spectrum. Technology has progressed to the point where MMW radiometric systems offer advantages to a number of vision applications. We report on our developmental 94 GHz radiometric testbed, and the eventual technological evolutions that will help MMW radiometers and radars meet military and commercial market needs.

  6. Millimeter Wave Vircator.

    DTIC Science & Technology

    1985-06-01

    blork number) The millimeter wave vircator has achieved a frequency in excess of 39.9 GHz and a peak power of the order of 21 kilowatts (fZ26.35 GHz ) for...achieved a frequency in excess of 39.9 GHz and a peak power of the order of 21 kilowatts (f>26.35 Gf.z) for a pulse duration of as short as 5 ns full...upon the experience of the NRL quasi-optical gyrotron ,2 we can make some reasonable estimates. Based upon an output power of 1MW, the 0 of the cavity

  7. Millimeter wave seeker technology

    NASA Astrophysics Data System (ADS)

    Clark, William H.

    1992-02-01

    A management overview of a new joint Navy/Army millimeter wave seeker technology development initiative is presented. The aim of this program is to provide advanced seeker components for endoatmospheric interceptors for strategic and theater missile defense. Development programs are outlined that address high output RF power utilizing solid state transmitters and integrated transmit/receive modules for potential employment with active electronically steered arrays. The hit to kill guidance issue is presented in terms of methods for achieving high angular tracking accuracy including adaptive boresight error compensation.

  8. Compressive passive millimeter wave imager

    DOEpatents

    Gopalsami, Nachappa; Liao, Shaolin; Elmer, Thomas W; Koehl, Eugene R; Heifetz, Alexander; Raptis, Apostolos C

    2015-01-27

    A compressive scanning approach for millimeter wave imaging and sensing. A Hadamard mask is positioned to receive millimeter waves from an object to be imaged. A subset of the full set of Hadamard acquisitions is sampled. The subset is used to reconstruct an image representing the object.

  9. Monolithic Millimeter Wave Oscillator

    NASA Astrophysics Data System (ADS)

    Wang, Nan-Lei

    There is an increasing interest in the millimeter -wave spectrum for use in communications and for military and scientific applications. The concept of monolithic integration aims to produce very-high-frequency circuits in a more reliable, reproducible way than conventional electronics, and also at lower cost, with smaller size and lighter weight. In this thesis, a negative resistance device is integrated monolithically with a resonator to produce an effective oscillator. This work fills the void resulting from the exclusion of the local oscillator from the monolithic millimeter-wave integrated circuit (MMMIC) receiver design. For convenience a microwave frequency model was used to design the resonator circuit. A 5 GHz hybrid oscillator was first fabricated to test the design; the necessary GaAs process technology was developed for the fabrication. Negative resistance devices and oscillator theory were studied, and a simple but practical model of the Gunn diode was devised to solve the impedance matching problem. Monolithic oscillators at the Ka band (35 GHz) were built and refined. All devices operated in CW mode. By means of an electric-field probe, the output power was coupled into a metallic waveguide for measurement purposes. The best result was 3.63 mW of power output, the highest efficiency was 0.43% and the frequency stability was better than 10-4. In the future, an IMPATT diode could replace the Gunn device to give much higher power and efficiency. A varactor-tuned circuit also suitable for large-scale integration is under study.

  10. Millimeter waves: acoustic and electromagnetic.

    PubMed

    Ziskin, Marvin C

    2013-01-01

    This article is the presentation I gave at the D'Arsonval Award Ceremony on June 14, 2011 at the Bioelectromagnetics Society Annual Meeting in Halifax, Nova Scotia. It summarizes my research activities in acoustic and electromagnetic millimeter waves over the past 47 years. My earliest research involved acoustic millimeter waves, with a special interest in diagnostic ultrasound imaging and its safety. For the last 21 years my research expanded to include electromagnetic millimeter waves, with a special interest in the mechanisms underlying millimeter wave therapy. Millimeter wave therapy has been widely used in the former Soviet Union with great reported success for many diseases, but is virtually unknown to Western physicians. I and the very capable members of my laboratory were able to demonstrate that the local exposure of skin to low intensity millimeter waves caused the release of endogenous opioids, and the transport of these agents by blood flow to all parts of the body resulted in pain relief and other beneficial effects.

  11. Millimeter Waves: Acoustic and Electromagnetic

    PubMed Central

    Ziskin, Marvin C.

    2012-01-01

    This article is the presentation I gave at the D'Arsonval Award Ceremony on June 14, 2011 at the Bioelectromagnetics Society Annual Meeting in Halifax, Nova Scotia. It summarizes my research activities in acoustic and electromagnetic millimeter waves over the past 47 years. My earliest research involved acoustic millimeter waves, with a special interest in diagnostic ultrasound imaging and its safety. For the last 21 years my research expanded to include electromagnetic millimeter waves, with a special interest in the mechanisms underlying millimeter wave therapy. Millimeter wave therapy has been widely used in the former Soviet Union with great reported success for many diseases, but is virtually unknown to Western physicians. I and the very capable members of my laboratory were able to demonstrate that the local exposure of skin to low intensity millimeter waves caused the release of endogenous opioids, and the transport of these agents by blood flow to all parts of the body resulted in pain relief and other beneficial effects. PMID:22926874

  12. Millimeter Wave Communication through Plasma

    NASA Technical Reports Server (NTRS)

    Bastin, Gary L.

    2008-01-01

    Millimeter wave communication through plasma at frequencies of 35 GHz or higher shows promise in maintaining communications connectivity during rocket launch and re-entry, critical events which are typically plagued with communication dropouts. Extensive prior research into plasmas has characterized the plasma frequency at these events, and research at the Kennedy Space Center is investigating the feasibility of millimeter communication through these plasma frequencies.

  13. Millimeter Wave Nonreciprocal Devices.

    DTIC Science & Technology

    1983-01-03

    gradients of the dc bias field saturation magnetization , or magnetic anisotrophy can control mode properties of magnetostatic waves (MSW) propagating in...measures microwave magnetic field patterns of magnetostatic waves in LPE- YIG thin films has been developed. The probe’s sensing element is either a... magnetic resonance mode of a YIG sphere. Theoretical analyses show that there is a critical ratio between the -4-Ai p. , , . , l!~ mj radius of the

  14. Millimeter wave polarimetric background measurements

    NASA Astrophysics Data System (ADS)

    Wallace, H. B.; McGee, R. A.

    1985-10-01

    Millimeter wave sensor research over the past years has been directed toward the development of a feature space for targets and background that is disjoint over a broad range of parameters. The results have been mixed at best. The BRL program is directed toward the investigation of the polarization and frequency characteristics of various types of background. The data would be collected so as to provide both systems engineers and systems analysts a useful and general set of millimeter wave background maps for development of performance estimates of current and proposed weapon systems. This paper highlights some of the key features of the instrumentation and measurement parameters which the authors believe to be important in establishing the polarization and frequency characteristics of both benign and hostile terrain backgrounds.

  15. Millimeter-wave active probe

    DOEpatents

    Majidi-Ahy, Gholamreza; Bloom, David M.

    1991-01-01

    A millimeter-wave active probe for use in injecting signals with frequencies above 50GHz to millimeter-wave and ultrafast devices and integrated circuits including a substrate upon which a frequency multiplier consisting of filter sections and impedance matching sections are fabricated in uniplanar transmission line format. A coaxial input and uniplanar 50 ohm transmission line couple an approximately 20 GHz input signal to a low pass filter which rolls off at approximately 25 GHz. An input impedance matching section couples the energy from the low pass filter to a pair of matched, antiparallel beam lead diodes. These diodes generate odd-numberd harmonics which are coupled out of the diodes by an output impedance matching network and bandpass filter which suppresses the fundamental and third harmonics and selects the fifth harmonic for presentation at an output.

  16. Advanced millimeter wave chemical sensor.

    SciTech Connect

    Gopalsami, N.

    1999-03-24

    This paper discusses the development of an advanced millimeter-wave (mm-wave) chemical sensor and its applications for environmental monitoring and arms control treaty verification. The purpose of this work is to investigate the use of fingerprint-type molecular rotational signatures in the mm-wave spectrum to sense airborne chemicals. The mm-wave spectrum to sense airborne chemicals. The mm-wave sensor, operating in the frequency range of 220-300 GHz, can work under all weather conditions and in smoky and dusty environments. The basic configuration of the mm-wave sensor is a monostatic swept-frequency radar consisting of a mm-wave sweeper, a hot-electron-bolometer or Schottky barrier detector, and a trihedral reflector. The chemical plume to be detected is situated between the transmitter/detector and the reflector. Millimeter-wave absorption spectra of chemicals in the plume are determined by measuring the swept-frequency radar return signals with and without the plume in the beam path. The problem of pressure broadening, which hampered open-path spectroscopy in the past, has been mitigated in this work by designing a fast sweeping source over a broad frequency range. The heart of the system is a Russian backward-wave oscillator (BWO) tube that can be tuned over 220-350 GHz. Using the Russian BWO tube, a mm-wave radar system was built and field-tested at the DOE Nevada Test Site at a standoff distance of 60 m. The mm-wave system detected chemical plumes very well; the detection sensitivity for polar molecules like methyl chloride was down to a concentration of 12 ppm.

  17. Frequency hopping millimeter wave reflectometer

    NASA Astrophysics Data System (ADS)

    Cupido, L.; Sánchez, J.; Estrada, T.

    2004-10-01

    Reflectometry techniques are employed to study density fluctuations in fusion plasmas either using one channel or two channels with slightly different frequencies, to probe simultaneously closely spaced plasma layers (for radial correlation studies). The present article describes a novel system with increasing measuring capability utilizing only one single frequency that can be hopped during the discharge. This broadband fast hopping mm-wave reflectometer (BFHR) has been developed for both ASDEX upgrade (Max Plank Institute-Garching-Germany) and TJ-II stellarator (CIEMAT-Spain). The BFHR incorporates frequency synthesizers at microwave frequencies multiplied into the millimeter-wave range and uses heterodyne detection for sensitive phase and amplitude measurements.

  18. Passive millimeter-wave imaging

    NASA Technical Reports Server (NTRS)

    Young, Stephen K.; Davidheiser, Roger A.; Hauss, Bruce; Lee, Paul S. C.; Mussetto, Michael; Shoucri, Merit M.; Yujiri, Larry

    1993-01-01

    Millimeter-wave hardware systems are being developed. Our approach begins with identifying and defining the applications. System requirements are then specified based on mission needs using our end-to-end performance model. The model was benchmarked against existing data bases and, where data is deficient, it is acquired via field measurements. The derived system requirements are then validated with the appropriate field measurements using our imaging testbeds and hardware breadboards. The result is a final system that satisfies all the requirements of the target mission.

  19. Research in millimeter wave techniques

    NASA Technical Reports Server (NTRS)

    Mcmillan, R. W.

    1987-01-01

    The areas of millimeter wave (MMW) research include atmospheric propagation and radiometry, advanced MMW component design with emphasis on quasi-optical techniques, and the development of MMW receivers, especially those using subharmonic mixers. Calculations of atmospheric attenuation and radiometric antenna temperature were made in the range 100 to 700 GHz, together with measurements of atmospheric antenna temperature near 95 and 183 GHz. Quasi-optical components designed include lenses, mirrors, and wire grid devices, as well as feedhorns for interference with waveguide components. Subharmonic mixers with state-of-the-art performance at 183 GHz were also developed. Each of these areas of research is summarized.

  20. Millimeter wave imaging: a historical review

    NASA Astrophysics Data System (ADS)

    Appleby, Roger; Robertson, Duncan A.; Wikner, David

    2017-05-01

    The SPIE Passive and Active Millimeter Wave Imaging conference has provided an annual focus and forum for practitioners in the field of millimeter wave imaging for the past two decades. To celebrate the conference's twentieth anniversary we present a historical review of the evolution of millimeter wave imaging over the past twenty years. Advances in device technology play a fundamental role in imaging capability whilst system architectures have also evolved. Imaging phenomenology continues to be a crucial topic underpinning the deployment of millimeter wave imaging in diverse applications such as security, remote sensing, non-destructive testing and synthetic vision.

  1. Millimeter and sub-millimeter wave detection of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Kolbe, W. F.; Leskovar, B.

    1987-08-01

    The measurement of small concentrations of hydrogen peroxide through the detection of rotational transitions in the millimeter and sub-millimeter wave regions is discussed. Calculated transition frequencies and absorption coefficients of H2O2 for frequencies up to 2000 GHz are presented. The reliability of the calculated values is illustrated by measurements of the linewidths and absorption coefficients of transitions in the 140 GHz range. Finally, methods for the detection of trace quantities of the peroxide molecule are briefly described.

  2. Topics in millimeter wave technology. Volume 1

    NASA Astrophysics Data System (ADS)

    Button, Kenneth John

    Topics dicussed include fin-line characteristics and circuits, millimeter-wave planar integrated-circuit filters, and H-plane millimeter-wave planar transmission lines and circuits. Attention is also given to modal power dynamics in multimode optical fibers and to a miniaturized monopulse assembly constructed in planar waveguide with multimode scalar horn feeds.

  3. Millimeter wave transmissometer computer system

    SciTech Connect

    Wiberg, J.D.; Widener, K.B.

    1990-04-01

    A millimeter wave transmissometer has been designed and built by the Pacific Northwest Laboratory in Richland, Washington for the US Army at the Dugway Proving Grounds in Dugway, Utah. This real-time data acquisition and control system is used to test and characterize battlefield obscurants according to the transmittance of electromagnetic radiation in the millimeter wavelengths. It is an advanced five-frequency instrumentation radar system consisting of a transceiver van and a receiver van deployed at opposite sides of a test grid. The transceiver computer systems is the successful integration of a Digital Equipment Corporation (DEC) VAX 8350, multiple VME bus systems with Motorola M68020 processors (one for each radar frequency), an IEEE-488 instrumentation bus, and an Aptec IOC-24 I/O computer. The software development platforms are the VAX 8350 and an IBM PC/AT. A variety of compilers, cross-assemblers, microcode assemblers, and linkers were employed to facilitate development of the system software. Transmittance measurements from each radar are taken forty times per second under control of a VME based M68020.

  4. Millimeter-wave compressive holography.

    PubMed

    Cull, Christy Fernandez; Wikner, David A; Mait, Joseph N; Mattheiss, Michael; Brady, David J

    2010-07-01

    We describe an active millimeter-wave holographic imaging system that uses compressive measurements for three-dimensional (3D) tomographic object estimation. Our system records a two-dimensional (2D) digitized Gabor hologram by translating a single pixel incoherent receiver. Two approaches for compressive measurement are undertaken: nonlinear inversion of a 2D Gabor hologram for 3D object estimation and nonlinear inversion of a randomly subsampled Gabor hologram for 3D object estimation. The object estimation algorithm minimizes a convex quadratic problem using total variation (TV) regularization for 3D object estimation. We compare object reconstructions using linear backpropagation and TV minimization, and we present simulated and experimental reconstructions from both compressive measurement strategies. In contrast with backpropagation, which estimates the 3D electromagnetic field, TV minimization estimates the 3D object that produces the field. Despite undersampling, range resolution is consistent with the extent of the 3D object band volume.

  5. Millimeter Wave Spectrum of Nitromethane

    NASA Astrophysics Data System (ADS)

    Ilyushin, V.

    2016-06-01

    A new study of the millimeter wave spectrum of nitromethane CH_3NO_2 is reported. The new measurements covering the frequency range from 49 GHz to 236 GHz have been carried out using spectrometer in IRA NASU (Ukraine). The transitions belonging to the m ≤ 8 torsional states have been analyzed using the RAM36 program, which has been modified for this study to take into account the quadrupole hyperfine structure due to presence of the nitrogen atom. The dataset consisting of 5838 microwave line frequencies and including transitions with J up to 50 was fit using a model consisting of 93 parameters and weighted root-mean-square deviation of 0.89 has been achieved. In the talk the details of this new study will be discussed. V. Ilyushin, Z. Kisiel, L. Pszczólkowski, H. Mäder, J. T. Hougen J. Mol. Spectrosc. 259 (2010) 26-38.

  6. Millimeter wave near-field study

    NASA Technical Reports Server (NTRS)

    Kefauver, Neill

    1990-01-01

    The possibility is evaluated of current technology measuring large aperture millimeter wave antennas. Included are a mathematical modeling of system errors, experimental data supporting error model, predictions of system accuracy at millimeter wavelengths, advantage of near-field measurements, and a cost estimate for a facility upgrade. The use is emphasized of software compensation and other inexpensive alternatives to develop a near optimum solution to near-field measurement problems at millimeter wavelengths.

  7. 3D-Printed Millimeter Wave Structures

    DTIC Science & Technology

    2016-03-14

    Wave Structures Andrew Zai, Michael Lis, Dave Cipolle, John Russo Maxwell Plaut, Theodore Fedynyshyn, and Jennifer Lewis* MIT Lincoln Laboratory...millimeter wave (mmW) components. The dielectric properties of the two materials are characterized at mmW frequencies and show properties comparable...millimeter wave components, filter, dielectric lens Introduction The trend to integrate microwave systems on one chip, such as with a monolithic

  8. Millimeter-wave sensor image enhancement

    NASA Technical Reports Server (NTRS)

    Wilson, William J.; Suess, Helmut

    1989-01-01

    Images from an airborne, scanning radiometer operating at a frequency of 98 GHz have been analyzed. The millimeter-wave images were obtained in 1985-1986 using the JPL millimeter-wave imaging sensor. The goal of this study was to enhance the information content of these images and make their interpretation easier. A visual-interpretative approach was used for information extraction from the images. This included application of nonlinear transform techniques for noise reduction and for color, contrast, and edge enhancement. Results of using the techniques on selected millimeter-wave images are discussed.

  9. Experimental millimeter-wave satellite communications system

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoshiaki; Shimada, Masaaki; Arimoto, Yoshinori; Shiomi, Tadashi; Kitazume, Susumu

    This paper describes an experimental system of millimeter-wave satellite communications via Japan's Engineering Test Satellite-VI (ETS-VI) and a plan of experiments. Two experimental missions are planned using ETS-VI millimeter-wave (43/38 GHz bands) transponder, considering the millimeter-wave characteristics such as large transmission capacity and possibility to construct a small earth station with a high gain antenna. They are a personal communication system and an inter-satellite communication system. Experimental system including the configuration and the fundamental functions of the onboard transponder and the outline of the experiments are presented.

  10. Passive Millimeter Wave Camera (PMMWC) at TRW

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Engineers at TRW, Redondo Beach, California, inspect the Passive Millimeter Wave Camera, a weather-piercing camera designed to see through fog, clouds, smoke and dust. Operating in the millimeter wave portion of the electromagnetic spectrum, the camera creates visual-like video images of objects, people, runways, obstacles and the horizon. A demonstration camera (shown in photo) has been completed and is scheduled for checkout tests and flight demonstration. Engineer (left) holds a compact, lightweight circuit board containing 40 complete radiometers, including antenna, monolithic millimeter wave integrated circuit (MMIC) receivers and signal processing and readout electronics that forms the basis for the camera's 1040-element focal plane array.

  11. Passive Millimeter Wave Camera (PMMWC) at TRW

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Engineers at TRW, Redondo Beach, California, inspect the Passive Millimeter Wave Camera, a weather-piercing camera designed to 'see' through fog, clouds, smoke and dust. Operating in the millimeter wave portion of the electromagnetic spectrum, the camera creates visual-like video images of objects, people, runways, obstacles and the horizon. A demonstration camera (shown in photo) has been completed and is scheduled for checkout tests and flight demonstration. Engineer (left) holds a compact, lightweight circuit board containing 40 complete radiometers, including antenna, monolithic millimeter wave integrated circuit (MMIC) receivers and signal processing and readout electronics that forms the basis for the camera's 1040-element focal plane array.

  12. High power millimeter wave source development program

    NASA Technical Reports Server (NTRS)

    George, T. V.

    1989-01-01

    High power millimeter wave sources for fusion program; ECH source development program strategy; and 1 MW, 140 GHz gyrotron experiment design philosophy are briefly outlined. This presentation is represented by viewgraphs only.

  13. Autonomous millimeter-wave radar guidance systems

    NASA Astrophysics Data System (ADS)

    Schweiker, Kevin S.

    1992-07-01

    Hercules Defense Electronics Systems, Incorporated has applied millimeter wave technologies to a variety of guidance and control problems. This presentation documents the development and integration of an autonomous millimeter wave seeker to the AGM-65(D) (Maverick) air- to-ground missile. The resulting system was successfully demonstrated to search a large area for potential targets, prioritize detections, and guide the missile to the target during recent free-flight tests.

  14. Architectures and Devices for Millimeter Wave Imaging

    DTIC Science & Technology

    2009-02-01

    Architectures and Devices for Millimeter Wave Imaging by David A. Wikner , Joseph N. Mait, and Mark Mirotznik ARL-TR-4733 February 2009...4733 February 2009 Architectures and Devices for Millimeter Wave Imaging David A. Wikner and Joseph N. Mait Sensors and Electron Devices...PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 6. AUTHOR(S) David A. Wikner , Joseph N. Mait, and Mark Mirotznik 5f. WORK UNIT NUMBER

  15. The Millimeter-Wave Bolometric Interferometer

    NASA Technical Reports Server (NTRS)

    Ali, S.; Ade, P. A. R.; Bock, J. J.; Novak, G.; Piccirillo, L.; Timbie, P.; Tucker, G. S.

    2004-01-01

    The Millimeter-wave Bolometric Interferometer (MBI) is a proposed ground-based instrument designed for a wide range of cosmological and astrophysical observations including studies of the polarization of the cosmic microwave background (CMB). MBI combines the advantages of two well-developed technologies - interferometers and bolometric detectors. Interferometers have many advantages over .filled-aperture telescopes and are particularly suitable for high resolution imaging. Cooled bolometers are the highest sensitivity detectors at millimeter and sub-millimeter wavelengths. The combination of these two technologies results in an instrument with both high sensitivity and high angular resolution.

  16. Millimeter-wave antenna system

    NASA Technical Reports Server (NTRS)

    Evans, J.; Gould, W. I., Jr.

    1973-01-01

    Parabolic reflectors fabricated from Carbon Fiber Reinforced Plastic (CFRP) composite material will not distort their shape by more than 3 percent of millimeter wavelength, despite large temperature differences on reflector surfaces. CFRP has zero thermal expansion. It is derived from charred polyacrylonitrite plastic filaments that are combined with epoxy resin.

  17. Millimeter wave transmission systems and related devices

    NASA Technical Reports Server (NTRS)

    Hebert, L. M.

    1984-01-01

    A survey was made of the state-of-the-art in millimeter (20 GHz to 300 GHz) wave transmission systems and related devices. The survey includes summaries of analytical studies and theoretical results that were obtained for various transmission line structures. This material was supplemented by further analysis where appropriate. The transmission line structures are evaluated in terms of electrical performance, ease of manufacture, usefulness for building other devices and compatibility with solid state devices. Descriptions of waveguide transmission lines which have commonly been used in the microwave frequency range are provided along with special attention given to the problems that these guides face when their use is extended into the millimeter wave range. Also, guides which have been introduced specifically to satisfy the requirements of millimeter wave transmission are discussed in detail.

  18. Advanced Microwave/Millimeter-Wave Imaging Technology

    NASA Astrophysics Data System (ADS)

    Shen, Zuowei; Yang, Lu; Luhmann, N. C., Jr.; Domier, C. W.; Ito, N.; Kogi, Y.; Liang, Y.; Mase, A.; Park, H.; Sakata, E.; Tsai, W.; Xia, Z. G.; Zhang, P.

    Millimeter wave technology advances have made possible active and passive millimeter wave imaging for a variety of applications including advanced plasma diagnostics, radio astronomy, atmospheric radiometry, concealed weapon detection, all-weather aircraft landing, contraband goods detection, harbor navigation/surveillance in fog, highway traffic monitoring in fog, helicopter and automotive collision avoidance in fog, and environmental remote sensing data associated with weather, pollution, soil moisture, oil spill detection, and monitoring of forest fires, to name but a few. The primary focus of this paper is on technology advances which have made possible advanced imaging and visualization of magnetohydrodynamic (MHD) fluctuations and microturbulence in fusion plasmas. Topics of particular emphasis include frequency selective surfaces, planar Schottky diode mixer arrays, electronically controlled beam shaping/steering arrays, and high power millimeter wave local oscillator and probe sources.

  19. Channel and collateral effect of millimeter-wave multiplicate spectrum

    NASA Astrophysics Data System (ADS)

    Dong, Shuyi; Tang, Li; Di, Wenyuan; Zhang, Dongguo; Li, Ning; Zhao, Yongjiu

    1998-11-01

    Combining with acupuncture and moxibustion theory of China, this paper discussed acupuncture and moxibustion effect of millimeter wave multiplied with infrared ray and bass spectrum, and provided a feasible path for applications of millimeter wave in biomedical engineering.

  20. Millimeter-Wave Cut-Off Switch.

    DTIC Science & Technology

    A millimeter-wave cut -off switch in a dielectric waveguide having a semi-insulating core and a semi-conducting epitaxial layer. A controller affixed...When the waveguide is properly dimensioned such that the operating frequency lies in the high-loss section near the cut -off frequency on the loss vs

  1. Millimeter-wave integrated circuit radiometers

    NASA Astrophysics Data System (ADS)

    Weinreb, Sander

    1997-06-01

    Millimeter-wave integrated circuits (MMICs) are briefly described and system configurations for millimeter-wave passive sensing utilizing MMIC's are reviewed in terms of the type of receiver (tuned RF or superheterodyne) and type of array (focal-plane or aperture). Data on the gain fluctuation which occurs in millimeter-wave field-effect transistors is presented along with an analysis of the effect of this fluctuation on radiometer sensitivity. Two MMIC remedies of this transistor gain fluctuation are then discussed. The first is the stabilization of the gain with a VHF pilot signal path built into a millimeter-wave MMIC low- noise amplifier; this MMIC has been designed, fabricated, and tested and system tests are expected later this year. The second remedy is a MMIC PIN diode switch which can be used as a Dicke load switch at the receiver input. The PIN switch, which also includes a thermal calibration method, can be chopped at a rapid rate (> 1 kHz) relative to the l/F spectrum of the transistor gain fluctuations so that sensitivity is not impaired. The layout and measured performance of a 80 to 100 GHz version of the switch is presented.

  2. Sub-millimeter wave frequency heterodyne detector system

    NASA Technical Reports Server (NTRS)

    Siegel, Peter H. (Inventor); Dengler, Robert (Inventor); Mueller, Eric R. (Inventor)

    2010-01-01

    The present invention relates to sub-millimeter wave frequency heterodyne imaging systems. More specifically, the present invention relates to a sub-millimeter wave frequency heterodyne detector system for imaging the magnitude and phase of transmitted power through or reflected power off of mechanically scanned samples at sub-millimeter wave frequencies.

  3. Sub-millimeter wave frequency heterodyne detector system

    NASA Technical Reports Server (NTRS)

    Siegel, Peter H. (Inventor); Dengler, Robert (Inventor); Mueller, Eric R. (Inventor)

    2009-01-01

    The present invention relates to sub-millimeter wave frequency heterodyne imaging systems. More specifically, the present invention relates to a sub-millimeter wave frequency heterodyne detector system for imaging the magnitude and phase of transmitted power through or reflected power off of mechanically scanned samples at sub-millimeter wave frequencies.

  4. Millimeter-wave beamrider and radar systems

    NASA Astrophysics Data System (ADS)

    McMillan, R. W.; Shackelford, R. G.; Gallagher, J. J.

    1981-02-01

    This paper discusses three brassboard millimeter wave systems which are being built for the Army by Georgia Tech. These systems are: (1) a 94 GHz coherent transmitter/receiver, (2) a 140 GHz incoherent transmitter/receiver, and (3) a 220 GHz radar. The first two systems are to be used primarily for evaluation of millimeter guidance techniques, and the third will be used to evaluate performance of a 220 GHz radar system in a tank-mounted, target acquisition application. All of the systems use extended interaction oscillator transmitters and Schottky-barrier mixer receivers, and the radar employs a unique quasi-optical duplexer, and an all solid-state receiver.

  5. MIMIC For Millimeter Wave Integrated Circuit Radars

    NASA Astrophysics Data System (ADS)

    Seashore, C. R.

    1987-09-01

    A significant program is currently underway in the U.S. to investigate, develop and produce a variety of GaAs analog circuits for use in microwave and millimeter wave sensors and systems. This represents a "new wave" of RF technology which promises to significantly change system engineering thinking relative to RF Architectures. At millimeter wave frequencies, we look forward to a relatively high level of critical component integration based on MESFET and HEMT device implementations. These designs will spawn more compact RF front ends with colocated antenna/transceiver functions and innovative packaging concepts which will survive and function in a typical military operational environment which includes challenging temperature, shock and special handling requirements.

  6. Millimeter Wave Dielectric Properties of Materials

    NASA Astrophysics Data System (ADS)

    Button, Kenneth J.; Afsar, M. N.

    1983-10-01

    Highly accurate continuous spectra of the absorption coefficient and refractive index of some potentially useful materials have been made over the 60-420 GHz range. Measurements have been made on some common ceramic, semiconductor, crystalline and glass materials. The absorption coefficient of low loss materials increases with frequency which implies that microwave data cannot be used for the design of millimeter wave dielectric waveguides, devices, windows and quasi-optical elements. The data in this paper show the millimeter wave frequency dependence of tan δ, the real and imaginary parts of the dielectric permittivity and the optical constants, namely, the refractive index and absorption coefficient. The measurements have been made in a plane-wave Michelson interferometer operating as a polarizing, dispersive Fourier transform spectrometer. The accuracy and reproducability of the refractive index is six significant figures.

  7. Considerations for millimeter wave printed antennas

    NASA Technical Reports Server (NTRS)

    Pozar, D. M.

    1983-01-01

    Calculated data are presented on the performance of printed antenna elements on substrates which may be electrically thick, as would be the case for printed antennas at millimeter wave frequencies. Printed dipoles and microstrip patch antennas on polytetrafluoroethylene (PTFE), quartz, and gallium arsenide substrates are considered. Data are given for resonant length, resonant resistance, bandwidth, loss due to surface waves, loss due to dielectric heating, and mutual coupling. Also presented is an optimization procedure for maximizing or minimizing power launched into surface waves from a multielement printed antenna array. The data are calculated by a moment method solution.

  8. Dielectric Measurements of Millimeter-Wave Materials

    NASA Astrophysics Data System (ADS)

    Afsar, M. N.

    1984-12-01

    It is no longer necessary to use extrapolated microwave dielectric data when designing millimeter-wave components, devices, and systems. Precision measurements can now be made to generate highly accurate millimeter-wave (5 to 1/2 mm) continuous spectra on complex refractive index, complex dielectric permittivity, and loss tangent for a variety of materials such as common ceramics, semiconductors, crystalline, and glassy materials. The continuous spectra reveal an increase in dielectric loss with increase in frequency in this wavelength range for most materials. Reliable measurements also reveal that the method of preparation of nominally identical specimens can change the dielectric losses by many factors. These broad-band measurements were carried out employing dispersive Fourier transform spectroscopy applied to a modular two-beam polarization interferometer. Data obtained with Fabry-Perot open resonator methods at wavelengths of 5 mm and longer will also be compared.

  9. Millimeter wave sensor for monitoring effluents

    DOEpatents

    Gopalsami, Nachappa; Bakhtiari, Sasan; Raptis, Apostolos C.; Dieckman, Stephen L.

    1995-01-01

    A millimeter-wave sensor for detecting and measuring effluents from processing plants either remotely or on-site includes a high frequency signal source for transmitting frequency-modulated continuous waves in the millimeter or submillimeter range with a wide sweep capability and a computer-controlled detector for detecting a plurality of species of effluents on a real time basis. A high resolution spectrum of an effluent, or effluents, is generated by a deconvolution of the measured spectra resulting in a narrowing of the line widths by 2 or 3 orders of magnitude as compared with the pressure broadened spectra detected at atmospheric pressure for improved spectral specificity and measurement sensitivity. The sensor is particularly adapted for remote monitoring such as where access is limited or sensor cost restricts multiple sensors as well as for large area monitoring under nearly all weather conditions.

  10. Millimeter and submillimeter wave antenna structure

    NASA Technical Reports Server (NTRS)

    Rebiez, Gabriel M. (Inventor); Rutledge, David B. (Inventor)

    1989-01-01

    An integrated circuit antenna structure for transmitting or receiving millimeter and/or submillimeter wave radiation having an antenna relatively unimpaired by the antenna mounting arrangment is disclosed herein. The antenna structure of the present invention includes a horn disposed on a substrate for focusing electromagnetic energy with respect to an antenna. The antenna is suspended relative to the horn to receive or transmit the electromagnetic energy focused thereby.

  11. Superconducting submillimeter and millimeter wave detectors

    SciTech Connect

    Nahum, M.

    1992-10-20

    The series of projects described in this dissertation was stimulated by the discovery of high temperature superconductivity. Our goal was to develop useful applications which would be competitive with the current state of technology. The high-[Tc] microbolometer was developed into the most sensitive direct detector of millimeter waves, when operated at liquid nitrogen temperatures. The thermal boundary resistance of thin YBa[sub 2]Cu[sub 3]0[sub 7-[delta

  12. Millimeter Wave Holographical Inspection of Honeycomb Composites

    NASA Technical Reports Server (NTRS)

    Case, J. T.; Kharkovsky, S.; Zoughi, R.; Stefes, G.; Hepburn, Frank L.; Hepburn, Frank L.

    2007-01-01

    Multi-layered composite structures manufactured with honeycomb, foam or balsa wood cores are finding increasing utility in a variety of aerospace, transportation, and infrastructure applications. Due to the low conductivity and inhomogeneity associated with these composites standard nondestructive testing (NDT) methods are not always capable of inspecting their interior for various defects caused during the manufacturing process or as a result of in-service loading. On the contrary, microwave and millimeter wave NDT methods are well-suited for inspecting these structures since signals at these frequencies readily penetrate through these structures and reflect from different interior boundaries revealing the presence of a wide range of defects such as disbond, delamination, moisture and oil intrusion, impact damage, etc. Millimeter wave frequency spectrum spans 30 GHz - 300 GHz with corresponding wavelengths of 10 - 1 mm. Due to the inherent short wavelengths at these frequencies, one can produce high spatial resolution images of these composites either using real-antenna focused or synthetic-aperture focused methods. In addition, incorporation of swept-frequency in the latter method (i.e., holography) results in high-resolution three-dimensional images. This paper presents the basic steps behind producing such images at millimeter wave frequencies and the results of two honeycomb composite panels are demonstrated at Q-band (33-50 GHz). In addition, these results are compared to previous results using X-ray computed tomography.

  13. Millimeter Wave Holographical Inspection of Honeycomb Composites

    NASA Astrophysics Data System (ADS)

    Case, J. T.; Kharkovsky, S.; Zoughi, R.; Steffes, G.; Hepburn, F. L.

    2008-02-01

    Multi-layered composite structures manufactured with honeycomb, foam, or balsa wood cores are finding increasing utility in a variety of aerospace, transportation, and infrastructure applications. Due to the low conductivity and inhomogeneity associated with these composites, standard nondestructive testing (NDT) methods are not always capable of inspecting their interior for various defects caused during the manufacturing process or as a result of in-service loading. On the contrary, microwave and millimeter wave NDT methods are well-suited for inspecting these structures since signals at these frequencies readily penetrate through these structures and reflect from different interior boundaries revealing the presence of a wide range of defects such as isband, delamination, moisture and oil intrusion, impact damage, etc. Millimeter wave frequency spectrum spans 30 GHz-300 GHz with corresponding wavelengths of 10-1 mm. Due to the inherent short wavelengths at these frequencies, one can produce high spatial resolution images of these composites either using real-antenna focused or synthetic-aperture focused methods. In addition, incorporation of swept-frequency in the latter method (i.e., holography) results in high-resolution three-dimensional images. This paper presents the basic steps behind producing such images at millimeter wave frequencies and the results of two honeycomb composite panels are demonstrated at Q-band (33-50 GHz). In addition, these results are compared to previous results using X-ray computed tomography.

  14. Millimeter-wave antenna design

    NASA Technical Reports Server (NTRS)

    Leighton, R. B.

    1977-01-01

    Problems and opportunities are discussed for adapting certain design features and construction techniques, developed for producing high accuracy ground based radio dishes, to producing milimeter wave dishes for space use. Specifically considered is a foldable telescope of 24 m aperture and 9.6 m focal length, composed of 37 rigid hexagonal panels, which will fit within the 4.5 m diameter x 18 m long payload limits of space shuttle. As here conceived, the telescope would be a free flyer with its own power and pointing systems. Some of the structural design features and construction procedures are considered.

  15. Millimeter wave satellite concepts, volume 1

    NASA Technical Reports Server (NTRS)

    Hilsen, N. B.; Holland, L. D.; Thomas, R. E.; Wallace, R. W.; Gallagher, J. G.

    1977-01-01

    The identification of technologies necessary for development of millimeter spectrum communication satellites was examined from a system point of view. Development of methodology based on the technical requirements of potential services that might be assigned to millimeter wave bands for identifying the viable and appropriate technologies for future NASA millimeter research and development programs, and testing of this methodology with selected user applications and services were the goals of the program. The entire communications network, both ground and space subsystems was studied. Cost, weight, and performance models for the subsystems, conceptual design for point-to-point and broadcast communications satellites, and analytic relationships between subsystem parameters and an overall link performance are discussed along with baseline conceptual systems, sensitivity studies, model adjustment analyses, identification of critical technologies and their risks, and brief research and development program scenarios for the technologies judged to be moderate or extensive risks. Identification of technologies for millimeter satellite communication systems, and assessment of the relative risks of these technologies, was accomplished through subsystem modeling and link optimization for both point-to-point and broadcast applications.

  16. Recent developments in millimeter-wave antennas

    NASA Astrophysics Data System (ADS)

    Ray, S.; Mittra, R.; Trinh, T.; Paleta, R.

    Several types of antennas for use at millimeter-wave frequencies are presented. The first is a leaky-wave structure consisting of a rectangular dielectric rod with metallic strips on one side. This structure radiates a fan-shaped beam in the near-broadside range and can be frequency scanned. A modification of this antenna is the horn-image guide antenna. This antenna consists of a leaky-wave structure, as described above, that is mounted in a metal trough. A metal flare is added along the trough for increased beamwidth control and directivity. This antenna produces a beam which is narrow in both planes and has substantially higher gain than the leaky-wave antenna alone. A particular advantage of both these types of antennas is their integrability with a dielectric waveguide integrated circuit.

  17. A millimeter-wave tunneladder TWT

    NASA Technical Reports Server (NTRS)

    Wilson, D.

    1988-01-01

    A millimeter-wave traveling wave tube (TWT) was developed using a dispersive, high-impedance forward wave interaction structure based on a ladder, with non-space-harmonic interaction, for a tube with high gain per inch and high efficiency. The 'TunneLadder' interaction structure combines ladder properties modified to accommodate Pierce gun beam optics in a radially magnetized PM focusing structure. The development involved the fabrication of chemically milled, shaped ladders diffusion brazed to diamond cubes which are in turn active diffusion brazed to each ridge of a doubly ridged waveguide. Cold-test data, representing the (omega)(beta) and and impedance characteristics of the modified ladder circuit, were used in small and large-signal computer programs to predict TWT gain and efficiency. The structural design emphasizes ruggedness and reliability. Actual data from tested tubes verify the predicted performance while providing broader bandwidth than expected.

  18. Microbolometer Detectors for Passive Millimeter-Wave Imaging

    DTIC Science & Technology

    2005-03-01

    Proc. SPIE April 2003, 5077, 33–41. 6. Rahman A.; et al. Micromachined room - temperature microbolometer for mm-wave detection and focal-plane... Microbolometer Detectors for Passive Millimeter -Wave Imaging by Joseph Nemarich ARL-TR-3460 March 2005...GRANT NUMBER 4. TITLE AND SUBTITLE Microbolometer Detectors for Passive Millimeter -Wave Imaging 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER

  19. Personnel and mail screening with millimeter waves

    NASA Astrophysics Data System (ADS)

    McMakin, Douglas L.; Sheen, David M.; Griffin, Jeffery W.; Valentine, Nancy B.; Lechelt, Wayne M.

    2005-05-01

    The detection and interdiction of biological and chemical warfare agents at point-of-entry military, government, and civilian facilities remains a high priority for security personnel. Commercial personnel and mail screening technologies for these harmful agents are still being developed and improved upon to meet all security client requirements. Millimeter-wave holographic imaging technology developed at the Pacific Northwest National Laboratory is an ideal sensor to interrogate objects concealed behind low dielectric barriers such as paper, cardboard, and clothing. It uses harmless millimeter waves to illuminate the object or person under surveillance. The waves penetrate through the low dielectric barrier and either reflects off or pass through the hidden object, depending on its material dielectric properties. The reflected signals are digitized and sent to high-speed computers to form high-resolution, three-dimensional (3-D) images. Feasibility imaging studies have been conducted to determine whether simulated biological or chemical agents concealed in mail packages or under clothing could be detected using holographic radar imaging techniques. The results of this study will be presented in this paper.

  20. The Millimeter-Wave Imaging Radiometer (MIR)

    NASA Technical Reports Server (NTRS)

    Gasiewski, A. J.; Jackson, D. M.; Adler, R. F.; Dod, L. R.; Shiue, J. C.

    1991-01-01

    The Millimeter-Wave Imaging Radiometer (MIR) is a new instrument being designed for studies of airborne passive microwave retrieval of tropospheric water vapor, clouds, and precipitation parameters. The MIR is a total-power cross-track scanning radiometer for use on either the NASA ER-2 (high-altitude) or DC-8 (medium altitude) aircraft. The current design includes millimeter-wave (MMW) channels at 90, 166, 183 +/- 1,3,7, and 220 GHz. An upgrade for the addition of submillimeter-wave (SMMW) channels at 325 +/- 1,3,7 and 340 GHz is planned. The nadiral spatial resolution is approximately 700 meters at mid-altitude when operated aboard the NASA ER-2. The MIR consists of a scanhead and data acquisition system, designed for installation in the ER-2 superpod nose cone. The scanhead will house the receivers (feedhorns, mixers, local oscillators, and preamplifiers), a scanning mirror, hot and cold calibration loads, and temperature sensors. Particular attention is being given to the characterization of the hot and cold calibration loads through both laboratory bistatic scattering measurements and analytical modeling. Other aspects of the MIR and the data acquisition system are briefly discussed, and diagrams of the location of the MIR in the ER-2 superpod nosecone and of the data acquisition system are presented.

  1. Apparatus for millimeter-wave signal generation

    DOEpatents

    Vawter, G. Allen; Hietala, Vincent M.; Zolper, John C.; Mar, Alan; Hohimer, John P.

    1999-01-01

    An opto-electronic integrated circuit (OEIC) apparatus is disclosed for generating an electrical signal at a frequency .gtoreq.10 GHz. The apparatus, formed on a single substrate, includes a semiconductor ring laser for generating a continuous train of mode-locked lasing pulses and a high-speed photodetector for detecting the train of lasing pulses and generating the electrical signal therefrom. Embodiments of the invention are disclosed with an active waveguide amplifier coupling the semiconductor ring laser and the high-speed photodetector. The invention has applications for use in OEICs and millimeter-wave monolithic integrated circuits (MMICs).

  2. Millimeter wave passive components for polarization measurements

    NASA Astrophysics Data System (ADS)

    Peverini, O. A.; Baralis, M.; Tascone, R.; Trinchero, D.; Olivieri, A.; Carretti, E.; Cortiglioni, S.

    2002-03-01

    The Stokes parameters of the polarized sky emission are detected by a correlation unit called Hybrid Phase Discriminator (HPD), which uses signals obtained by an Ortho-mode Transducer (OMT). In the millimeter wave range and for rather large bandwidths, heterodyne receivers are not applicable, and the correlation units have to work at the frequency of the radiometer. This contribution deals with a Ka-band prototype of a new configuration of waveguide HPD, which presents a high degree of sensitivity for the detection of linearly polarized radiation. .

  3. Full spectrum millimeter-wave modulation.

    PubMed

    Macario, Julien; Yao, Peng; Shi, Shouyuan; Zablocki, Alicia; Harrity, Charles; Martin, Richard D; Schuetz, Christopher A; Prather, Dennis W

    2012-10-08

    In recent years, the development of new lithium niobate electro-optic modulator designs and material processing techniques have contributed to support the increasing need for faster optical networks by considerably extending the operational bandwidth of modulators. In an effort to provide higher bandwidths for future generations of networks, we have developed a lithium niobate electro-optic phase modulator based on a coplanar waveguide ridged structure that operates up to 300 GHz. By thinning the lithium niobate substrate down to less than 39 µm, we are able to eliminate substrate modes and observe optical sidebands over the full millimeter-wave spectrum.

  4. High resolution millimeter-wave imaging sensor

    NASA Technical Reports Server (NTRS)

    Wilson, W. J.; Howard, R. J.; Parks, G. S.

    1985-01-01

    A scanning 3-mm radiometer is described that has been built for use on a small aircraft to produce real time high resolution images of the ground when atmospheric conditions such as smoke, dust, and clouds make IR and visual sensors unusable. The sensor can be used for a variety of remote sensing applications such as measurements of snow cover and snow water equivalent, precipitation mapping, vegetation type and extent, surface moisture and temperature, and surface thermal inertia. The advantages of millimeter waves for cloud penetration and the ability to observe different physical phenomena make this system an attractive supplement to visible and IR remote sensing systems.

  5. Millimeter wave dosimetry of human skin.

    PubMed

    Alekseev, S I; Radzievsky, A A; Logani, M K; Ziskin, M C

    2008-01-01

    To identify the mechanisms of biological effects of mm waves it is important to develop accurate methods for evaluating absorption and penetration depth of mm waves in the epidermis and dermis. The main characteristics of mm wave skin dosimetry were calculated using a homogeneous unilayer model and two multilayer models of skin. These characteristics included reflection, power density (PD), penetration depth (delta), and specific absorption rate (SAR). The parameters of the models were found from fitting the models to the experimental data obtained from measurements of mm wave reflection from human skin. The forearm and palm data were used to model the skin with thin and thick stratum corneum (SC), respectively. The thin SC produced little influence on the interaction of mm waves with skin. On the contrary, the thick SC in the palm played the role of a matching layer and significantly reduced reflection. In addition, the palmar skin manifested a broad peak in reflection within the 83-277 GHz range. The viable epidermis plus dermis, containing a large amount of free water, greatly attenuated mm wave energy. Therefore, the deeper fat layer had little effect on the PD and SAR profiles. We observed the appearance of a moderate SAR peak in the therapeutic frequency range (42-62 GHz) within the skin at a depth of 0.3-0.4 mm. Millimeter waves penetrate into the human skin deep enough (delta = 0.65 mm at 42 GHz) to affect most skin structures located in the epidermis and dermis.

  6. Universal Millimeter-Wave Radar Front End

    NASA Technical Reports Server (NTRS)

    Perez, Raul M.

    2010-01-01

    A quasi-optical front end allows any arbitrary polarization to be transmitted by controlling the timing, amplitude, and phase of the two input ports. The front end consists of two independent channels horizontal and vertical. Each channel has two ports transmit and receive. The transmit signal is linearly polarized so as to pass through a periodic wire grid. It is then propagated through a ferrite Faraday rotator, which rotates the polarization state 45deg. The received signal is propagated through the Faraday rotator in the opposite direction, undergoing a further 45 of polarization rotation due to the non-reciprocal action of the ferrite under magnetic bias. The received signal is now polarized at 90deg relative to the transmit signal. This signal is now reflected from the wire grid and propagated to the receive port. The horizontal and vertical channels are propagated through, or reflected from, another wire grid. This design is an improvement on the state of the art in that any transmit signal polarization can be chosen in whatever sequence desired. Prior systems require switching of the transmit signal from the amplifier, either mechanically or by using high-power millimeter-wave switches. This design can have higher reliability, lower mass, and more flexibility than mechanical switching systems, as well as higher reliability and lower losses than systems using high-power millimeter-wave switches.

  7. Novel Techniques for Millimeter-Wave Packages

    NASA Technical Reports Server (NTRS)

    Herman, Martin I.; Lee, Karen A.; Kolawa, Elzbieta A.; Lowry, Lynn E.; Tulintseff, Ann N.

    1995-01-01

    A new millimeter-wave package architecture with supporting electrical, mechanical and material science experiment and analysis is presented. This package is well suited for discrete devices, monolithic microwave integrated circuits (MMIC's) and multichip module (MCM) applications. It has low-loss wide-band RF transitions which are necessary to overcome manufacturing tolerances leading to lower per unit cost Potential applications of this new packaging architecture which go beyond the standard requirements of device protection include integration of antennas, compatibility to photonic networks and direct transitions to waveguide systems. Techniques for electromagnetic analysis, thermal control and hermetic sealing were explored. Three dimensional electromagnetic analysis was performed using a finite difference time-domain (FDTD) algorithm and experimentally verified for millimeter-wave package input and output transitions. New multi-material system concepts (AlN, Cu, and diamond thin films) which allow excellent surface finishes to be achieved with enhanced thermal management have been investigated. A new approach utilizing block copolymer coatings was employed to hermetically seal packages which met MIL STD-883.

  8. Novel Techniques for Millimeter-Wave Packages

    NASA Technical Reports Server (NTRS)

    Herman, Martin I.; Lee, Karen A.; Kolawa, Elzbieta A.; Lowry, Lynn E.; Tulintseff, Ann N.

    1995-01-01

    A new millimeter-wave package architecture with supporting electrical, mechanical and material science experiment and analysis is presented. This package is well suited for discrete devices, monolithic microwave integrated circuits (MMIC's) and multichip module (MCM) applications. It has low-loss wide-band RF transitions which are necessary to overcome manufacturing tolerances leading to lower per unit cost Potential applications of this new packaging architecture which go beyond the standard requirements of device protection include integration of antennas, compatibility to photonic networks and direct transitions to waveguide systems. Techniques for electromagnetic analysis, thermal control and hermetic sealing were explored. Three dimensional electromagnetic analysis was performed using a finite difference time-domain (FDTD) algorithm and experimentally verified for millimeter-wave package input and output transitions. New multi-material system concepts (AlN, Cu, and diamond thin films) which allow excellent surface finishes to be achieved with enhanced thermal management have been investigated. A new approach utilizing block copolymer coatings was employed to hermetically seal packages which met MIL STD-883.

  9. Millimeter Wave Rheometry: Theory and Experiment

    SciTech Connect

    Chun, Jaehun; McCloy, John S.; Crum, J. V.; Sundaram, S. K.

    2011-01-29

    A novel millimeter wave (MMW) rheometry is developed to determine the viscosity of fluid based on an unsteady film flow in an inclined plane. The method measures fringes due to MMW interference between the front and back surfaces of the fluid flowing across the field of view of a ceramic wave guide coupled to a MMW receiver. With knowledge of the dielectric constant, the interference fringe spacing is used to calculate the thickness of the fluid layer. This thickness is then transformed into the viscosity by means of a simple hydrodynamic theory. Our results show that the MMW rheometry can easily distinguish between the 30, 100, and 200 Pa•s silicone oils. The geometry of the method allows for potential industrial applications such as measuring viscosity of the flowing slag in slagging coal gasifiers. The MMW rheometry with simple modifications can be easily extended to measure important non-Newtonian fluid characteristics such as yield stress.

  10. Millimeter wave I-Q standoff biosensor

    NASA Astrophysics Data System (ADS)

    Liao, Shaolin; Bakhtiari, Sasan; Elmer, Thomas; Raptis, Apostolos C.; Mikhelson, Ilya V.; Sahakian, Alan V.

    2012-06-01

    A continuous wave (CW) 94-GHz millimeter wave (mmW) standoff biosensor has been developed for remote biometric sensing applications. The sensor measures the demodulated in-phase (I) and quadrature-phase (Q) components of the received reflected mmW signal from a subject. Both amplitude and phase of the reflected signal are obtained from downconverted I and Q channels from the quadrature mixer. The mmW sensor can faithfully monitor human vital signs (heartbeat and respiration) at relatively long standoff distances. Principle Component Analysis (PCA) is used to extract the heartbeat, the respiration and the body motion signals. The approach allows one to deduce information about amplitude and beat-to-beat rate of the respiration and the heartbeat. Experimental results collected from a subject were analyzed and compared to the signal obtained with a three-electrode ECG monitoring instrument.

  11. Integrated design and simulation for millimeter-wave antenna systems

    NASA Technical Reports Server (NTRS)

    Cwik, T.; Katz, D. S.; Villegas, F. J.

    2000-01-01

    In this paper the development and application of MODTool (Millimeter-wave Optics Design), a design tool that efficiently integrates existing millimeter-wave optics design software with a solid body modeler and thermal/structural analysis packages, will be discussed.

  12. Integrated design and simulation for millimeter-wave antenna systems

    NASA Technical Reports Server (NTRS)

    Cwik, T.; Katz, D. S.; Villegas, F. J.

    2000-01-01

    In this paper the development and application of MODTool (Millimeter-wave Optics Design), a design tool that efficiently integrates existing millimeter-wave optics design software with a solid body modeler and thermal/structural analysis packages, will be discussed.

  13. Solid-State Millimeter-Wave Source Study: A Study of Two Novel Concepts for Generation of CW Millimeter Waves.

    DTIC Science & Technology

    1981-09-01

    AD-AI13 460 ROCKWELL INTERNATIONJAL DOWNEY CA SATEL ITE SYSTEMS DIV F/6 9/ SOLID-STATE MILLIMETER-WAVE SOURCE STUDY : A STUDY OF TWO NOVEL -- ETC(U...NA[ B11RIA ~ H ,A DR’ ’. 7.4 C79-606.12/501 SOLID-STATE MILLIMETER-WAVE SOURCE STUDY : A STUDY OF TWO NOVEL CONCEPTS FOR GENERATION OF CW MILLIMETER...ACCESSION NO, IENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Solid State Millimeter-Wave Source Study : A Study Final

  14. PNNL Expert Doug McMakin Discusses Millimeter Wave Technology

    SciTech Connect

    Doug McMakin

    2011-10-01

    Electrical Engineer Doug McMakin discusses Millimeter Wave Holographic technology, which uses non-harmful, ultrahigh-frequency radio waves to penetrate clothing to detect and identify concealed objects, as well as obtain accurate body measurements.

  15. PNNL Expert Doug McMakin Discusses Millimeter Wave Technology

    ScienceCinema

    Doug McMakin

    2016-07-12

    Electrical Engineer Doug McMakin discusses Millimeter Wave Holographic technology, which uses non-harmful, ultrahigh-frequency radio waves to penetrate clothing to detect and identify concealed objects, as well as obtain accurate body measurements.

  16. The millimeter-wave bolometric interferometer

    NASA Astrophysics Data System (ADS)

    Korotkov, Andrei L.; Kim, Jaiseung; Tucker, Gregory S.; Gault, Amanda; Hyland, Peter; Malu, Siddharth; Timbie, Peter T.; Bunn, Emory F.; Bierman, Evan; Keating, Brian; Murphy, Anthony; O'Sullivan, Créidhe; Ade, Peter A. R.; Calderon, Carolina; Piccirillo, Lucio

    2006-06-01

    The Millimeter-Wave Bolometric Interferometer (MBI) is designed for sensitive measurements of the polarization of the cosmic microwave background (CMB). MBI combines the differencing capabilities of an interferometer with the high sensitivity of bolometers at millimeter wavelengths. It views the sky directly through corrugated horn antennas with low sidelobes and nearly symmetric beam patterns to avoid spurious instrumental polarization from reflective optics. The design of the first version of the instrument with four 7-degree-FOV corrugated horns (MBI-4) is discussed. The MBI-4 optical band is defined by filters with a central frequency of 90 GHz. The set of baselines determined by the antenna separation makes the instrument sensitive to CMB polarization fluctuations over the multipole range l=150-270. In MBI-4, the signals from antennas are combined with a Fizeau beam combiner and interference fringes are detected by an array of spider-web bolometers with NTD germanium thermistors. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. Observations are planned from the Pine Bluff Observatory outside Madison, WI.

  17. The millimeter-wave bolometric interferometer (MBI)

    NASA Astrophysics Data System (ADS)

    Tucker, Gregory S.; Korotkov, Andrei L.; Gault, Amanda C.; Hyland, Peter O.; Malu, Siddharth; Timbie, Peter T.; Bunn, Emory F.; Keating, Brian G.; Bierman, Evan; O'Sullivan, Créidhe; Ade, Peter A. R.; Piccirillo, Lucio

    2008-07-01

    We report on the design and tests of a prototype of the Millimeter-wave Bolometric Interferometer (MBI). MBI is designed to make sensitive measurements of the polarization of the cosmic microwave background (CMB). It combines the differencing capabilities of an interferometer with the high sensitivity of bolometers at millimeter wavelengths. The prototype, which we call MBI-4, views the sky directly through four corrugated horn antennas. MBI ultimately will have ~ 1000 antennas. These antennas have low sidelobes and nearly symmetric beam patterns, so spurious instrumental polarization from reflective optics is avoided. The MBI-4 optical band is defined by filters with a central frequency of 90 GHz. The set of baselines, determined by placement of the four antennas, results in sensitivity to CMB polarization fluctuations over the multipole range l = 150 - 270. The signals are combined with a Fizeau beam combiner and interference fringes are detected by an array of spider-web bolometers. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. Initial tests and observations have been made at Pine Bluff Observatory (PBO) outside Madison, WI.

  18. The Millimeter-wave Bolometric Interferometer (MBI)

    NASA Astrophysics Data System (ADS)

    Gault, Amanda C.; Ade, P. A. R.; Bierman, E.; Bunn, E. F.; Hyland, P. O.; Keating, B. G.; Korotkov, A. L.; Malu, S. S.; O'Sullivan, C.; Piccirillo, L.; Timbie, P. T.; Tucker, G. S.

    2009-01-01

    We report on the design and tests of a prototype of the Millimeter-wave Bolometric Interferometer (MBI). MBI is designed to make sensitive measurements of the polarization of the cosmic microwave background (CMB). It combines the differencing capabilities of an interferometer with the high sensitivity of bolometers at millimeter wavelengths. The prototype, which we call MBI-4, views the sky directly through four corrugated horn antennas. MBI ultimately will have 1000 antennas. These antennas have low sidelobes and nearly symmetric beam patterns, so spurious instrumental polarization from reflective optics is avoided. The MBI-4 optical band is defined by filters with a central frequency of 90 GHz. The set of baselines, determined by placement of the four antennas, results in sensitivity to CMB polarization fluctuations over the multipole range l = 150 - 270. The signals are combined with a Fizeau beam combiner and interference fringes are detected by an array of spiderweb bolometers. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. Initial tests and observations have been made at Pine Bluff Observatory (PBO) outside Madison, WI. This work was supported by NASA grants NAG5-12758, NNX07AG82G, the Rhode Island Space Grant and the Wisconsin Space Grant.

  19. Microfabricated Millimeter-Wave High-Power Vacuum Electronic Amplifiers

    DTIC Science & Technology

    2015-01-01

    Research Laboratory is demonstrating and developing millimeter-wave vacuum electronic traveling wave tube amplifiers at W- and G-band in the 10’s to 100...much promise for fabricating millimeter-wave (mmW) and sub- mmW amplifiers [1-2]. Trends toward higher frequencies come at the expense of more...demonstrated that allow extremely high aspect ratio beam tunnels to be fabricated along with the all-copper slow-wave amplifier circuits (Patent

  20. Millimeter wave band ultra wideband transmitter MMIC

    NASA Astrophysics Data System (ADS)

    Ling, Jin; Rolland, Nathalie

    2015-09-01

    This paper presents a new millimeter-wave (MMW) ultra wideband (UWB) transmitter MMIC which has been developed in an OMMIC 0.1 μm GaAs PHEMT foundry process (ft = 100 GHz) for 22-29 GHz vehicular radar systems. The transmitter is composed of an MMW negative resistance oscillator (NRO), a power amplifier (PA), and two UWB pulse generators (PGs). In order to convert the UWB pulse signal to MMW frequency and reduce the total power consumption, the MMW NRO is driven by one of the UWB pulse generators and the power amplifier is triggered by another UWB pulse generator. The main advantages of this transmitter are: new design, simple architecture, high-precision distance measurements, infinite ON/OFF switch ratio, and low power consumption. The total power consumption of the transmitter MMIC is 218 mW with a peak output power of 5.5 dBm at 27 GHz.

  1. Passive millimeter-wave concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Sinclair, Gordon N.; Anderton, Rupert N.; Appleby, Roger

    2001-02-01

    A method of detecting weapons concealed under clothing using passive millimeter wave imaging is described. The optical properties of clothing are discussed and examples given of the spectral reflectivity and transmission. The transmission tends to be constant from 60 to 150 GHz above which it decreases for some clothing materials. The transmission of a cotton T-shirt is typically 95% and of a leather jacket up to 85% at lower frequencies. A model is presented for calculating the contrast of a metallic concealed weapon when hidden under clothing and it indicates contrasts as large as 200 K can be realized outdoors. The advantages of real time over static frame imagery are discussed. It is concluded that real time imagery offers considerable advantages as weapons can be very varied in size, position and orientation and movement offers vital clues to the human observer which aid the recognition process.

  2. Millimeter-Wave Atmospheric Sounder (MAS)

    NASA Technical Reports Server (NTRS)

    Hartmann, G. K.

    1988-01-01

    MAS is a remote sensing instrument for passive sounding (limb sounding) of the earth's atmosphere from the Space Shuttle. The main objective of the MAS is to study the composition and dynamic structure of the stratosphere, mesosphere, and lower thermosphere in the height range 20 to 100 km, the region known as the middle atmosphere. The MAS will be flown on the Atmospheric Laboratory for Applications and Science (ATLAS 1) NASA mission scheduled for late 1990. The Millimeter-Wave Atmospheric Sounder will provide, for the first time, information obtained simultaneously on the temperature and on ozone concentrations in the 20 to 90 km altitude region. The information will cover a large area of the globe, will have high accuracy and high vertical resolution, and will cover both day and night times. Additionally, data on the two important molecules, H2O and ClO, will also be provided.

  3. Contact Whiskers for Millimeter Wave Diodes

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.; Grange, J. A.; Lichtenberger, J. A.

    1978-01-01

    Several techniques are investigated for making short conical tips on wires (whiskers) used for contacting millimeter-wave Schottky diodes. One procedure, using a phosphoric and chromic acid etching solution (PCE), is found to give good results on 12 microns phosphor-bronze wires. Full cone angles of 60 degrees-80 degrees are consistently obtained, compared with the 15 degrees-20 degrees angles obtained with the widely used sodium hydroxide etch. Methods are also described for cleaning, increasing the tip diameter (i.e. blunting), gold plating, and testing the contact resistance of the whiskers. The effects of the whisker tip shape on the electrical resistance, inductance, and capacitance of the whiskers are studied, and examples given for typical sets of parameters.

  4. Thermoreflectance temperature measurement with millimeter wave.

    PubMed

    Pradere, C; Caumes, J-P; BenKhemis, S; Pernot, G; Palomo, E; Dilhaire, S; Batsale, J-C

    2014-06-01

    GigaHertz (GHz) thermoreflectance technique is developed to measure the transient temperature of metal and semiconductor materials located behind an opaque surface. The principle is based on the synchronous detection, using a commercial THz pyrometer, of a modulated millimeter wave (at 110 GHz) reflected by the sample hidden behind a shield layer. Measurements were performed on aluminum, copper, and silicon bulks hidden by a 5 cm thick Teflon plate. We report the first measurement of the thermoreflectance coefficient which exhibits a value 100 times higher at 2.8 mm radiation than those measured at visible wavelengths for both metallic and semiconductor materials. This giant thermoreflectance coefficient κ, close to 10(-3) K(-1) versus 10(-5) K(-1) for the visible domain, is very promising for future thermoreflectance applications.

  5. Thermoreflectance temperature measurement with millimeter wave

    SciTech Connect

    Pradere, C. Caumes, J.-P.; BenKhemis, S.; Palomo, E.; Batsale, J.-C.; Pernot, G.; Dilhaire, S.

    2014-06-15

    GigaHertz (GHz) thermoreflectance technique is developed to measure the transient temperature of metal and semiconductor materials located behind an opaque surface. The principle is based on the synchronous detection, using a commercial THz pyrometer, of a modulated millimeter wave (at 110 GHz) reflected by the sample hidden behind a shield layer. Measurements were performed on aluminum, copper, and silicon bulks hidden by a 5 cm thick Teflon plate. We report the first measurement of the thermoreflectance coefficient which exhibits a value 100 times higher at 2.8 mm radiation than those measured at visible wavelengths for both metallic and semiconductor materials. This giant thermoreflectance coefficient κ, close to 10{sup −3} K{sup −1} versus 10{sup −5} K{sup −1} for the visible domain, is very promising for future thermoreflectance applications.

  6. Millimeter wave spectra of carbonyl cyanide ⋆

    PubMed Central

    Bteich, S.B.; Tercero, B.; Cernicharo, J.; Motiyenko, R.A.; Margulès, L.; Guillemin, J.-C.

    2016-01-01

    Context More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. Aims The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. Methods The rotational spectrum of carbonyl cyanide was measured in the frequency range 152 - 308 GHz and analyzed using Watson’s A- and S-reduction Hamiltonians. Results The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources. PMID:27738349

  7. The millimeter-wave bolometric interferometer

    NASA Astrophysics Data System (ADS)

    Gault, Amanda Charlotte

    The Millimeter-wave Bolometric Interferometer (MBI) is a technology demonstrator for future searches for the B-mode polarization of the Cosmic Microwave Background (CMB). If observed, B-modes would be a direct probe of the energy scale of inflation, an energy scale that is impossible to reach with even the most sophisticated particle accelerators. In this thesis, I outline the technology differences between MBI and conventional interferometers, including the Faraday effect phase modulators (FPM) used both to control systematic effects and to allow for phase sensitive detection of signals. MBI is a four element adding interferometer with a Fizeau optical beam combiner. This allows simple scaling of the instrument to a large numbers of baselines without requiring complicated pair-wise correlations of signals. Interferometers have an advantage over imaging telescopes when measuring the CMB power spectrum as each baseline is sensitive to a single Fourier mode (angular scale) on the sky. Recovering individual baseline information with this combination scheme requires phase modulating the signal from each antenna. MBI performs this modulation with Faraday effect phase modulators. In these novel cryogenic devices a modulated magnetic field switches the phase of a millimeter-wave RF signal by +/- 90 degrees at frequencies up to a few Hertz. MBI's second season of observations occurred in the winter of 2009 at Pine Bluff Observatory a few miles west of Madsion, WI. We successfully observed interference fringes of a microwave test source located in the far field of the instrument that agree well with those expected from simulations. MBI has inspired a second generation bolometric interferometer, QUBIC, which will have hundreds of antennas and thousands of detectors. When it deploys in 2015, it will be sensitive enough to search for B-mode signals from the CMB.

  8. Millimeter wave spectra of carbonyl cyanide.

    PubMed

    Bteich, S B; Tercero, B; Cernicharo, J; Motiyenko, R A; Margulès, L; Guillemin, J-C

    2016-08-01

    More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. The rotational spectrum of carbonyl cyanide was measured in the frequency range 152 - 308 GHz and analyzed using Watson's A- and S-reduction Hamiltonians. The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources.

  9. Wave-Coupled Millimeter-Wave Electro-Optic Techniques

    DTIC Science & Technology

    2001-03-01

    This report details results on two antenna-coupled millimeter-wave electro - optic modulators, the slot-vee antenna-coupled modulator and a 94 GHz...study of the effects of velocity mismatch on linearized electro - optic modulators was made and the results published. A key result was that directional...drift in electro - optic modulators was made and protons were determined to be the cause. Several inventions were made to reduce or eliminate proton-caused bias drift.

  10. Millimeter Wave Metal-Insulator-Metal Detector/Mixer Diode.

    DTIC Science & Technology

    1983-12-01

    AO-A138 391 MILLIMETER WAVE METAL-INSULATOR- METAL DETECTOR /MIXER 1/1 DIODE(VI NORTH CAROLIN A AGRICULTURAL A NO TECHNI CA L STATE UNIV GREENSRO. C TV...163-A I V AFWAL-TR-83-1179 MILLIMETER WAVE METAL-INSULATOR- METAL DETECTOR /MIXER DIODE CHUNG YU NORTH CAROLINA A&T STATE UNIVERSITY GREENSBORO, NORTH...TITLE (ad subsorle.I S. TYPE CrjflT&PEO OER MILLIMETER WAVE May, 1981--July, 1983 METAL-INSULATOR- METAL DETECTOR /MIXER G. PERFORMING ORG. REPORT

  11. Millimeter wave detection of nuclear radiation: an alternative detection mechanism.

    PubMed

    Gopalsami, N; Chien, H T; Heifetz, A; Koehl, E R; Raptis, A C

    2009-08-01

    We present a nuclear radiation detection mechanism using millimeter waves as an alternative to conventional detection. It is based on the concept that nuclear radiation causes ionization of air and that if we place a dielectric material near the radiation source, it acts as a charge accumulator of the air ions. We have found that millimeter waves can interrogate the charge cloud on the dielectric material remotely. This concept was tested with a standoff millimeter wave system by monitoring the charge levels on a cardboard tube placed in an x-ray beam.

  12. Millimeter wave spectra of carbonyl cyanide

    NASA Astrophysics Data System (ADS)

    Bteich, S. B.; Tercero, B.; Cernicharo, J.; Motiyenko, R. A.; Margulès, L.; Guillemin, J.-C.

    2016-07-01

    Context. More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. Aims: The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. Methods: The rotational spectrum of carbonyl cyanide was measured in the frequency range 152-308 GHz and analyzed using Watson's A- and S-reduction Hamiltonians. Results: The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of

  13. Millimeter-wave radar sensing of airborne chemicals.

    SciTech Connect

    Gopalsami, N.; Raptis, A. C.; Energy Technology

    2001-04-01

    This paper discusses the development of a millimeter-wave radar chemical sensor for applications in environmental monitoring and arms-control treaty verification. The purpose of this paper is to investigate the use of fingerprint-type molecular rotational signatures in the millimeter-wave spectrum to sense airborne chemicals. The millimeter-wave sensor, operating in the frequency range of 225-315 GHz, can work under all weather conditions and in smoky and dusty environments. The basic configuration of the millimeter-wave sensor is a monostatic swept-frequency radar that consists of a millimeter-wave sweeper, a hot-electron bolometer or Schottky barrier detector, and a corner-cube reflector. The chemical plume to be detected is situated between the transmitter/detector and reflector. Millimeter-wave absorption spectra of chemicals in the plume are determined by measuring the swept-frequency radar return signals with and without the plume in the beam path. The problem of pressure broadening, which hampered open-path spectroscopy in the past, has been mitigated in this paper by designing a fast sweeping source over a broad frequency range. The heart of the system is a backward-wave oscillator (BWO) tube that can be tuned over 220-350 GHz. Using the BWO tube, we built a millimeter-wave radar system and field-tested it at the Department of Energy Nevada Test Site, Frenchman Flat, near Mercury, NV, at a standoff distance of 60 m, The millimeter-wave system detected chemical plumes very well; detection sensitivity for polar molecules such as methylchloride was down to 12 ppm for a 4-m two-way pathlength.

  14. Investigation of gigawatt millimeter wave source applications

    NASA Astrophysics Data System (ADS)

    Bruder, J. A.; Belcher, M. L.

    1991-09-01

    The Georgia Tech Research Institute (GTRI) investigated potential applications of millimeter wave (MMW) sources with peak powers on the order of a gigawatt. This power level is representative of MMW devices such as the free electron laser (FEL) and the cyclotron auto-resonance maser (CARM) that are under development at the Lawrence Livermore National Laboratory (LLNL). In addition to determining the technical requirements for these applications, the investigation considered potential users and how a high power MMW system would expand their current capabilities. Two of the more promising applications were examined in detail to include trade-off evaluations system parameters. The trade-off evaluations included overall system configuration, frequency and coherence, component availability, and performance estimates. Brainstorming sessions were held to try and uncover additional applications for a gigawatt MMW source. In setting up guidelines for the session, the need to attempt to predict applications for the years 2000 to 2030 was stressed. Also, possible non-DoD applications needed to be considered. While some of these applications could not in themselves justify the costs involved in the development of the radar system, they could be considered potential secondary applications of the system. As a result of the sessions, a number of interesting potential applications evolved including: space object identification; low angle tracking; illuminator for space-based radar; radio astronomy; space vehicle navigation; space debris location; atmospheric research; wind shear detection; electronic countermeasures; low observable detection; and long range detection via ducting.

  15. Millimeter-wave detection of landmines

    NASA Astrophysics Data System (ADS)

    Öztürk, Hilmi; Nazli, Hakki; Yeǧin, Korkut; Biçak, Emrullah; Sezgin, Mehmet; Daǧ, Mahmut; Turetken, Bahattin

    2013-06-01

    Millimeter wave absorption relative to background soil can be used for detection landmines with little or no metal content. At these frequencies, soil and landmine absorb electromagnetic energy differently. Stepped frequency measurements from 20 GHz to 60 GHz were used to detect buried surrogate landmines in the soil. The targets were 3 cm and 5 cm beneath the soil surface and coherent transmission and reflection was used in the experimental setup. The measurement set-up was mounted on a handheld portable device, and this device was on a rail for accurate displacement such that the rail could move freely along the scan axis. Measurements were performed with network analyzer and scattering data in frequency domain were recorded for processing, namely for inverse Fourier Transform and background subtraction. Background subtraction was performed through a numerical filter to achieve higher contrast ratio. Although the numerical filter used was a simple routine with minimal computational burden, a specific detection method was applied to the background subtracted GPR data, which was based on correlation summation of consecutive A-scan signals in a predefined window length.

  16. Investigation of gigawatt millimeter wave source applications

    SciTech Connect

    Bruder, J.A.; Belcher, M.L.

    1991-09-01

    The Georgia Tech Research Institute (GTRI) investigated potential applications of millimeter wave (MMW) sources with peak powers on the order of a gigawatt. This power level is representative of MMW devices such as the free electron laser (FEL) and the cyclotron auto-resonance maser (CARM) that are under development at the Lawrence Livermore National Laboratory (LLNL). In addition to determining the technical requirements for these applications, the investigation considered potential users and how a high power MMW system would expand their current capabilities. Two of the more promising applications were examined in detail to include trade-off evaluations system parameters. The trade-off evaluations included overall system configuration, frequency and coherence, component availability, and performance estimates. Brainstorming sessions were held to try and uncover additional applications for a gigawatt MMW source. In setting up guidelines for the session, the need to attempt to predict applications for the years 2000 to 2030 was stressed. Also, possible non-DoD applications needed to be considered. While some of these applications could not in themselves justify the costs involved in the development of the radar system, they could be considered potential secondary applications of the system. As a result of the sessions, a number of interesting potential applications evolved including: space object identification; low angle tracking; illuminator for space-based radar; radio astronomy; space vehicle navigation; space debris location; atmospheric research; wind shear detection; electronic countermeasures; low observable detection; and long range detection via ducting.

  17. Hexagonal ferrites for millimeter wave applications

    NASA Astrophysics Data System (ADS)

    Polk, Donald E.; Hathaway, Kristl B.

    1993-01-01

    A review of the work accomplished on this contract is presented. A review of the physics of hexagonal ferrite materials and the effective linewidth concept and the detailed overall research plan are contained in the original proposal document. The focus of the program was on the effective linewidth in millimeter wave materials, including planar hexagonal ferrite Y-type materials, uniaxial M-type materials, and thin ferromagnetic transition metal and alloy films. The key idea in the original proposal was that the ferromagnetic resonance (FMR) linewidth in hexagonal ferrites is dominated by inhomogeneous and two-magnon scattering losses and that off-resonance measurements of the effective linewidth would (1) show that the FMR losses do not represent the intrinsic losses, and (2) that the intrinsic losses are significantly lower. This basic idea was verified. Results were obtained on the off-resonance far-field effective linewidth in planar Zn-Y hexagonal ferrite single crystal platelets, single crystal spheres of Ba- and Sr-hexaferrite materials, and permalloy thin films. Three papers on these results were published.

  18. Progress in millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Wikner, David A.

    2011-03-01

    The field of millimeter-wave (MMW) imaging has progressed significantly over the last two decades. The most obvious evidence of this is the widespread use of MMW full-body scanners, now commonly found in airports. The path to this point has been the result of the work of a wide range of experts from many scientific and engineering disciplines. This article represents one perspective of this progress. The development of MMW imagers, and all their associated component technologies, image processing techniques, clever engineering, etc. has been driven by a relatively small number of interesting applications. It has been known for about 70 years that RF energy can be used to "see" through things like clouds and detect, for example, hostile aircraft. As the RF frequency goes up to 35, 100, or 340 GHz, it becomes possible to image through obscurants with much improved resolution. However, as frequency increases, attenuation increases as well, so selecting the right frequency for the application is an important point. The challenge of seeing through obscurants such as fog, smoke and dust drives one towards a MMW imaging solution. Typical applications include guiding aircraft through low visibility conditions, detecting nearby watercraft in the fog, and searching for concealed weapons. So, while these capabilities have been demonstrated numerous times over the years, the practical and affordable implementation of the systems to accomplish these goals is where the real story lies.

  19. The Millimeter-Wave Bolometric Interferometer

    NASA Astrophysics Data System (ADS)

    Korotkov, Andrei; Ade, P. A.; Ali, S.; Bierman, E.; Bunn, E. F.; Calderon, C.; Gault, A. C.; Hyland, P. O.; Keating, B. G.; Kim, J.; Malu, S. S.; Mauskopf, P. D.; Murphy, J. A.; O'Sullivan, C.; Piccirillo, L.; Timbie, P. T.; Tucker, G. S.; Wandelt, B. D.

    2006-12-01

    We report on the status of the Millimeter-Wave Bolometric Interferometer (MBI), an instrument designed for polarization measurements of the cosmic microwave background (CMB). MBI combines the differencing capabilities of an interferometer with the high sensitivity of bolometers. The design of the ground-based four-channel version of the instrument with 7-degree-FOV corrugated horns (MBI-4) and first measurements results are discussed. Corrugated horn antennas with low sidelobes and nearly symmetric beam patterns minimize spurious instrumental polarization. The MBI-4 optical band is limited by filters with a central frequency of 90 GHz. The antenna separation is chosen so the instrument is sensitive over the multipole range l=150-270. In MBI-4, the signals from antennas are combined with a quasi-optical Fizeau beam combiner and interference fringes are detected by an array of spider-web bolometers with NTD germanium thermistors. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. First observations will be from the Pine Bluff Observatory outside Madison, WI. The project is supported by NASA.

  20. Superconducting submillimeter and millimeter wave detectors

    SciTech Connect

    Nahum, Michael

    1992-10-20

    The series of projects described in this dissertation was stimulated by the discovery of high temperature superconductivity. Our goal was to develop useful applications which would be competitive with the current state of technology. The high-Tc microbolometer was developed into the most sensitive direct detector of millimeter waves, when operated at liquid nitrogen temperatures. The thermal boundary resistance of thin YBa2Cu307-δ films was subsequently measured and provided direct evidence for the bolometric response of high-Tc films to fast (ns) laser pulses. The low-Tc microbolometer was developed and used to make the first direct measurements of the frequency dependent optical efficiency of planar lithographed antennas. The hot-electron microbolometer was invented less than a year prior to the writing of this dissertation. Our analysis, presented here, indicates that it should be possible to attain up to two orders of magnitude higher sensitivity than that of the best available direct detectors when operated at the same temperature. The temperature readout scheme for this device could also be used to measure the intrinsic interaction between electrons and phonons in a metal with a sensitivity that is five orders of magnitude better than in previous measurements. Preliminary measurements of quasiparticle trapping effects at the interface between a metal and a superconductor are also presented.

  1. Millimeter-wave imaging for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.

    2003-07-01

    Full body, real-time, millimeter-wave imaging systems have been developed at the Pacific Northwest National Laboratory for the detection of body-worn, concealed weapons and contraband at security checkpoints. These security systems employ methods derived from microwave holography techniques that utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited for the detection of concealed weapons or other contraband carried on personnel, since millimeter waves are non-ionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, wide-bandwidth, three-dimensional, holographic microwave imaging techniques and a full-body, planar, millimeter-wave imaging system are described.

  2. Millimeter-wave imaging for concealed weapon detection

    SciTech Connect

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.

    2003-07-16

    Full-body, real-time, millimeter-wave imaging systems have been developed at the Pacific Northwest National Laboratory for the detection of body-worn, concealed weapons and contraband at security checkpoints. These security systems employ methods derived from microwave holography techniques that utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited for the detection of concealed weapons or other contraband carried on personnel, since millimeter waves are non-ionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, wide-bandwidth, three-dimensional, holographic microwave imaging techniques and a full-body, planar, millimeter-wave imaging system are described.

  3. Monolithic millimeter-wave and picosecond electronic technologies

    SciTech Connect

    Talley, W.K.; Luhmann, N.C.

    1996-03-12

    Theoretical and experimental studies into monolithic millimeter-wave and picosecond electronic technologies have been undertaken as a collaborative project between the Lawrence Livermore National Laboratory (LLNL) and the University of California Department of Applied Science Coherent Millimeter-Wave Group under the auspices of the Laboratory Directed Research and Development Program at LLNL. The work involves the design and fabrication of monolithic frequency multiplier, beam control, and imaging arrays for millimeter-wave imaging and radar, as well as the development of high speed nonlinear transmission lines for ultra-wideband radar imaging, time domain materials characterization and magnetic fusion plasma applications. In addition, the Coherent Millimeter-Wave Group is involved in the fabrication of a state-of-the-art X-band ({approximately}8-11 GHz) RF photoinjector source aimed at producing psec high brightness electron bunches for advanced accelerator and coherent radiation generation studies.

  4. An Ultra-Wideband Millimeter-Wave Phased Array

    NASA Technical Reports Server (NTRS)

    Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

    2016-01-01

    Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

  5. Radar applications of gigawatt sources at millimeter wave frequencies

    SciTech Connect

    Bruder, J.A.; Belcher, M.L. . Research Inst.)

    1991-06-01

    The high transmit powers provided by free electron laser (FEL) sources in combination with the narrow antenna beamwidths achievable at millimeter wave (MMW) frequencies offer potential for use in a number of radar applications. Potential applications of high power millimeter wave sources include satellite imaging, low angle radar tracking, radar astronomy, and a number of other possible applications such as atmospheric research, space debris detection, and space vehicle tracking. 3 refs., 3 figs.

  6. Millimeter Wave Cloud Radar (MMCR) Handbook

    SciTech Connect

    KB Widener; K Johnson

    2005-01-30

    The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

  7. Study of Novel Slow Wave Circuit for Miniaturized Millimeter Wave Helical Traveling Wave Tube

    NASA Astrophysics Data System (ADS)

    Li, Bin; Zhu, Xiaofang; Liao, Li; Yang, Zhonghai; Zeng, Baoqing; Yao, Lieming

    2006-07-01

    Two kinds of novel helical slow wave circuit, supported by Chemical Vapor Deposition (CVD) diamond, are presented. They are applying in miniaturized millimeter wave helical traveling wave tube. Cold test characteristic of these circuits are simulated by MAFIA code. Higher performances are achieved with smaller size, compared with conventional circuit supported by BeO rods. The nonlinear analysis is implemented by Beam and Wave Interaction (BWI) module, which is a part of TWTCAD Integrated Framework. Results have been found to be consistent with the expectation. It should be wider apply in microwave and millimeter wave vacuum electronic devices.

  8. Graphical design of millimeter-wave finline bandpass filters

    NASA Astrophysics Data System (ADS)

    Nguyen, Cam

    1987-12-01

    A very simple yet accurate design procedure for the finline bandpass filters at millimeter wavelengths is presented. The technique enables the geometry of finline bandpass filters to be obtained accurately from simple closed-form equations and curves. Using this graphical approach, various millimeter-wave finline bandpass filters have been designed. Results in V-band (50 to 75 GHz) and W-band (75 to 110 GHz) are presented and indicate a good agreement between the calculated and measured performances.

  9. Investigation of Millimeter Wave Propagation in the Atmosphere.

    DTIC Science & Technology

    1986-07-18

    fluxes, absorption, refractive- index fluctuations C= AfTUACT (IMueftwwin if neweas iy md identt I by block ntmwwb)F This report documents the results of... Technology (GIT), whose exper- tise in millimeter wave sources and receivers is reknown, were co-investigators. The GIT responsibility was to develop...we could eliminate the need for the labor-intensive radio refractometer needed to measure the refrac- tive- index fluctuations in the near millimeter

  10. Amplifier based broadband pixel for sub-millimeter wave imaging

    NASA Astrophysics Data System (ADS)

    Sarkozy, Stephen; Drewes, Jonathan; Leong, Kevin M. K. H.; Lai, Richard; Mei, X. B. (Gerry); Yoshida, Wayne; Lange, Michael D.; Lee, Jane; Deal, William R.

    2012-09-01

    Broadband sub-millimeter wave technology has received significant attention for potential applications in security, medical, and military imaging. Despite theoretical advantages of reduced size, weight, and power compared to current millimeter wave systems, sub-millimeter wave systems have been hampered by a fundamental lack of amplification with sufficient gain and noise figure properties. We report a broadband pixel operating from 300 to 340 GHz, biased off a single 2 V power supply. Over this frequency range, the amplifiers provide > 40 dB gain and <8 dB noise figure, representing the current state-of-art performance capabilities. This pixel is enabled by revolutionary enhancements to indium phosphide (InP) high electron mobility transistor technology, based on a sub-50 nm gate and indium arsenide composite channel with a projected maximum oscillation frequency fmax>1.0 THz. The first sub-millimeter wave-based images using active amplification are demonstrated as part of the Joint Improvised Explosive Device Defeat Organization Longe Range Personnel Imager Program. This development and demonstration may bring to life future sub-millimeter-wave and THz applications such as solutions to brownout problems, ultra-high bandwidth satellite communication cross-links, and future planetary exploration missions.

  11. Passive millimeter-wave imaging: seeing in very poor visibility

    NASA Astrophysics Data System (ADS)

    Appleby, Roger; Price, Sean; Gleed, David G.; Lettington, Alan H.

    1995-06-01

    It is more common to use the visible or infrared regions to image although it is possible to use millimeter waves. Passive millimeter wave imaging, however, has the advantage of being able to see in poor weather conditions such as in thick fog. The images, unlike radar signatures, have a natural appearance that can be easily interpreted. The spatial resolution of these imagers is limited by the aperture size and choice of operating frequency. Novel signal processing algorithms have been applied to improve the spatial resolution. Millimeter wave imagers detect slight temperature differences in the scene and using current technology it is possible to sense changes as low as 0.2 K whilst the contrast between an aircraft and its background can be as high as 200 K. A millimetric imager has been used at London Heathrow airport to demonstrate the high quality of the images that can be obtained. Aircraft can be recognized, runways and grass delineated and complex areas such as gates imaged. A qualitative comparison has been made of radar, thermal imaging and passive millimeter wave imaging for ground movement control. The possibility of deploying a passive millimeter wave imager on a commercial aircraft and of using it as part of an enhanced vision system is also discussed.

  12. Passive millimeter-wave imaging model application and validation

    NASA Astrophysics Data System (ADS)

    Blume, Bradley T.; Chenault, David B.

    1997-06-01

    The military use of millimeter wave radiometers has been studied since the 1960's. It is only recently that advances in the technology have made passive millimeter wave (PMMW) systems practical. It is well established that metal targets will have a large contrast ratio versus the background in the millimeter wave (MMW) regime and that atmospheric propagation through clouds, fog and light rain is possible. The limitations have been the noise figures of the detectors, the size of the systems, and the cost of the systems. Through the advent of millimeter wave monolithic integrated circuits technology, MMW devices are becoming smaller, more sensitive, and less expensive. In addition many efforts are currently under way to develop PMMW array imaging devices. This renewed interest has likewise brought forth the need for passive millimeter wave system modeling capabilities. To fill this need, Nichols Research Corporation has developed for Eglin AFB a physics-based image synthesis code, capable of modeling the dominant effects in the MMW regime. This code has been developed to support the development of the next generation of PMMW seeker systems. This paper will describe the phenomenology of PMMW signatures, the Irma software, validation of the Irma models and the application of the models to both Air Force and Navy problems.

  13. AC/RF Superconductivity

    SciTech Connect

    Ciovati, Gianluigi

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  14. Millimeter-wave spectra of the Jovian planets

    NASA Technical Reports Server (NTRS)

    Joiner, Joanna; Steffes, Paul G.

    1991-01-01

    The millimeter wave portion of the electromagnetic spectrum is critical for understanding the subcloud atmospheric structure of the Jovian planets (Jupiter, Saturn, Uranus, and Neptune). This research utilizes a combination of laboratory measurements, computer modeling, and radio astronomical observation in order to obtain a better understanding of the millimeter-wave spectra of the Jovian planets. The pressure broadened absorption from gaseous ammonia (NH3) and hydrogen sulfide (H2S) was measured in the laboratory under simulated conditions for the Jovian atmospheres. Researchers developed new formalisms for computing the absorptivity of gaseous NH3 and H2S based on their laboratory measurements. They developed a radiative transfer and thermochemical model to predict the abundance and distribution of absorbing constituents in the Jovian atmospheres. They used the model to compute the millimeter wave emission from the Jovian planets.

  15. Millimeter-wave technology advances since 1985 and future trends

    NASA Astrophysics Data System (ADS)

    Meinel, Holger H.

    1991-05-01

    The author focuses on finline or E-plane technology. Several examples, including AVES, a 61.5-GHz radar sensor for traffic data acquisition, are included. Monolithic integrated 60- and 94-GHz receiver circuits composed of a mixer and IF amplifier in compatible FET technology on GaAs are presented to show the state of the art in this area. A promising approach to the use of silicon technology for monolithic millimeter-wave integrated circuits, called SIMMWIC, is described as well. As millimeter-wave technology has matured, increased interest has been generated for very specific applications: (1) commercial automotive applications such as intelligent cruise control and enhanced vision have attracted great interest, calling for a low-cost design approach; and (2) an almost classical application of millimeter-wave techniques is the field of radar seekers, e.g., for intelligent ammunitions, calling for high performance under extreme environmental conditions. Two examples fulfilling these requirements are described.

  16. ATS-F Comsat Millimeter Wave Propagation Experiment

    NASA Technical Reports Server (NTRS)

    Westerlund, L. H.; Levatich, J. L.; Buige, A.

    1973-01-01

    The ATS-F Comsat Millimeter Wave Propagation Experiment has been designed to gather statistical data on the attenuation caused by rain at millimeter wave frequencies. These data will be used to determine system design parameters for future communications satellite systems operating at frequencies above 10 GHz. The experiment has 39 ground terminals transmitting at 13.2 or 17.8 GHz to a transponder on board the ATS-F satellite. The transponder retransmits these signals at 4 GHz to a central earth terminal which records their amplitudes once each second. The data will be analyzed to provide probabilities of attenuation as functions of parameters such as rainfall, location, and time. These probabilities can then be used to determine the required power margins of millimeter wave communications systems. Techniques of overcoming severe attenuation such as site diversity and the use of a spot beam to increase the power level at selected locations will also be evaluated.

  17. Millimeter-wave micro-Doppler measurements of small UAVs

    NASA Astrophysics Data System (ADS)

    Rahman, Samiur; Robertson, Duncan A.

    2017-05-01

    This paper discusses the micro-Doppler signatures of small UAVs obtained from a millimeter-wave radar system. At first, simulation results are shown to demonstrate the theoretical concept. It is illustrated that whilst the propeller rotation rate of the small UAVs is quite high, millimeter-wave radar systems are capable of capturing the full micro-Doppler spread. Measurements of small UAVs have been performed with both CW and FMCW radars operating at 94 GHz. The CW radar was used for obtaining micro-Doppler signatures of individual propellers. The field test data of a flying small UAV was collected with the FMCW radar and was processed to extract micro-Doppler signatures. The high fidelity results clearly reveal features such as blade flashes and propeller rotation modulation lines which can be used to classify targets. This work confirms that millimeter-wave radar is suitable for the detection and classification of small UAVs at usefully long ranges.

  18. Millimeter Wave Radar for detecting the speech signal applications

    NASA Astrophysics Data System (ADS)

    Li, Zong-Wen

    1996-12-01

    MilliMeter Wave (MMW) Doppler Radar with grating structures for the applications of detecting speech signals has been discovered in our laboratory. The operating principle of detection the acoustic wave signals based on the Wave Propagation Theory and Wave Equations of The ElectroMagnetic Wave (EMW) and Acoustic Wave (AW) propagating, scattering, reflecting and interacting has been investigated. The experimental and observation results have been provided to verify that MMW CW 40GHz dielectric integrated radar can detect and identify out exactly the existential speech signals in free space from a person speaking. The received sound signal have been reproduced by the DSP and the reproducer.

  19. Millimeter-wave detection using resonant tunnelling diodes

    NASA Technical Reports Server (NTRS)

    Mehdi, I.; Kidner, C.; East, J. R.; Haddad, G. I.

    1990-01-01

    A lattice-matched InGaAs/InAlAs resonant tunnelling diode is studied as a video detector in the millimeter-wave range. Tangential signal sensitivity and video resistance measurements are made as a function of bias and frequency. A tangential signal sensitivity of -37 dBm (1 MHz amplifier bandwidth) with a corresponding video resistance of 350 ohms at 40 GHz has been measured. These results appear to be the first millimeter-wave tangential signal sensitivity and video resistance results for a resonant tunnelling diode.

  20. The influence of polarization on millimeter wave propagation through rain

    NASA Technical Reports Server (NTRS)

    Bostian, C. W.; Stutzman, W. L.

    1972-01-01

    A program for the measurement and analysis of the depolarization and differential attenuation that occur when millimeter wave signals propagate through rain is described. Initial data are taken along a 1.43 km path at 17.65 GHz and a supporting theoretical model is developed to relate the propagation effects to rainfall rate and wind velocity. A block diagram of the overall experiment is included. It consists of: (1) an RF system (millimeter wave transmitter and receiver), (2) transmitting and receiving antennas, (3) a weather system with rain gauges, wind sensors, and drop counters, and (4) a digital control, processing, and data storage system.

  1. Microsystem integration from RF to millimeter wave applications

    NASA Astrophysics Data System (ADS)

    Vähä-Heikkilä, T.; Lahti, M.

    2015-05-01

    Radio frequency systems have been applied successfully to consumer products. Typically these radios operate up to 6 GHz. During recent years, interest towards microwave (up to 30 GHz) and millimeter wave frequencies (30 ... 300 GHz) has increased significantly. Technologies have been developed to have high performance microwave and millimeter wave components. On the other hand, integration and packaging technologies have not developed as fast while their importance is crucial especially in consumer applications. This presentation focuses to latest trends in wireless microsystem component integration and packaging trends backed up with demonstrators and measured results based on VTT's demonstrations.

  2. Low Noise Amplifier Receivers from Millimeter Wave Atmospheric Remote Sensing

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka; Lim, Boon; Gaier, Todd; Tanner, Alan; Varonen, Mikko; Samoska, Lorene; Brown, Shannon; Lambrigsten, Bjorn; Reising, Steven; Tanabe, Jordan; Montes, Oliver; Dawson, Douglas; Parashare, Chaitali

    2012-01-01

    We currently achieve 3.4 dB noise figure at 183GHz and 2.1 dB noise figure at 90 GHz with our MMIC low noise amplifiers (LNAs) in room temperature. These amplifiers and the receivers we have built using them made it possible to conduct highly accurate airborne measurement campaigns from the Global Hawk unmanned aerial vehicle, develop millimeter wave internally calibrated radiometers for altimeter radar path delay correction, and build prototypes of large arrays of millimeter receivers for a geostationary interferometric sounder. We use the developed millimeter wave receivers to measure temperature and humidity profiles in the atmosphere and in hurricanes as well as to characterize the path delay error in ocean topography altimetry.

  3. Low Noise Amplifier Receivers from Millimeter Wave Atmospheric Remote Sensing

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka; Lim, Boon; Gaier, Todd; Tanner, Alan; Varonen, Mikko; Samoska, Lorene; Brown, Shannon; Lambrigsten, Bjorn; Reising, Steven; Tanabe, Jordan; hide

    2012-01-01

    We currently achieve 3.4 dB noise figure at 183GHz and 2.1 dB noise figure at 90 GHz with our MMIC low noise amplifiers (LNAs) in room temperature. These amplifiers and the receivers we have built using them made it possible to conduct highly accurate airborne measurement campaigns from the Global Hawk unmanned aerial vehicle, develop millimeter wave internally calibrated radiometers for altimeter radar path delay correction, and build prototypes of large arrays of millimeter receivers for a geostationary interferometric sounder. We use the developed millimeter wave receivers to measure temperature and humidity profiles in the atmosphere and in hurricanes as well as to characterize the path delay error in ocean topography altimetry.

  4. The Millimeter-Wave Spectrum of Propanal

    NASA Astrophysics Data System (ADS)

    Zingsheim, Oliver; Müller, Holger S. P.; Lewen, Frank; Schlemmer, Stephan

    2017-06-01

    The microwave spectrum of propanal, also known as propionaldehyde, CH_3CH_2CHO, has been investigated in the laboratory already since 1964^1 and has also been detected in space^2. Recently, propanal was detected with the Atacama Large Millimeter/submillimeter Array (ALMA), Protostellar Interferometric Line Survey (PILS)^3. The high sensitivity and resolution of ALMA indicated small discrepancies between observed and predicted rotational spectra of propanal. As higher accuracies are desired the spectrum of propanal was measured up to 500 GHz with the Cologne (Sub-)Millimeter spectrometer. Propanal has two stable conformers, syn and gauche, which differ mainly in the rotation of the aldehyd group with respect to the rigid C-atom framework of the molecule. We extensively studied both of them. The lower syn-conformer shows small splittings caused by the internal rotation of the methyl group, whereas the spectrum of gauche-propanal is complicated due to the tunneling rotation interaction from two stable degenerate conformers. Additionally, we analyzed vibrationally excited states. ^1 Butcher et al., J. Chem. Phys. 40 6 (1964) ^2 Hollis et al., Astrophys. J. 610 L21 (2004) ^3 Lykke et al., A&A 597 A53 (2017)

  5. External calibration technique of millimeter-wave cloud radar

    NASA Astrophysics Data System (ADS)

    Wen, Tao; Zhao, Zeng-Liang; Yao, Zhi-Gang; Han, Zhi-Gang; Guo, Lin-Da

    2016-10-01

    The millimeter-wave cloud radar can provide a large number of fine and reliable information for the inversion of cloud macro and micro parameters. A key link of using the millimeter-wave cloud radar to detect the cloud is that the radar must be calibrated. Due to the precision components and severe environment of millimeter-wave cloud radar, subtle changes may take place in the operation process of cloud radar, unless the cloud radar is calibrated regularly. Although the calibration system inside the cloud radar can track and monitor the main working parameters and correct the detection results, it fails to consider the characteristics of the antenna and the mutual influence among different components of cloud radar. Therefore, the external calibration for cloud radar system is very important. Combined with the actual situation of cloud radar under domestic onboard platform, this paper builds a complete external calibration technique process of cloud radar based on the calm sea, providing the theoretical support for the external calibration experiments of the airborne and even satellite-borne millimeter-wave cloud radar developed by our country.

  6. A compendium of millimeter wave propagation studies performed by NASA

    NASA Technical Reports Server (NTRS)

    Kaul, R.; Rogers, D.; Bremer, J.

    1977-01-01

    Key millimeter wave propagation experiments and analytical results were summarized. The experiments were performed with the Ats-5, Ats-6 and Comstar satellites, radars, radiometers and rain gage networks. Analytic models were developed for extrapolation of experimental results to frequencies, locations, and communications systems.

  7. Dayem bridge Josephson junctions. [for millimeter wave mixer

    NASA Technical Reports Server (NTRS)

    Barr, D. W.; Mattauch, R. J.

    1977-01-01

    The Josephson junction shows great promise as a millimeter wave mixer element. This paper discusses the physical mixing process from a first-order mathematical approach. Design and fabrication of such structures tailored for use in a 80-120 GHz mixer application is presented. Testing of the structures and a discussion of their interpretation is presented.

  8. Measurement of the effective linewidth in the millimeter waves range

    SciTech Connect

    Labeyrie, M.; Mage, J.C.; Ganne, J.P.

    1988-11-15

    An experimental setup is presented to measure the effective linewidth in the millimeter waves range. It uses the existence of magnetic modes just above the top of the manifold (versus field). This new method is used in order to characterize strontium and barium hexaferrite at 94 GHz between 77 and 300 K.

  9. Measurement of the effective linewidth in the millimeter waves range

    NASA Astrophysics Data System (ADS)

    Labeyrie, M.; Mage, J. C.; Ganne, J. P.

    1988-11-01

    An experimental setup is presented to measure the effective linewidth in the millimeter waves range. It uses the existence of magnetic modes just above the top of the manifold (versus field). This new method is used in order to characterize strontium and barium hexaferrite at 94 GHz between 77 and 300 K.

  10. Millimeter-wave dielectric properties of infrared window materials

    NASA Astrophysics Data System (ADS)

    Ho, W. W.

    1987-01-01

    The millimeter-wave dielectric properties of a series of IR window materials were determined over the temperature range 23-1000 C. Materials studied included Al2O3, ZnS, ZnSe, aluminum oxynitride (ALON), and magnesium-spinel (MgAl2O4). These materials all exhibited fairly high millimeter-wave dielectric constants, but with essentially negligible room-temperature losses for most applications. However, both the dielectric constant and loss tangent increase significantly with increasing temperatures. The increases in dielectric constant with temperature can be analyzed in terms of a macroscopic dielectric virial expansion model, and are primarily due to the effective increase in volume for each polarizable unit of the material. Consequently, a strategy to overcome this degradation would be to search for new materials or composite structures with low thermal expansion coefficients. The observed millimeter-wave loss properties are characteristic of contributions from intergranular impurities and show an onset of increased absorption at about 500. However, even at 1000 C, typical loss tangents are still below 0.05, and should be acceptable in most millimeter-wave window applications for reasonable thicknesses.

  11. Millimeter-Wave Propagation and Remote Sensing of the Atmosphere,

    DTIC Science & Technology

    1983-12-01

    tool to probe lower atmospheric structure. The principal applications of millimeter waves have been in the areas of communications, radar, and remote ... sensing . The availability of large bandwidths makes this region of the spectrum particularly attractive for high data rate communications. Because

  12. A Robust Waveguide Millimeter-Wave Noise Source

    NASA Technical Reports Server (NTRS)

    Ehsan, Negar; Piepmeier, Jeffrey R.; Solly, Michael; Macmurphy, Shawn; Lucey, Jared; Wollack, Edward

    2015-01-01

    This paper presents the design, fabrication, and characterization of a millimeter-wave noise source for the 160- 210 GHz frequency range. The noise source has been implemented in an E-split-block waveguide package and the internal circuitry was developed on a quartz substrate. The measured excess noise ratio at 200 GHz is 9.6 dB.

  13. Improved passive millimeter-wave imaging from a helicopter platform

    NASA Astrophysics Data System (ADS)

    Martin, Christopher A.; Kolinko, Vladimir G.

    2004-08-01

    A second-generation passive millimeter-wave imaging system is being prepared for flight testing on a UH-1H "Huey" helicopter platform. Passive millimeter-wave sensors form images through collection of blackbody emissions in the millimeter-wave portion of the electromagnetic spectrum. Radiation at this wavelength is not significantly scattered or absorbed by fog, clouds, smoke, or fine dust, which may blind other electro-optic sensors. Additionally, millimeter-wave imagery depends on a phenomenology based on reflection rather than emission, which produces a high level of contrast for metal targets. The system to be flight tested operates in the W-band region of the spectrum at a 30 Hz frame rate. The field-of-view of the system is 20 x 30 degrees and the system temperature resolution is less than 3 degrees. The system uses a pupil-plane phased-array architecture that allows the large aperture system to retain a compact form factor appropriate for airborne applications. The flight test is to include demonstrations of navigation with the system in a look-forward mode, targeting and reconnaissance with the system in a look down mode at 45 degrees, and landing aid with the system looking straight down. Potential targets include military and non-military vehicles, roads, rivers, and other landmarks, and terrain features. The flight test is scheduled to be completed in April 2004 with images available soon thereafter.

  14. Active Millimeter-Wave and Sub-Millimeter-Wave Imaging for Security Applications

    SciTech Connect

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2011-09-02

    Active imaging at millimeter and sub-millimeter wavelengths has been developed for security applications including concealed weapon detection. The physical properties that affect imaging performance are discussed along with a review of the current state-of-the-art and future potential for security imaging systems.

  15. Sensitivity of Josephson-effect millimeter-wave radiometer

    NASA Technical Reports Server (NTRS)

    Ohta, H.; Feldman, M. J.; Parrish, P. T.; Chiao, R. Y.

    1974-01-01

    The noise temperature and the minimum detectable temperature of a Josephson junction in video detection of microwave and millimeter-wave radiation has been calculated. We use the well-known method based on a Fokker-Planck equation. The noise temperature can be very close to ambient temperature. Because its predetection bandwidth is very wide, a Josephson-effect radio telescope receiver can have a minimum detectable temperature better than that of a traveling-wave maser.

  16. Present status and trend of technological developments for millimeter wave sensing systems

    NASA Astrophysics Data System (ADS)

    Ihara, Toshio; Okamoto, Ken'ichi; Kitamura, Katsumi; Awaka, Jun; Manabe, Takeshi

    1989-06-01

    Millimeter wave atmospheric propagation characteristics and state-of-the-art millimeter wave component technologies are reviewed. Particular attention is given to the current status of technological developments for millimeter wave sensing systems such as automotive radars, automatic location identification systems, and industrial instrumentation radars.

  17. Millimeter wave technology III; Proceedings of the Meeting, Arlington, VA, April 9, 10, 1985

    SciTech Connect

    Wiltse, J.C.

    1985-01-01

    Various papers on millimeter wave technology are presented. The subjects addressed include: high-power millimeter and submillimeter wave lasers and gyrotrons, GaAs IMPATT sources, InP Gunn diode sources, phase and frequency control of millimeter wave source, the Fresnel zone-plate lens, uniform waveguide leaky wave antennas, microstrip dipole antennas on electrically thick substrates, measurement of antenna patterns at 94 GHz using infrared detection, and transitions in open millimeter waveguides. Also discussed are: millimeter wave subassembly packaging techniques, recent advances in millimeter wave integrated circuits and subsystems, millimeter wave active solid state devices, applications of millimeter wave imaging, contrast reversal in MMW radiometric imaging, detection of stationary ground targets by airborne MMW radars, millimeter wave polarimetric background measurements, coherent 96 GHz high power radar, high-resolution 986 GHz FM-CW solid state radar, integrated circuit radar and radiometric sensors, millimeter-wave six-ports, atmospheric turbulence measuring system, near-millimeter wave propagation instrumentation, and millimeter wave measurement by Fabry-Perot.

  18. Design of Layered Ridge Dielectric Waveguide for Millimeter and Sub-Millimeter Wave Circuits

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Katehi, Linda P. B.

    1997-01-01

    Design rules for Layered Ridge Dielectric Waveguide (LRDW) are presented for the first time through simple figures and closed form equations. The Effective Dielectric Constant (EDC) method is used to develop the design rules that account for typical circuit specifications such as higher order mode suppression, dispersion, attenuation, and coupling between adjacent transmission lines. Comparisons between the design of LRDW, image guide, and millimeter-wave dielectric ridge guide are made.

  19. Circularly Polarized Millimeter-Wave Imaging for Personnel Screening

    SciTech Connect

    Sheen, David M.; McMakin, Douglas L.; Lechelt, Wayne M.; Griffin, Jeffrey W.

    2005-08-01

    A novel polarimetric millimeter-wave imaging technique has been developed at the Pacific Northwest National Laboratory (PNNL) for concealed weapon detection applications. Wideband millimeter-wave imaging systems developed at PNNL utilize low-power, coherent, millimeter-wave illumination in the 10-100 GHz range to form high-resolution images of personnel. Electromagnetic waves in these frequency ranges easily penetrate most clothing materials and are reflected from the body and any concealed items. Three-dimensional images are formed using computer image reconstruction algorithms developed to mathematically focus the received wavefronts scattered from the target. Circular polarimetric imaging can be employed to obtain additional information from the target. Circularly polarized waves incident on relatively smooth reflecting targets are typically reversed in their rotational handedness, e.g. left-hand circular polarization (LHCP) is reflected to become right-hand circular polarization (RHCP). An incident wave that is reflected twice (or any even number) of times prior to returning to the transceiver, has its handedness preserved. Sharp features such as wires and edges tend to return linear polarization, which can be considered to be a sum of both LHCP and RHCP. These characteristics can be exploited for personnel screening by allowing differentiation of smooth features, such as the body, and sharper features present in many concealed items. Additionally, imaging artifacts due to multipath can be identified and eliminated. Laboratory imaging results have been obtained in the 10-20 GHz frequency range and are presented in this paper.

  20. Microfabrication Techniques for Millimeter Wave Vacuum Electronics

    DTIC Science & Technology

    2015-01-01

    versus frequency of a serpentine wave guide slow-wave circuit. WEDM/SEDM: Wire/Sinker Electrical Discharge Machining. Figure 2. UV-LIGA process...2014. 4. A. M. Cook, et al., “Development of a wideband W- band serpentine waveguide TWT,” IEEE 14th Int’l Vac. Elec. Conf., Paris, France, May 2013.

  1. Millimeter-wave Sensor Image Enhancement

    NASA Technical Reports Server (NTRS)

    Wilson, William J.; Suess, Helmut

    1988-01-01

    Images of an airborne scanning radiometer operating at a frequency of 98 GHz were analyzed. The mm wave images were obtained using the JPL mm wave imaging sensor. The goal was to enhance the information content of these images and make their interpretation easier for human analysis. A visual interpretative approach was used for information extraction from the images. This included application of nonlinear transform techniques for noise reduction and for color, contrast, and edge enhancement. Results of the techniques on selected mm wave images are shown.

  2. Nondestructive millimeter wave imaging and spectroscopy using dielectric focusing probes

    SciTech Connect

    Hejase, Jose A.; Shane, Steven S.; Park, Kyoung Y.; Chahal, Premjeet

    2014-02-18

    A tool for interrogating objects over a wide band of frequencies with subwavelength resolution at small standoff distances (near field region) in the transmission mode using a single source and detector measurement setup in the millimeter wave band is presented. The design utilizes optics like principles for guiding electromagnetic millimeter waves from large cross-sectional areas to considerably smaller sub-wavelength areas. While plano-convex lenses can be used to focus waves to a fine resolution, they usually require a large stand-off distance thus resulting in alignment and spacing issues. The design procedure and simulation analysis of the focusing probes are presented in this study along with experimental verification of performance and imaging and spectroscopy examples. Nondestructive evaluation will find benefit from such an apparatus including biological tissue imaging, electronic package integrity testing, composite dielectric structure evaluation for defects and microfluidic sensing.

  3. Millimeter-wave monolithic passive circuit components

    NASA Astrophysics Data System (ADS)

    Binari, S. C.; Neidert, R. E.; Kelner, G.; Boos, J. B.

    1984-12-01

    Several mm-wave passive circuit elements have been designed, fabricated and tested. The circuit elements were designed in a microstrip format and cover the 75- to 150-GHz frequency range. They consist of a terminated 50-Ohm transmission line, a Wilkinson (1960) splitter, a Lange coupler, and a sum/difference network. The test results on these components demonstrate the feasibility of microstrip circuitry in this region of the mm-wave spectrum.

  4. ACRF Archive User Meeting Summary

    SciTech Connect

    SA Edgerton; RA McCord; DP Kaiser

    2007-10-30

    On October 30, 2007, the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) sponsored an all-day workshop to assess the status of the ACRF Archive. Focus areas included usability of current functions, plans for revised functions, proposals for new functions, and an overarching discussion of new ideas. Although 13 scientists familiar with ACRF and the ARM Program were invited to the workshop, only 10 scientists were available to attend the workshop. ACRF consists of the infrastructure that was developed to support the ARM Program and includes the ACRF Archive (previously called the ARM Archive). The scientists who participated in the meeting ranged from those who used the Archive frequently to those who seldom or never had accessed the Archive. The group was spread across disciplines, i.e. modelers, conservationists, and others from universities and government laboratories. A few of the participants were funded by the ARM Program, but most were not funded currently by ARM. During the past year, several improvements were made to the ACRF Archive to link it with the ARM/ACRF web pages, add a shopping cart feature, and expand on search parameters. Additional modifications have been proposed and prototypes of these proposals were made available for the participants. The participants were given several exercises to do before the meeting, and their feedback was requested to help identify potential problems and shortcomings with the existing structure and to recommend improvements.

  5. Millimeter-wave/THz FMCW radar techniques for sensing applications

    NASA Astrophysics Data System (ADS)

    Mirando, D. Amal; Higgins, Michael D.; Wang, Fenggui; Petkie, Douglas T.

    2016-10-01

    Millimeter-wave and terahertz continuous-wave radar systems have been used to measure physiological signatures for biometric applications and for a variety of non-destructive evaluation applications, such as the detection of defects in materials. Sensing strategies for the simplest homodyne systems, such as a Michelson Interferometer, can be enhanced by using Frequency Modulated Continuous Wave (FMCW) techniques. This allows multiple objects or surfaces to be range resolved while monitoring the phase of the signal in a particular range bin. We will discuss the latest developments in several studies aimed at demonstrating how FMCW techniques can enhance mmW/THz sensing applications.

  6. High performance millimeter-wave microstrip circulators and isolators

    NASA Technical Reports Server (NTRS)

    Shih, Ming; Pan, J. J.

    1990-01-01

    Millimeter wave systems, phased array antennas, and high performance components all require wideband circulators (and isolators) to perform diplexing and switching, to improve isolation and Voltage Standing Wave Ratio (VSWR), and to construct IMPATT diode reflection amplifiers. Presently, most of the millimeter-wave circulators and isolators are available in the configurations of waveguide or stripline, both of which suffer from the shortcomings of bulky size/weight, narrow bandwidth, and poor compatibility with monolithic millimeter-wave integrated circuits (MMIC). MMW microstrip circulators/isolators can eliminate or improve these shortcomings. Stub-tuned microstrip circulator configuration were developed utilizing the electromagnetic fields perturbation technique, the adhesion problems of microstrip metallization on new ferrite substrate were overcome, the fabrication, assembly, packaging techniques were improved, and then successfully designed, fabricated a Ka band circulator which has isolation and return loss of greater than 16dB, insertion loss less than 0.7dB. To assess the steady and reliable performance of the circulator, a temperature cycling test was done over the range of -20 to +50 C for 3 continuous cycles and found no significant impact or variation of circulator performance.

  7. High performance millimeter-wave microstrip circulators and isolators

    NASA Astrophysics Data System (ADS)

    Shih, Ming; Pan, J. J.

    1990-02-01

    Millimeter wave systems, phased array antennas, and high performance components all require wideband circulators (and isolators) to perform diplexing and switching, to improve isolation and Voltage Standing Wave Ratio (VSWR), and to construct IMPATT diode reflection amplifiers. Presently, most of the millimeter-wave circulators and isolators are available in the configurations of waveguide or stripline, both of which suffer from the shortcomings of bulky size/weight, narrow bandwidth, and poor compatibility with monolithic millimeter-wave integrated circuits (MMIC). MMW microstrip circulators/isolators can eliminate or improve these shortcomings. Stub-tuned microstrip circulator configuration were developed utilizing the electromagnetic fields perturbation technique, the adhesion problems of microstrip metallization on new ferrite substrate were overcome, the fabrication, assembly, packaging techniques were improved, and then successfully designed, fabricated a Ka band circulator which has isolation and return loss of greater than 16dB, insertion loss less than 0.7dB. To assess the steady and reliable performance of the circulator, a temperature cycling test was done over the range of -20 to +50 C for 3 continuous cycles and found no significant impact or variation of circulator performance.

  8. Millimeter-wave high-resolution holographic surveillance system

    NASA Astrophysics Data System (ADS)

    McMakin, Douglas L.; Sheen, David M.; Collins, H. D.; Hall, Thomas E.; Smith, Russell R.

    1994-03-01

    A prototype millimeter wave holographic surveillance system has been developed and demonstrated at the Pacific Northwest Laboratory (PNL). The prototype millimeter wave holographic surveillance system developed at PNL consists of a sequentially switched 2 X 64 element array coupled to a 35 GHz bi-static transceiver. The sequentially switched array of antennas can be used to obtain the holographic data at high speed by electronically sequencing the antennas along one dimension and performing a mechanical scan along the other dimension. A 1D mechanical scan can be performed in about one second. The prototype system scans an aperture of 0.75 by 2.05 m. This system has been demonstrated and images have been obtained on volunteers at Sea-Tac International airport in Seattle, Washington.

  9. Millimeter-wave generation with spiraling electron beams

    NASA Technical Reports Server (NTRS)

    Kulke, B.

    1971-01-01

    The feasibility of using the interaction between a thin, solid, spiraling electron beam of 10 to 20 kV energy and a microwave cavity to generate watts of CW millimeter-wave power was investigated. Experimental results are given for several prototype devices operating at 9.4 GHz and at 94 GHz. Power outputs of 5 W, and electronic efficiencies near 3%, were obtained at X band, and moderate gain was obtained at 94 GHz. The small-signal theory gives a good fit to the X-band data, and the device behavior at 94 GHz is as expected from the given beam characteristics. The performance is limited chiefly by the velocity spread in the spiraling electron beam, and once this can be brought under control, high-power generation of millimeter waves appears quite feasible with this type of device.

  10. Micromachined room-temperature microbolometers for millimeter-wave detection

    NASA Astrophysics Data System (ADS)

    Rahman, Arifur; de Lange, Gert; Hu, Qing

    1996-04-01

    We have combined silicon micromachining technology with planar circuits to fabricate room-temperature niobium microbolometers for millimeter-wave detection. In this type of detector, a thin niobium film, with a dimension much smaller than the wavelength and fabricated on a 1 μm thick Si3N4 membrane, acts both as a radiation absorber and temperature sensor. Incident radiation is coupled into the microbolometer by a 0.37λ dipole antenna of center frequency 95 GHz with a 3 dB bandwidth of 15%, which is impedance matched with the Nb film. An electrical noise equivalent power (NEP) of 4.5×10-10 W/√Hz has been achieved. This is comparable to the best commercial room-temperature millimeter-wave detectors.

  11. RF to millimeter wave integration and module technologies

    NASA Astrophysics Data System (ADS)

    Vähä-Heikkilä, T.

    2015-04-01

    Radio Frequency (RF) consumer applications have boosted silicon integrated circuits (IC) and corresponding technologies. More and more functions are integrated to ICs and their performance is also increasing. However, RF front-end modules with filters and switches as well as antennas still need other way of integration. This paper focuses to RF front-end module and antenna developments as well as to the integration of millimeter wave radios. VTT Technical Research Centre of Finland has developed both Low Temperature Co-fired Ceramics (LTCC) and Integrated Passive Devices (IPD) integration platforms for RF and millimeter wave integrated modules. In addition to in-house technologies, VTT is using module and component technologies from other commercial sources.

  12. Millimeter-wave experiments for cometary space missions

    NASA Technical Reports Server (NTRS)

    Hobbs, R. W.; Brandt, J. C.; Maran, S. P.; Hollis, J. M.

    1981-01-01

    Predicted brightness temperatures, computed by means of radiative transfer techniques adapted from the modeling of terrestrial ice and snow fields, are given for cometary nucleus models consisting of homogeneous layers of water ice and refractory grain mixtures presented as functions of wavelength. The computed millimeter-wave spectra are sensitive to the values of such physically significant nucleus parameters as (1) crust thickness, (2) subsurface temperature gradient, and (3) sublimating surface boundary temperature. Although antenna beam dilution is a major obstacle for ground-based molecular spectral line radio observations of comets, a millimeter-wave radiometer in the vicinity of the comet would be immune to this effect and able to make observations of several candidate parent molecules in the gas phase.

  13. Interface Structures for Millimeter-Wave Circuits.

    DTIC Science & Technology

    1984-09-25

    designed to be implemented either in a metal waveguide or in a printed transmission line. Therefore, a good transition between the dielectric waveguide ...WODlCniueo eea ide If necesarwy and Identify by block nmber) Dielectric waveguides , quasi-optical structures, printed transmission lines, Gain devices...wave phenomena and dielectric waveguides . A list of publications is included. DD W~S13 ENIOR OF I OV 5,ISOBSOLETE UCASFE SECUITY CLASSIFICATION OF THIS

  14. Millimeter-wave imaging of composite materials

    SciTech Connect

    Gopalsami, N.; Bakhtiari, S.; Dieckman, S.L.; Raptis, A.C.; Lepper, M.J.

    1993-09-01

    This work addresses the application and evaluates the potential of mm-wave imaging in the W-band (75-110 GHz) using samples of low-loss dielectric and composite materials with artificial defects. The initial focus is on the measurement of amplitude changes in the back scattered and forward-scattered fields. The c-scan system employs a focused beam antenna to provide spatial resolution of about one wavelength. A plane-wave model is used to calculate the effective reflection (or transmission) coefficient of multilayer test sample geometry. Theoretical analysis is used to optimize the measurement frequency for higher image contrast and to interpret the experimental results. Both reflection and transmission images, based on back scattered and forward-scattered powers, were made with Plexiglas and Kevlar/epoxy samples containing artificially introduced defects such as subsurface voids and disbonds. The results clearly indicate that mm-wave imaging has high potential for non-contact interrogation of low-loss materials.

  15. Light-Millimeter Wave Interactions in Semiconductor Devices

    DTIC Science & Technology

    1990-01-30

    bias will result in better transient performance [4-91. can be applied to rather high bias voltage. When examining the traditional techniques of...millimeter wave antenna for nents. imaging array applications." Electromagentics , vol. 3. pp. 209-215. 1983. 151 C. P. Wen. "Coplanar waveguidc: A...heterodyne detection," Opt. Lett., vol. 8, pp. 419-421, 1983 21. S. Ben . E, Biglieri and V. Castellri, " Digital Transmission Theory," pp. 211-220, Addison

  16. Millimeter-wave sensing of the environment: A bibliographic survey

    NASA Technical Reports Server (NTRS)

    Schneider, E.; Epstein, E. E.

    1981-01-01

    This literature survey was conducted to examine the field of millimeter wave remote sensing of the environment and collect all relevant observations made in the atmospheric windows near 90, 140, and 230 GHz of ocean, terrain, man-made features, and the atmosphere. Over 170 articles and reports were examined; bibliographic references are provided for all and abstracts are quoted when available. Selected highlights were extracted from the pertinent articles.

  17. Characterization of Composite Materials Using Millimeter-Wave Techniques (Preprint)

    DTIC Science & Technology

    2011-11-01

    focused on to the sample via an off axis parabolic mirror (f/1.5), which provided high spatial resolution (diffraction limited) and a short depth of...AFRL-RX-WP-TP-2011-4380 CHARACTERIZATION OF COMPOSITE MATERIALS USING MILLIMETER-WAVE TECHNIQUES (PREPRINT) A.T. Cooney Ceramics Branch...Metals, Ceramics & Nondestructive Evaluation Division L. Owens, M. Bischoff, D.T. Petkie, and J.A. Deibel Wright State University

  18. Circulators for microwave and millimeter-wave integrated circuits

    NASA Astrophysics Data System (ADS)

    Schloemann, Ernst F.

    1988-02-01

    The requirements for circulators for use in combination with microwave and millimeter-wave integrated circuits are reviewed, with special emphasis on modules for phased-array antennas. Recent advances in broadbanding and in miniaturization are summarized. Novel types of circulators that are fabricated by attaching a ferrite disc and a suitable coupling structure to the surface of a dielectric or semiconductor substrate ('quasi-monolithic' integration) are described. Methods for achieving complete monolithic integration are also discussed.

  19. Millimeter-wave structures and drivers for future linear colliders

    SciTech Connect

    Nassiri, A.; Kang, Y.W.; Song, J.J.

    2000-07-24

    There is a growing interest in the development of very high gradient ({ge} GeV/meter) accelerating structures and millimeter-wave power sources. The need for very high gradient structures to be operated in W-band or at higher frequencies poses great technical challenges and demands innovations in rf science and technology to reach this goal. Requirements for microstructure fabrication and power sources based on deep x-ray lithography techniques are examined.

  20. Near millimeter wave characterization of dual mode materials

    NASA Astrophysics Data System (ADS)

    Stead, Michael; Simonis, George

    1989-05-01

    Nine materials which have application to both the millimeter and IR wavelength regions have been analyzed, and their indices of refraction and absorption coefficients have been determined in the 4-18/cm range. The lowest loss materials are found to be ALON and sapphire, and the highest loss samples to be ZnS and ZnSe. The mm-wave indices are all shown to be higher than their corresponding IR indices.

  1. Evaluation of High Permittivity Glass Ceramics for Millimeter Wave Applications.

    DTIC Science & Technology

    2014-09-26

    Millimeter Wave IfS ASTNACT (enew em reverse e* if n aesee7 wd Identify by block namber) - The crystallization and dielectric properties of strontium ...34Dielectric Properties of Strontium Titanate Glass Ceramics," is included in Appendix 3. ’- 5.0 PARTICIPATING SCIENTIFIC PERSONNEL Work on the contract was...OH, U.S.A Abstract Strontium titanate glass-ceramics, prepared by the crystallization of strontium titanate-aluminosilicate glasses have been

  2. Enhanced millimeter-wave transmission through subwavelength hole arrays.

    PubMed

    Beruete, M; Sorolla, M; Campillo, I; Dolado, J S; Martín-Moreno, L; Bravo-Abad, J; García-Vidal, F J

    2004-11-01

    We explore, both experimentally and theoretically, the existence in the millimeter-wave range of the phenomenon of extraordinary light transmission through arrays of subwavelength holes. We have measured the transmission spectra of several samples made on aluminum wafers by use of an AB Millimetre quasi-optical vector network analyzer in the wavelength range 4.2-6.5 mm. Clear signals of the existence of resonant light transmission at wavelengths close to the period of the array appear in the spectra.

  3. High power millimeter wave ECRH source needs for fusion program

    SciTech Connect

    Not Available

    1984-06-01

    This document stems from the four-day Gyrotron Symposium held at the US Department of Energy (DOE) Headquarters on June 13-16, 1983, and serves as a position paper for the Office of Fusion Energy, DOE, on high-power millimeter wave source development for Electron Cyclotron Heating (ECH) of plasmas. It describes the fusion program needs for gyrotron as ECH sources, their current status, and desirable development strategies.

  4. System analysis for millimeter-wave communication satellites

    NASA Technical Reports Server (NTRS)

    Holland, L. D.; Hilsen, N. B.; Gallagher, J. J.; Stevens, G.

    1980-01-01

    Research and development needs for millimeter-wave space communication systems are presented. Assumed propagation fade statistics are investigated along with high data rate diversity link and storage. The development of reliable ferrite switches, and high performance receivers and transmitters is discussed, in addition to improved tolerance of dish and lens fabrication for the antennas. The typical cost for using a simplex voice channel via a high capacity 40/50 GHz satellite is presented.

  5. A Three-Frequency Feed for Millimeter-Wave Radiometry

    NASA Technical Reports Server (NTRS)

    Hoppe, Daniel J.; Khayatian, Behrouz; Sosnowski, John B.; Johnson, Alan K.; Bruneau, Peter J.

    2012-01-01

    A three-frequency millimeter-wave feed horn was developed as part of an advanced component technology task that provides components necessary for higher-frequency radiometers to meet the needs of the Surface Water and Ocean Topography (SWOT) mission. The primary objectives of SWOT are to characterize ocean sub-mesoscale processes on 10-km and larger scales in the global oceans, and to measure the global water storage in inland surface water bodies, including rivers, lakes, reservoirs, and wetlands. In this innovation, the feed provides three separate output ports in the 87-to- 97-GHz, 125-to-135-GHz, and 161-to-183- GHz bands; WR10 for the 90-GHz channel, WR8 for the 130-GHz channel, and WR5 for the 170-GHz channel. These ports are in turn connected to individual radiometer channels that will also demonstrate component technology including new PIN-diode switches and noise diodes for internal calibration integrated into each radiometer front end. For this application, a prime focus feed is required with an edge taper of approximately 20 dB at an illumination angle of 40 deg. A single polarization is provided in each band. Preliminary requirements called for a return loss of better than 15 dB, which is achieved across all three bands. Good pattern symmetry is also obtained throughout all three-frequency bands. This three-frequency broadband millimeter-wave feed also minimizes mass and provides a common focal point for all three millimeter-wave bands.

  6. Millimeter wave, high-resolution, holographic surveillance system

    NASA Astrophysics Data System (ADS)

    McMakin, D. L.; Sheen, D. M.; Collins, H. D.; Hall, T. E.; Smith, R. R.; Droppo, J. G., Jr.

    Millimeter wave holographic imaging systems capable of imaging through clothing to detect contraband, metal, plastic, or ceramic weapons may provided a practical solution to personnel inspection needs in mass transportation centers. Traditional inspection systems, such as metal detectors and x-ray imaging systems, have limitations for the detection of concealed weapons. Metal detectors are limited because they cannot detect plastic weapons and x-ray imaging systems are limited in use due to radiological health considerations. A prototype millimeter wave holographic surveillance system has been developed and demonstrated at the Pacific Northwest Laboratory (PNL). The prototype millimeter wave holographic surveillance system developed at PNL consists of a sequentially switched 2 (times) 64 element array coupled to a 35 GHz bi-static transceiver. The sequentially switched array of antennas can be used to obtain the holographic data at high speed by electronically sequencing the antennas along one dimension and performing a mechanical scan along the other dimension. A one-dimensional mechanical scan be be performed in about one second. The prototype system scans an aperture of 0.75 by 2.05. This system has been demonstrated and images have been obtained on volunteers at Sea-Tac International airport in Seattle, Washington.

  7. Identifying explosives using broadband millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Weatherall, James C.; Yam, Kevin; Barber, Jeffrey; Smith, Barry T.; Smith, Peter R.; Greca, Joseph

    2017-05-01

    Millimeter wave imaging is employed in Advanced Technology Imaging (AIT) systems to screen personnel for concealed explosives and weapons. AIT systems deployed in airports auto-detect potential threats by highlighting their location on a generic outline of a person using imaging data collected over a range of frequency. We show how the spectral information from the imaging data can be used to identify the composition of an anomalous object, in particular if it is an explosive material. The discriminative value of the technique was illustrated on military sheet explosive using millimeter-wave reflection data at frequencies 18 - 40 GHz, and commercial explosives using 2 - 18 GHz, but the free-space measurement was limited to a single horn with a large-area sample. This work extends the method to imaging data collected at high resolution with a 18 - 40 GHz imaging system. The identification of explosives is accomplished by extracting the dielectric constant from the free-space, multifrequency data. The reflection coefficient is a function of frequency because of propagation effects associated with the material's complex dielectric constant, which include interference from multiple reflections and energy loss in the sample. The dielectric constant is obtained by numerically fitting the reflection coefficient as a function of frequency to an optical model. In principal, the implementation of this technique in standoff imaging systems would allow threat assessment to be accomplished within the scope of millimeter-wave screening.

  8. Millimeter-wave propagation through a controlled dust environment

    NASA Astrophysics Data System (ADS)

    Wikner, David

    2007-04-01

    A one-week experiment was conducted to determine the millimeter-wave transmission loss due to dust. Transmission data was collected at 35, 94, and 217 GHz through a recirculating dust tunnel. Dust clouds of various densities were measured during the experiment. The millimeter-wave measurements were non-coherent, using transmitting sources on one side of the dust tunnel and antenna/detectors on the other. The hardware was designed to minimize noise and drift. Even so, it was found that the transmission loss across the 1-m dust tunnel at high dust densities was lower than could be measured accurately with the equipment. Therefore, the results given are limited to system noise and represent maximum transmission losses at the various frequencies. The results show losses less than 0.02 and 0.08 dB for 94 and 217 GHz respectively across one meter of dust with density 3000 mg/m 3. The actual losses are lower and a long baseline interferometer will be required to determine the loss values precisely. Despite the limitations of the experiment, the data show that millimeter-wave imager performance will not be significantly impacted by even a very dense dust cloud.

  9. Millimeter-wave photonic downconvertors: theory and demonstrations

    NASA Astrophysics Data System (ADS)

    Logan, Ronald T., Jr.; Gertel, Eitan

    1995-10-01

    In this paper, theoretical and experimental results for wideband photonic downconversion systems operating from microwave frequencies through millimeter-wave frequencies are presented. The system consists of a low phase-noise optical heterodyne local oscillator (LO) generator derived froma two-frequency diode-pumped Nd:YAG laser, a millimeter-wave Mach-Zehnder modulator, and a high-speed photodiode. The sum and difference frequency products between the optical LO and the input RF signal are generated upon photodetection. An analysis of photonic heterodyne downconversion is presented, and preliminary experimental downconversion results at Ka-band are presented that are in good agreement with the theoretical prediction of 6 dB conversion loss. Due to the high degree of correlation between the phase fluctuations of the laser modes, the phase noise is much lower than that of previous heterodyne sources, which were typically too noisy for many applications. The free- running optical LO has measured phase noise better than L(1 kHz) equals -90 dBc/Hz at X-band, limited by the measuring system. Finally, novel microwave and millimeter-wave system architectures with enhanced performance and flexibility are discussed, and compared to conventional downlink systems employing electronic mixers.

  10. Image processing techniques for passive millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Lettington, Alan H.; Gleed, David G.

    1998-08-01

    We present our results on the application of image processing techniques for passive millimeter-wave imaging and discuss possible future trends. Passive millimeter-wave imaging is useful in poor weather such as in fog and cloud. Its spatial resolution, however, can be restricted due to the diffraction limit of the front aperture. Its resolution may be increased using super-resolution techniques but often at the expense of processing time. Linear methods may be implemented in real time but non-linear methods which are required to restore missing spatial frequencies are usually more time consuming. In the present paper we describe fast super-resolution techniques which are potentially capable of being applied in real time. Associated issues such as reducing the influence of noise and improving recognition capability will be discussed. Various techniques have been used to enhance passive millimeter wave images giving excellent results and providing a significant quantifiable increase in spatial resolution. Examples of applying these techniques to imagery will be given.

  11. Millimeter wave, high-resolution, holographic surveillance system

    SciTech Connect

    McMakin, D.L.; Sheen, D.M.; Collins, H.D.; Hall, T.E.; Smith, R.R.; Droppo, J.G. Jr.

    1993-12-01

    Millimeter wave holographic imaging systems capable of imaging through clothing to detect contraband, metal, plastic, or ceramic weapons may provided a practical solution to personnel inspection needs in mass transportation centers. Traditional inspection systems, such as metal detectors and x-ray imaging systems, have limitations for the detection of concealed weapons. metal detectors are limited because they cannot detect plastic weapons and x-ray imaging systems are limited in use due to radiological health considerations. A prototype millimeter wave holographic surveillance system has been developed and demonstrated at the Pacific Northwest Laboratory (PNL). The prototype millimeter wave holographic surveillance system developed at PNL consists of a sequentially switched 2 {times} 64 element array coupled to a 35 GHz bi-static transceiver. The sequentially switched array of antennas can be used to obtain the holographic data at high speed by electonically sequencing the antennas along one dimension and performing a mechanical scan along the other dimension. A one-dimensional mechanical scan be be performed in about one second. The prototype system scans an aperture of 0.75 by 2.05. This system has been demonstrated and images have been obtained on volunteers at Sea-Tac International airport in Seattle, Washington.

  12. Polydimethylsiloxane membranes for millimeter-wave planar ultra flexible antennas

    NASA Astrophysics Data System (ADS)

    Tiercelin, Nicolas; Coquet, Philippe; Sauleau, Ronan; Senez, Vincent; Fujita, Hiroyuki

    2006-11-01

    We present here the use of polydimethylsiloxane (PDMS) membranes as a new soft polymer substrate (ɛr ap 2.67 at 77 GHz) for the realization of ultra-flexible millimeter-wave printed antennas thanks to the extremely low Young's modulus (EPDMS < 2 MPa). Ultimately this peculiar property enables one to design wide-angle mechanically beam-steering antennas and flexible conformal antennas. The experimental characterization of PDMS material in V- and W-bands highlights high loss tangent values (tanδ ap 0.04 at 77 GHz). Thus micromachining techniques have been developed to reduce dielectric losses for antenna applications at millimeter waves. Here the antenna performance is demonstrated in the 60 GHz band by considering a single microstrip patch antenna supported by a PDMS membrane over an air-filled cavity. After a brief description of the design approach using the method of moments (MoM) and the finite-difference time-domain (FDTD) technique, the technological processes are described in detail. The input impedance and radiation patterns of the prototype are in good agreement with numerical simulations. The radiation efficiency of the micromachined antenna is equal to 60% and is in the same order as that obtained with conventional polymer bulk substrates such as Duroids. These results confirm the validity of the new technological process and assembly procedure, and demonstrate that PDMS membranes can be used to realize low-loss planar membrane-supported millimeter-wave printed circuits and radiating structures.

  13. Millimeter wave Diagnostic Capability on TCV

    NASA Astrophysics Data System (ADS)

    Porte, Laurie; Alberti, Stefano; Coda, Stefano; Duval, Basil; Fontana, Matteo; Goodman, Timothy; Molina-Cabrera, Pedro; SPC Team

    2016-10-01

    TCV has a large set of millimetre wave diagnostics. Two 24 channel ECE heterodyne radiometers have been installed. Each has a line of sight perpendicular to the toroidal magnetic field. One radiometer views from the high-field side (HFS) while the second views from the low-field-side (LFS). Each device has two mixers and local oscillators and their associated IF instrumentation and video detection. In addition, a six channel correlation ECE (CECE) radiometer has been installed for measuring electron temperature fluctuations. The CECE radiometer has a high gain antenna that can be rotated in both the toroidal and poloidal planes. All of the radiometers can be attached to a vertical line of sight allowing measurement of ECE signals generated by supra-thermal electrons. A millimetre-wave transmission diagnostic is being commissioned for the measurement of the absorption of the ECRH power. A 300 GHz interferometer has been installed. It is optimised for use at density below 4x1019 m-3. Finally, a short pulse reflectometer is being installed and Doppler backscattering measurements have been made. All of these diagnostic systems will be described and their potential use will be detailed. This work partially funded by the Swiss National Science Foundation.

  14. Millimeter-wave interferometric SAR and polarimetry

    NASA Astrophysics Data System (ADS)

    Boehmsdorff, Stephan; Essen, Helmut; Schimpf, Hartmuf; Wahlen, Alfred

    1998-07-01

    Using synthetic aperture radars with appropriate signal processing algorithms is a recognized technique for remote sensing applications. A wide spectrum of radar frequencies is used and a high degree of sophistication implies polarimetric and further multichannel approaches. Each frequency band used, exhibits special sensitivities to features of the earth's surface or man-made targets. This is mostly due to the coupling of the electromagnetic waves to backscattering geometries which are related to the radarwavelength. A part of the spectrum which has been covered not very intensely is the millimeterwave region. This may be mostly due to the relatively high atmospheric absorption at millimeterwaves which obstructs the use of such sensors for long range applications. On the other hand for military applications IR-imaging sensors are widely used which suffer even more from adverse transmission properties of the atmosphere. Application of multichannel techniques as polarimetry, multifrequency techniques and interferometry are also done with more ease due to compactness of the hardware and simplicity of processing. As there exist no data which would allow to investigate the potential of multifrequency polarimetric and interferometric mmW-SAR the Millimeterwave Experimental Multifrequency Polarimetric High Resolution Interferometric Imaging System was installed into an aircraft C-160 `Transall' to gather respective data over different land scenarios. The off-line evaluation of the radar data starts with off-line track, calibration and reformatting procedures. Afterwards synthetic aperture processing is applied to these data to generate radar images for co- and cross-polarization at 35 GHz and 94 GHz. As already mentioned above, SAR-processing at millimeterwavelengths requires a considerable lower amount of sophistication in comparison with algorithms applied at lower radar-frequencies. This can mainly be attributed to the short aperture length at mm-wave frequencies

  15. Multi-octave metamaterial reflective half-wave plate for millimeter and sub-millimeter wave applications.

    PubMed

    Pisano, Giampaolo; Maffei, Bruno; Ade, Peter A R; de Bernardis, Paolo; de Maagt, Peter; Ellison, Brian; Henry, Manju; Ng, Ming Wah; Schortt, Brian; Tucker, Carole

    2016-12-20

    The quasi-optical modulation of linear polarization at millimeter and sub-millimeter wavelengths can be achieved by using rotating half-wave plates (HWPs) in front of polarization-sensitive detectors. Large operational bandwidths are required when the same device is meant to work simultaneously across different frequency bands. Previous realizations of half-wave plates, ranging from birefringent multi-plates to mesh-based devices, have achieved bandwidths of the order of 100%. Here we present the design and experimental characterization of a reflective HWP able to work across bandwidths of the order of 150%. The working principle of the novel device is completely different from any previous realization, and it is based on the different phase-shift experienced by two orthogonal polarizations reflecting, respectively, off an electric conductor and an artificial magnetic conductor.

  16. Millimeter wave experiment for ATS-F

    NASA Technical Reports Server (NTRS)

    Green, J. S.; Parisky, R. N.; Shapiro, S. S.

    1973-01-01

    A detailed description of spaceborne equipment is provided. The equipment consists of two transmitters radiating signals at 20 and 30 GHz from either U.S. coverage horn antennas or a narrow beam parabolic antenna. Three modes of operation are provided: a continuous wave mode, a multitone mode in which nine spectral lines having 180 MHz separation and spaced symmetrically about each carrier, and a communications mode in which communications signals from the main spacecraft transponder are modulated on the two carriers. Detailed performance attained in the flight/prototype model of the equipment is presented both under laboratory conditions and under environmental extremes. Provisions made for ensuring reliability in space operation are described. Also described the bench test equipment developed for use with the experiment, and a summary of the new technology is included.

  17. 3D Imaging Millimeter Wave Circular Synthetic Aperture Radar

    PubMed Central

    Zhang, Renyuan; Cao, Siyang

    2017-01-01

    In this paper, a new millimeter wave 3D imaging radar is proposed. The user just needs to move the radar along a circular track, and high resolution 3D imaging can be generated. The proposed radar uses the movement of itself to synthesize a large aperture in both the azimuth and elevation directions. It can utilize inverse Radon transform to resolve 3D imaging. To improve the sensing result, the compressed sensing approach is further investigated. The simulation and experimental result further illustrated the design. Because a single transceiver circuit is needed, a light, affordable and high resolution 3D mmWave imaging radar is illustrated in the paper. PMID:28629140

  18. Detecting Extrasolar Planets With Millimeter-Wave Observatories

    NASA Astrophysics Data System (ADS)

    1996-01-01

    Do nearby stars have planetary systems like our own? How do such systems evolve? How common are such systems? Proposed radio observatories operating at millimeter wavelengths could start answering these questions within the next 6-10 years, according to scientists at the National Radio Astronomy Observatory (NRAO). Bryan Butler, Robert Brown, Richard Simon, Al Wootten and Darrel Emerson, all of NRAO, presented their findings today to the American Astronomical Society meeting in San Antonio, TX. Detecting planets circling other stars is a particularly difficult task, and only a few such planets have been discovered so far. In order to answer fundamental questions about planetary systems and their origin, scientists need to find and study many more extrasolar planets. According to the NRAO scientists, millimeter-wavelength observatories could provide valuable information about extrasolar planetary systems at all stages of their evolution. "With instruments planned by 2005, we could detect planets the size of Jupiter around a solar-type star out to a distance of 100 light-years," said Robert Brown, Associate Director of NRAO. "That means," he added, "that we could survey approximately 2,000 stars of different types to learn if they have planets this size." Millimeter waves occupy the portion of the electromagnetic spectrum between radio microwaves and infrared waves. Telescopes for observing at millimeter wavelengths utilize advanced electronic equipment similar to that used in radio telescopes observing at longer wavelengths. Millimeter-wave observatories offer a number of advantages in the search for extrasolar planets. Planned multi-antenna millimeter-wave telescopes can provide much higher resolving power, or ability to see fine detail, than current optical or infrared telescopes. Millimeter-wave observations would not be degraded by interference from the "zodiacal light" reflected by interplanetary dust, either in the extrasolar system or our own solar system

  19. Millimeter-wave and terahertz integrated circuit antennas

    NASA Technical Reports Server (NTRS)

    Rebeiz, Gabriel M.

    1992-01-01

    This paper presents a comprehensive review of integrated circuit antennas suitable for millimeter and terahertz applications. A great deal of research was done on integrated circuit antennas in the last decade and many of the problems associated with electrically thick dielectric substrates, such as substrate modes and poor radiation patterns, have been understood and solved. Several new antennas, such as the integrated horn antenna, the dielectric-filled parabola, the Fresnel plate antenna, the dual-slot antenna, and the log-periodic and spiral antennas on extended hemispherical lenses, have resulted in excellent performance at millimeter-wave frequencies, and are covered in detail in this paper. Also, a review of the efficiency definitions used with planar antennas is given in detail in the appendix.

  20. Millimeter-wave and terahertz integrated circuit antennas

    NASA Technical Reports Server (NTRS)

    Rebeiz, Gabriel M.

    1992-01-01

    This paper presents a comprehensive review of integrated circuit antennas suitable for millimeter and terahertz applications. A great deal of research was done on integrated circuit antennas in the last decade and many of the problems associated with electrically thick dielectric substrates, such as substrate modes and poor radiation patterns, have been understood and solved. Several new antennas, such as the integrated horn antenna, the dielectric-filled parabola, the Fresnel plate antenna, the dual-slot antenna, and the log-periodic and spiral antennas on extended hemispherical lenses, have resulted in excellent performance at millimeter-wave frequencies, and are covered in detail in this paper. Also, a review of the efficiency definitions used with planar antennas is given in detail in the appendix.

  1. Millimeter wave satellite concepts. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Hilsen, N. B.; Holland, L. D.; Wallace, R. W.; Kelly, D. L.; Thomas, R. E.; Gallagher, J. J.; Vogler, F. H.

    1979-01-01

    The objectives of the program were: (1) development of methodology based on the technical requirements of potential services that might be assigned to millimeter wave bands for identifying the viable and appropriate technologies for future NASA millimeter research and development programs, and (2) testing of this methodology with user applications and services. The scope of the program included the entire communications network, both ground and space subsystems. The reports include: (1) cost, weight, and performance models for the subsystems, (2) conceptual design for point-to-point and broadcast communications satellites, (3) analytic relationships between subsystem parameters and an overall link performance, (4) baseline conceptual systems, (5) sensitivity studies, (6) model adjustment analyses, (7) identification of critical technologies and their risks, (8) brief R&D program scenarios for the technologies judged to be moderate or extensive risks.

  2. Integrated focal plane arrays for millimeter-wave astronomy

    NASA Astrophysics Data System (ADS)

    Bock, James J.; Goldin, Alexey; Hunt, Cynthia; Lange, Andrew E.; Leduc, Henry G.; Day, Peter K.; Vayonakis, Anastasios; Zmuidzinas, Jonas

    2002-02-01

    We are developing focal plane arrays of bolometric detectors for sub-millimeter and millimeter-wave astrophysics. We propose a flexible array architecture using arrays of slot antennae coupled via low-loss superconducting Nb transmission line to microstrip filters and antenna-coupled bolometers. By combining imaging and filtering functions with transmission line, we are able to realize unique structures such as a multi-band polarimeter and a planar, dispersive spectrometer. Micro-strip bolometers have significantly smaller active volume than standard detectors with extended absorbers, and can realize higher sensitivity and speed of response. The integrated array has natural immunity to stray radiation or spectral leaks, and minimizes the suspended mass operating at 0.1-0.3 K. We also discuss future space-borne spectroscopy and polarimetry applications. .

  3. Target contrast considerations in millimeter wave radiometry for airborne navigation

    NASA Technical Reports Server (NTRS)

    Mayer, A.

    1971-01-01

    Target signal requirements for aircraft navigation systems that use radiometric receivers which map thermally emitted power radiated by terrain or power radiated by ground-based beacons are discussed. For selected millimeter wavelength bands, microwaves suffer relatively little degradation by absorption or scattering on passage through the atmosphere, despite extreme weather variations. Interest centers on 8-millimeter waves because of component availability, portability (small size), high image resolution, and all-weather capability at this wavelength. The idea of radiometric airborne navigation is introduced. Elements of radiometry, terrain radiation, and atmospheric transmission characteristics are reviewed. Data pertaining to these elements at 8 mm wavelength are collected. Calculation of radiometric contrasts is discussed for some simple models of terrain targets.

  4. Interpreting millimeter-wave radiances over tropical convective clouds

    NASA Astrophysics Data System (ADS)

    Haddad, Z. S.; Sawaya, R. C.; Kacimi, S.; Sy, O. O.; Turk, F. J.; Steward, J.

    2017-02-01

    Attempts to interpret the measurements of millimeter-wave radiometers over tropical storms must overcome the difficulty of modeling the scattering signatures of hydrometeors at these frequencies. Most approaches to date try to retrieve surface precipitation, to which the observations are not directly sensitive. In fact, millimeter wavelengths are most sensitive to the scattering from solid hydrometeors within the upper levels of the cloud. Millimeter-wavelength radiometers have a definite advantage over the lower frequency radiometers in that they have finer spatial resolution to resolve deep convection. Preliminary analyses summarized here indicate that the measurements are indeed sensitive to the depth and intensity of convection. The challenge is to derive a robust approach to make quantitative estimates of the characteristics of the convection directly from the observations, and conversely to derive a robust forward representation of the dependence of the radiances on the underlying moisture fields, to enable effective data assimilation. This is accomplished using a two-step semiempirical approach: first, nearly simultaneous coincident observations by millimeter-wave radiometers and orbiting atmospheric profiling radars are used to enforce unbiased consistency between modeled brightness temperatures and radar and radiometer observations; second, the departure from the first-step mean empirical relations are explained in terms of the moisture variables, using cloud-resolving simulations with different microphysical schemes, including an original microphysical representation that proves to be more consistent with remote sensing observations than existing schemes. The results are a retrieval approach and a forward representation that are unbiased by construction, with uncertainties quantified by the corresponding conditional variances.

  5. Design and development of a multifunction millimeter wave sensor

    NASA Astrophysics Data System (ADS)

    Nadimi, Sayyid Abdolmajid

    1998-11-01

    The millimeter-wave (MMW) spectrum (30-300 GHz) offers a unique combination of features that are advantageous when retrieving information about the environment. Due to small wavelengths involved, physically small antennas may be used to obtain very high gains (>50 dB) and resulting high spatial resolutions. Moreover, some features have scattering and emission behaviors that are more sensitive at MMW wavelengths than at microwave wavelengths. Examples include, water vapor (H2O). fog, haze, clouds, ozone (O 3) molecules, and chlorine monoxide (ClO) have rotational spectra in this region. The 75-110 GHz (W-band) atmospheric window is relatively quiet, and it can supply spectral information that can be useful in identifying and quantifying pollutants. Information such as the size and concentration of particulate pollutants can be obtained using radar techniques at W-band. Although there have been some activities at millimeter wave frequencies over very narrow bandwidths, there is a great need for wider bandwidth instruments for studying scattering and emission behaviors. To address this need and provide a versatile system for laboratory studies of electromagnetic phenomena at millimeter-wave frequencies, a multifunctionmillimeter- wave sensor has been designed and developed. This instrument is an active/passive wide band sensor operating in the 75-110 GHz region of the millimeter wave spectrum in four primary modes: (1)As a spectrometer measuring absorption over the entire 75-110 GHz region. (2)As a radiometer measuring blackbody emissions over the entire 75-110 GHz region. (3)As a pulse radar over a 500 MHz bandwidth centered around 93.1 GHz with a peak power of 200 mW. (4)As a step frequency radar when used in combination with a network analyzer over selected 9 GHz bandwidth segments (75-84, 84-93, 93-102, and 102-110) of the 75-110 GHz region. Measurements were performed on two volume fraction (15% and 20%) dense random media targets using this system. The results

  6. Advanced millimeter-wave security portal imaging techniques

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Bernacki, Bruce E.; McMakin, Douglas L.

    2012-03-01

    Millimeter-wave (mm-wave) imaging is rapidly gaining acceptance as a security tool to augment conventional metal detectors and baggage x-ray systems for passenger screening at airports and other secured facilities. This acceptance indicates that the technology has matured; however, many potential improvements can yet be realized. The authors have developed a number of techniques over the last several years including novel image reconstruction and display techniques, polarimetric imaging techniques, array switching schemes, and high-frequency high-bandwidth techniques. All of these may improve the performance of new systems; however, some of these techniques will increase the cost and complexity of the mm-wave security portal imaging systems. Reducing this cost may require the development of novel array designs. In particular, RF photonic methods may provide new solutions to the design and development of the sequentially switched linear mm-wave arrays that are the key element in the mm-wave portal imaging systems. Highfrequency, high-bandwidth designs are difficult to achieve with conventional mm-wave electronic devices, and RF photonic devices may be a practical alternative. In this paper, the mm-wave imaging techniques developed at PNNL are reviewed and the potential for implementing RF photonic mm-wave array designs is explored.

  7. Millimeter Wave Moisture Sounder Feasibility Study: The Effect of Cloud and Precipitation on Moisture Retrievals.

    DTIC Science & Technology

    1985-03-08

    D-A162 231 MILLIMETER WAVE MOISTURE SOUNDER FEASIBILITY STUDY- THE i/1 EFFECT OF CLOUD A (U) ATMOSPHERIC AND ENVIRONMENTAL RESEARCH INC CAMBRIDGE MA...34 ,,; - -., ,..-.,- -, ,.. . : .,,- ,.. ,- - - , . .. .-. ,=, .-,o.. .- .-,o ,-N . ,.-,."...,- ,,, .. .,..; .. ,., .:°B,.. ’ AFGL-TR-85-0040 MILLIMETER WAVE MOISTURE SOUNDER FEASIBILITY STUDY: THE EFFECT OF...REPORT A PERIOD COVERED Millimeter Wave Moisture Sounder Feasibility Final Report Study: The Effect of Cloud and Precipitation 8 Aug 1984-7 Feb 1985 on

  8. Laminated metamaterial flat lens at millimeter-wave frequencies.

    PubMed

    Kitayama, Daisuke; Yaita, Makoto; Song, Ho-Jin

    2015-09-07

    A flat and thin shape is obviously advantageous not only in terms of reducing the volume of a device, but also in handling and using it. Particularly, laminating or stacking flat devices is an intuitive and straightforward way of tailoring performance and functions. Here, we experimentally demonstrated a laminated flat lens for millimeter-wave frequencies that is based on split-ring resonators (SRRs) composed of multiple layers with different and/or identical index profiles and that exhibits characteristics that are linear combinations of those of the individual lenses. Since the characteristics of the lenses of each layer are preserved regardless of the neighbouring layers, the desired functionalities can be easily implemented simply by laminating elementary lenses designed already. When we laminated two lenses designed for bending or focusing incoming waves at 120 GHz, we clearly observed that the outgoing waves collimated and bended as desired.

  9. On the mechanisms of interaction of low-intensity millimeter waves with biological objects

    NASA Astrophysics Data System (ADS)

    Betskii, O. V.

    1994-01-01

    The interaction of low-intensity millimeter-band electromagnetic waves with biological objects is examined. These waves are widely used in medical practice as a means of physiotherapy for the treatment of various human disorders. Principal attention is given to the mechanisms through which millimeter waves act on the human organism.

  10. On the mechanisms of interaction of low-intensity millimeter waves with biological objects

    SciTech Connect

    Betskii, O.V.

    1994-07-01

    The interaction of low-intensity millimeter-band electromagnetic waves with biological objects is examined. These waves are widely used in medical practice as a means of physiotherapy for the treatment of various human disorders. Principal attention is given to the mechanisms through which millimeter waves act on the human organism.

  11. Investigation of the Millimeter-Wave Plasma Assisted CVD Reactor

    SciTech Connect

    Vikharev, A.; Gorbachev, A.; Kozlov, A.; Litvak, A.; Bykov, Yu.; Caplan, M.

    2006-01-03

    A polycrystalline diamond grown by the chemical vapor deposition (CVD) technique is recognized as a unique material for high power electronic devices owing to unrivaled combination of properties such as ultra-low microwave absorption, high thermal conductivity, high mechanical strength and chemical stability. Microwave vacuum windows for modern high power sources and transmission lines operating at the megawatt power level require high quality diamond disks with a diameter of several centimeters and a thickness of a few millimeters. The microwave plasma-assisted CVD technique exploited today to produce such disks has low deposition rate, which limits the availability of large size diamond disk windows. High-electron-density plasma generated by the millimeter-wave power was suggested for enhanced-growth-rate CVD. In this paper a general description of the 30 GHz gyrotron-based facility is presented. The output radiation of the gyrotron is converted into four wave-beams. Free localized plasma in the shape of a disk with diameter much larger than the wavelength of the radiation is formed in the intersection area of the wave-beams. The results of investigation of the plasma parameters, as well as the first results of diamond film deposition are presented. The prospects for commercially producing vacuum window diamond disks for high power microwave devices at much lower costs and processing times than currently available are outlined.

  12. Effects of millimeter waves on ionic currents of Lymnaea neurons.

    PubMed

    Alekseev, S I; Ziskin, M C

    1999-01-01

    The effects of mm-waves 60.22-62.22 GHz and 75 GHz on A-type K+ currents and the effects of 61.22 GHz on Ca2+ currents of Lymnaea neurons were investigated using a whole-cell voltage-clamp technique. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates at the waveguide outlet, inserted into physiological solution, were in the range of 0-2400 W/kg. Millimeter wave irradiation increased the peak amplitudes, activation rates, and inactivation rates of both ion currents. The changes in A-type K+ current were not dependent on the irradiation frequency. It was shown that the changes in the amplitudes and kinetics of both currents resulted from the temperature rise produced by irradiation. No additional effects of irradiation on A-type K+ current other than thermal were found when tested at the phase transition temperature or in the presence of ethanol. Ethanol reduced the thermal effect of irradiation. Millimeter waves had no effect on the steady-state activation and inactivation curves, suggesting that the membrane surface charge and binding of calcium ions to the membrane in the area of channel locations did not change.

  13. Investigation of the Millimeter-Wave Plasma Assisted CVD Reactor

    SciTech Connect

    Vikharev, A; Gorbachev, A; Kozlov, A; Litvak, A; Bykov, Y; Caplan, M

    2005-07-21

    A polycrystalline diamond grown by the chemical vapor deposition (CVD) technique is recognized as a unique material for high power electronic devices owing to unrivaled combination of properties such as ultra-low microwave absorption, high thermal conductivity, high mechanical strength and chemical stability. Microwave vacuum windows for modern high power sources and transmission lines operating at the megawatt power level require high quality diamond disks with a diameter of several centimeters and a thickness of a few millimeters. The microwave plasma-assisted CVD technique exploited today to produce such disks has low deposition rate, which limits the availability of large size diamond disk windows. High-electron-density plasma generated by the millimeter-wave power was suggested for enhanced-growth-rate CVD. In this paper a general description of the 30 GHz gyrotron-based facility is presented. The output radiation of the gyrotron is converted into four wave-beams. Free localized plasma in the shape of a disk with diameter much larger than the wavelength of the radiation is formed in the intersection area of the wave-beams. The results of investigation of the plasma parameters, as well as the first results of diamond film deposition are presented. The prospects for commercially producing vacuum window diamond disks for high power microwave devices at much lower costs and processing times than currently available are outlined.

  14. The influence of polarization on millimeter wave propagation through rain

    NASA Technical Reports Server (NTRS)

    Bostian, C. W.; Stutzman, W. L.; Wiley, P. H.; Marshall, R. E.

    1974-01-01

    The limitations which precipitation depolarization will place on future millimeter wave earth-satellite communications systems employing orthogonal-polarization frequency sharing was studied and the possibility of improving the fade resistance of such systems either through polarization diversity operation or by the choice of the polarization(s) least subject to attenuation was examined. Efforts were confined largely to ground-based communications systems investigated during a twenty-seven month period. Plans to extend the theoretical results to satellite systems are discussed.

  15. Millimeter and Submillimeter-Wave Integrated Horn Antenna Schottky Receivers.

    NASA Astrophysics Data System (ADS)

    Ali-Ahmad, Walid Youssef

    1993-01-01

    Fundamental Schottky-diode mixers are currently used in most millimeter-wave receivers above 100GHz. The mixers use either a whisker-contacted diode or a planar Schottky diode suspended in a machined waveguide with an appropriate RF matching network. However, waveguide mounts are very expensive to machine for frequencies above 200GHz. Also, the whisker-contacted structure is not compatible with integrated mixers which represent the leading technology used for millimeter- and submillimeter-wave applications such as plasma diagnostics imaging arrays, radiometers, and anti-collision radars. In this work, a novel quasi-integrated horn antenna has been used for the receiver antenna. This antenna has a high gain and a high Gaussian coupling efficiency (97%), similar to machined scalar feed horns, but with the advantage of being easily fabricated up to at least 1.5THz. The quasi-integrated horn antenna is based on the integrated horn antenna structure. The integrated horn antenna consists of a pyramidal cavity with a 70^circ flare angle etched anisotropically in silicon. The cavity focuses the incoming energy on dipole-probe suspended on a membrane inside the horn. The integrated horn antenna does not suffer from dielectric losses or substrate mode losses since the feeding dipole antenna is integrated on a very thin dielectric layer. The mixer circuit, along with the feed dipole, are both integrated on the membrane wafer. The mixer diode is the University of Virginia surface channel planar diode which has a low parasitic capacitance. The diode is epoxied directly at the dipole apex without the need for an RF matching network, and with no mixer tuning required. At 92GHz,the DSB antenna-mixer conversion loss and noise temperature are 5.5dB and 770K, respectively. This represents the best reported results to this date for a quasi-optical mixer with a planar diode, at room temperature. At 335GHz, the DSB antenna-mixer noise temperature is 1750K and it is within 1dB of the

  16. Millimeter-Wave Power-Combining with Radiating Oscillator Arrays.

    NASA Astrophysics Data System (ADS)

    York, Robert Armstrong

    The next generation of communications and radar systems will soon begin to exploit the millimeter-wave portion of the electromagnetic spectrum. Such systems will require a high-power source of millimeter-wave energy, ideally small, lightweight, highly efficient, and failure -proof over a span of decades. Circuits using semiconductor devices have proved useful for this purpose at lower frequencies, but unfortunately the power generating capacity of solid -state devices diminishes quickly as frequencies approach 100 GHz. This has forced designers to use bulky, inefficient, and unreliable (but high-power) vacuum-tube sources. Combining the power produced by a large number of individual solid-state devices has been suggested as a means of overcoming the inherent limitations of millimeter -wave devices. In order to compete with vacuum-tube sources, power-combiners would require up to 1000 devices, presenting a difficult engineering challenge. This thesis introduces one possible solution to this problem. The proposed concept uses arrays of millimeter-wave oscillators, where each oscillator contains one or more active devices in a planar radiating structure. The oscillators are weakly coupled to synchronize frequency and phase relationships, and the power produced by each oscillator is radiatively combined in free-space, which gives rise to very high combining efficiencies. The array concept has been demonstrated at microwave frequencies using both Gunn and MESFET devices in a 4 x 4 patch antenna configuration. The Gunn array produced 22 Watts Equivalent Radiated Power (ERP), and the MESFET array produced 10 Watts ERP. A new theory has been developed which describes the coupled-oscillator dynamics, and has been shown to accurately predict experimentally observed effects. In addition to strict CW power-combining, a new mode of operation has been discovered which enables the same arrays to generate high-power pulses of energy. This new effect involves a "mode

  17. Millimeter-wave spectral line radiation from a powerful explosion

    SciTech Connect

    Kotov, Yu. B.; Popov, V. D.; Semenova, T. A.; Fedorov, V. F.

    2012-01-15

    Millimeter-wave spectral line radiation from a powerful air explosion accompanied by neutron, X-ray, and gamma emission is considered. It is shown that the main contribution to the line radiation in the frequency window of air near the wavelength of 2.3 mm is made by nitric oxide molecules. The set of kinetic equations for a partially ionized plasma near the explosion is solved by the Runge-Kutta method. It is shown that the density of nitrogen oxide molecules increases in time to a certain steady-state level. The spectral power of radiation in the NO lines is estimated.

  18. Transmission line for millimeter-wave integrated circuits

    NASA Astrophysics Data System (ADS)

    Komar, G. I.; Shestopalov, V. P.

    The advantages of the miniature wideband slotted mirror line (SML) for millimeter-wave integrated circuits is described. It is shown that the SML has the same order of losses in the mm-range as the stripline in the cm-range. In addition, the SML makes possible the planar design of a wide range of functional components and units, and provides for the complex miniaturization of closed antenna-feed systems in the mm-range, which makes it possible to avoid the use of several types of sections in a single circuit. Forms of cross sections of the SML are presented.

  19. Millimeter-wave/infrared rectenna development at Georgia Tech

    NASA Technical Reports Server (NTRS)

    Gouker, Mark A.

    1989-01-01

    The key design issues of the Millimeter Wave/Infrared (MMW/IR) monolithic rectenna have been resolved. The work at Georgia Tech in the last year has focused on increasing the power received by the physically small MMW rectennas in order to increase the rectification efficiency. The solution to this problem is to place a focusing element on the back side of the substrate. The size of the focusing element can be adjusted to help maintain the optimum input power density not only for different power densities called for in various mission scenarios, but also for the nonuniform power density profile of a narrow EM-beam.

  20. Millimeter-wave Bragg diffraction of microfabricated crystal structures

    NASA Astrophysics Data System (ADS)

    Yuan, C. P.; Lin, S. Y.; Chang, T. H.; Shew, B. Y.

    2011-06-01

    A compact diffraction apparatus is developed with millimeter-wave propagation between two parallel plates. Two types of microfabricated model crystals are individually mounted on a rotatable structure. In contrast to previous work, the experimental results agree well with Bragg's predictions because multiple scattering is minimized in this configuration. Factors that affect the resolution and signal strength, such as the number of scatterers, cylinder radius, and the distance between the detector and the model crystal, are analyzed. The apparatus offers a visually accessible way to teach students about crystal structure as well as scattering and diffraction.

  1. Optical techniques for millimeter-wave detection and imaging

    NASA Astrophysics Data System (ADS)

    Schuetz, Christopher Arnim

    The benefits of imaging using regions of the electromagnetic spectrum outside the visible range have been known for decades. Infrared and radio frequency imaging techniques have achieved great successes in both military and civilian applications. However, there remains a range of the spectrum between these two regimes that remains relatively unexplored. Millimeter waves, or the range of wavelengths between one millimeter and one centimeter, have remained relatively unexplored as an imaging technology, largely due to the lack of sufficiently sensitive, practical detectors for passive imaging in this regime. At these short wavelengths, the diffraction limit imposed by the limited extent of the imaging aperture significantly limits attainable image resolution. Recent developments in semiconductor low-noise amplifiers have demonstrated many desirable applications for such imaging technology, but have, as yet, not been able to demonstrate the economical, small-format imagers necessary to make such imagers practical in most of the conceived applications. In this regard, I present a new approach to millimeter-wave detection based on optical modulation with subsequent carrier suppression. This approach demonstrates promise in achieving the goal of economical, high-resolution imagers with sufficient sensitivity for passive millimeter-wave imaging. In this thesis, I explain the operational requirements of such detectors, provide theoretical background for their operation, and describe current experimental results obtained using commercially available components in the 35 GHz. In addition, I describe successful efforts to fabricate modulators with improved modulation bandwidths for detection in the 95 GHz atmospheric window. These demonstration systems have attained sufficient single pixel performance to detect thermal emission with a noise equivalent temperature difference (NETD) approaching 1K/ Hz at both 35 and 95 GHz. The NETDs attained correspond to sub-picowatt noise

  2. Segmented Chirped-Pulse Millimeter-Wave Spectroscopy for Astrochemistry

    NASA Astrophysics Data System (ADS)

    Arenas, Benjamin E.; Steber, Amanda; Gruet, Sébastien; Schnell, Melanie

    2016-06-01

    The ability to detect molecules in the interstellar medium (ISM) is afforded to us by the collaboration of state-of-the-art observations, like from the Atacama Large Millimeter/submillimeter Array (ALMA), and high-resolution laboratory spectra. Here, we present our use of a commercial segmented chirped-pulse Fourier transform millimeter-wave rotational spectrometer to study simple oxygen-containing organic molecules. Our spectrometer operates in the region 75 - 110 GHz, providing an overlap with ALMA's Band 3 and allowing direct comparison of our laboratory spectra with observational data. We have measured rotational spectra of 1,2-propanediol[1, 2, 3] and methyl acetate[4, 5] in this spectral range at room temperature - both have been previously studied in the microwave and millimeter-wave regions. The rotational spectrum of the former in the 3 mm region shows eight different conformers to date. Spectral bandwidth overlap with ALMA Band 3 will allow for easier detection of new chemicals in the ISM. [1] Caminati, W., J. Mol. Spectrosc., 86(1), 193-201, 1981. [2] Lovas, F. J., Plusquellic, D. F., Pate, B. H., Neill, J. T., Muckle, M. T. and Remijan, A. J., J. Mol. Spectrosc., 257(1), 82-93, 2009. [3] Bossa, J. -B., Ordu, M. H., Müller, H. S. P., Lewen, F. and Schlemmer, S., Astron. Astrophys., 570, A12, 2014. [4] Tudorie, M., Kleiner, I., Hougen, J. T., Melandri, S., Sutikdja, L. W. and Stahl, W., J. Mol. Spectrosc., 269, 211-225, 2011. [5] Nguyen, H. V. L., Kleiner, I., Shipman, S. T., Mae, Y., Hirose, K., Hatanaka, S. and Kobayashi, K., J. Mol. Spectrosc., 299, 17-21, 2014.

  3. Immunomodulating action of low intensity millimeter waves on primed neutrophils.

    PubMed

    Safronova, Valentina G; Gabdoulkhakova, A G; Santalov, B F

    2002-12-01

    Comparative investigation of the susceptibility of intact and primed neutrophils of the NMRI strain mice to low intensity millimeter wave (mm wave) irradiation (41.95 GHz) was performed. The specific absorption rate was 0.45 W/kg. Isolated neutrophils were primed by a chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) at a subthreshold concentration of 10 nM for 20 min, and then the cells were activated by 1 microM fMLP. Production of the reactive oxygen species (ROS) was estimated by the luminol dependent chemiluminescence technique. It was found that the preliminary mm wave irradiation of the resting cells at 20 degrees C did not act on the ROS production induced by the chemotactic peptide. The exposure of the primed cells results in a subsequent increase in the fMLP response. Therefore, the primed neutrophils are susceptible to the mm waves. Specific inhibitors of the protein kinases abolished the mm wave effect on the primed cells. The data indicate that protein kinases actively participate in transduction of the mm wave signal to effector molecules involved in neutrophil respiratory burst.

  4. Nonintrusive cryogenic propellant sensing with millimeter-wave/EM beams

    NASA Astrophysics Data System (ADS)

    Osterwalder, J. M.; Nyland, T. W.

    1993-07-01

    In this paper experimental results of cryogenic tankage mass measurements and descriptions of level sensors using optical and millimeter wave signal beams are presented. The discussed results are based on a 100 GHz frequency modulated radar mass sensor. Test results are compared with a similar system which makes use of a laser beam and a frequency modulated microwave subcarrier. In addition the performance of a laser triangulation level sensor is presented which is suitable for normal gravity applications. Performance prediction in terms of the resolution and measurement accuracy are discussed with emphasis on the measurement difficulties encountered while using liquid hydrogen under normal gravity conditions. For a mass sensor the small 11% refractive index change between an empty and a filled tank of hydrogen causes a loss of measurement accuracy by a factor of ten, as compared to a level sensor. This loss is common to all mass propellant sensing systems, including the conventional capacitance probe sensor. Special processing techniques are indicated. Extensions of the presented millimeter wave mass sensor concept for micro and zero gravity cryogenic systems and for other special space related propellant conditions such as slush hydrogen are discussed.

  5. A superconducting tunnel junction receiver for millimeter-wave astronomy

    NASA Technical Reports Server (NTRS)

    Pan, S. K.; Kerr, A. R.

    1986-01-01

    The development and construction of an ultralow noise heterodyne receiver for millimeter wave astronomy is described along with its use for 115.3 GHz Co line observations. The receiver uses a Superconductor-Insulator-Superconductor (SIS) quasiparticle tunnel junction mixer to convert the millimeter wave signal to a microwave intermediate frequency. Experiments aimed at quantitative verification of J. R. Tucker's quantum mixer theory are studied, to see whether it could be used as the basis for the design of a practical receiver. The experimental results were in excellent agreement with the theory, assuming the three frequency approximation. Infinite available gain and negative output resistance were observed for the first time, nonclassical effects which are not seen in conventional diode mixers. Using Tucker's theory, an SIS receiver was then designed and constructed. At 115 GHz, the single sideband receiver noise temperature is 83K, the lowest ever reported in this frequency range. A CO survey toward Cygnus-X region, using this SIS receiver on the Columbia-GISS 4 ft. telescope, is also described.

  6. Reflective measurement of water concentration using millimeter wave illumination

    NASA Astrophysics Data System (ADS)

    Sung, Shijun; Bennett, David; Taylor, Zachary; Bajwa, Neha; Tewari, Priyamvada; Maccabi, Ashkan; Culjat, Martin; Singh, Rahul; Grundfest, Warren

    2011-04-01

    THz and millimeter wave technology have shown the potential to become a valuable medical imaging tool because of its sensitivity to water and safe, non-ionizing photon energy. Using the high dielectric constant of water in these frequency bands, reflectionmode THz sensing systems can be employed to measure water content in a target with high sensitivity. This phenomenology may lead to the development of clinical systems to measure the hydration state of biological targets. Such measurements may be useful in fast and convenient diagnosis of conditions whose symptoms can be characterized by changes in water concentration such as skin burns, dehydration, or chemical exposure. To explore millimeter wave sensitivity to hydration, a reflectometry system is constructed to make water concentration measurements at 100 GHz, and the minimum detectable water concentration difference is measured. This system employs a 100 GHz Gunn diode source and Golay cell detector to perform point reflectivity measurements of a wetted polypropylene towel as it dries on a mass balance. A noise limited, minimum detectable concentration difference of less than 0.5% by mass can be detected in water concentrations ranging from 70% to 80%. This sensitivity is sufficient to detect hydration changes caused by many diseases and pathologies and may be useful in the future as a diagnostic tool for the assessment of burns and other surface pathologies.

  7. Sniper bullet detection by millimeter-wave radar

    NASA Astrophysics Data System (ADS)

    Bernstein, Uri; Lefevre, Russell J.; Mann, John; Avent, Randy K.; Deo, Naresh

    1999-01-01

    Law enforcement and military operations would clearly benefit from a capability to locate snipers by backtracking the sniper's bullet trajectory. Achieving sufficient backtracking accuracy for bullets is a demanding radar design, requiring good measurement accuracy, high update rate, and detection of very low cross-section objects. In addition, reasonable cost is a driving requirement for law enforcement use. These divergent design requirements are addressed in an experimental millimeter-wave focal plane array radar that uses integrated millimeter-wave receiver technology. The radar is being built for DARPA by Technology Service Corporation, with assistance from M.I.T. Lincoln Laboratory and QuinStar Technology. The key element in the radar is a 35-GHz focal plane array receiver. The receiving antenna lens focuses radar signals from a wide field of view onto an array of receivers, each receiver processing a separate element of the field of view. Receiver detections are then combined in a tracking processor. An FM-CW waveform is used to provide high average power, good range resolution, and stationary clutter rejection. TSC will be testing the sniper detection radar, using radar environment simulator technology developed at Lincoln Laboratory. The simulator will retransmit the received signal with the range delay, Doppler shift, and ERP for various simulated bullet trajectories.

  8. Millimeter and terahertz wave absorption in a lossy conducting layer

    NASA Astrophysics Data System (ADS)

    Shen, M. K.; Chiang, W. Y.; Wu, K. L.; Chu, K. R.

    2013-10-01

    Relativistic electronics research in recent years has produced powerful millimeter waves on the MW level, while also extending the frequency range into the terahertz (THz) region and beyond. These developments have opened up new horizons in applications. The current study is motivated by the associated need for high-power absorbers not readily available at such frequencies. Our focus is on effective absorber schemes which can handle high power while also possessing a structural simplicity for easy implementation. In and above the THz region, the electrical conductivity can no longer be treated as a real constant. We begin with a derivation of the field penetration depth applicable to all frequencies. Requirements to meet the intended criteria are then determined from the wave penetration and reflection properties. Design examples in the 1-1000 GHz range are illustrated, which consist of a thin lossy conducting layer on the surface of a pyramidal shaped metal base. It is shown in theory that such structures can function effectively in the millimeter and THz regions.

  9. Fluctuations in millimeter-wave signals propagated through inclement weather

    NASA Astrophysics Data System (ADS)

    Bohlander, Ronald A.; McMillan, Robert W.; Patterson, E. M.; Clifford, Steven F.; Hill, Reginald J.

    1988-05-01

    Results are presented from measurements of the effects of inclement weather on the fluctuations in amplitude and phase of millimeter-wave (MMW) signals propagated through the atmosphere. These measurements were made at frequencies near 116, 140, 173, and 230 GHz at a site near Champaign-Urbana, Illinois, in a community chosen for its exceptional flatness and lack of terrain features that might perturb the atmosphere. It was found that this inclement weather fluctuations are generally smaller than those observed in clear air under sunny conditions, and are also smaller than the corresponding effects observed at visible and near-infrared wavelengths. Typical values of the intensity standard deviation observed (in 20-s intervals) were 1 percent in rain, 0.2 percent in fog, and 1.5-2.5 percent in snow. Typical values of the standard deviation of wavefront angle-of-arrival were 40, 5, 4, and 1 microrad from clear air, snow, rain, and fog, respectively. It was also found that rain has the greatest effect on MMW transmission, causing large, slow changes in received signal strength as a function of rain rate. It should also be noted that rain caused the only observed loss of the propagation link, during a thunderstorm in which the rain rate was as high as 60 mm/h. It is concluded that, in general, millimeter-wave radiation propagates well in adverse weather, with rain causing the major problems observed during this series of measurements.

  10. Application of millimeter-wave radiometry for remote chemical detection.

    SciTech Connect

    Gopalsami, N.; Bakhtiari, S.; Elmer, T. W.; Raptis, A. C.; Nuclear Engineering Division

    2008-03-01

    Passive millimeter-wave systems have been used in the past to remotely map solid targets and to measure low-pressure spectral lines of stratospheric and interstellar gases; however, its application to pressure-broadened spectral line detection of industrial emissions is new. We developed a radiative transfer model to determine feasibility and system requirements for passive millimeter-wave spectral detection of terrestrial gases. We designed and built a Dicke-switched multispectral radiometer in the 146-154-GHz band to detect nitric oxide (NO), a prototypical gas of nuclear fuel processing operations. We first tested the spectral detection capability of the radiometer in the laboratory using a gas cell and then field tested it at the Nevada test site at a distance of 600 m from a stack that released hot plumes of NO and air. With features such as Dicke-switched integration, frequent online calibration, and spectral baseline subtraction, we demonstrated the feasibility of remote detection of terrestrial gases by a ground-based radiometer.

  11. Millimeter and terahertz wave absorption in a lossy conducting layer

    SciTech Connect

    Shen, M. K.; Chiang, W. Y.; Wu, K. L.; Chu, K. R.

    2013-10-15

    Relativistic electronics research in recent years has produced powerful millimeter waves on the MW level, while also extending the frequency range into the terahertz (THz) region and beyond. These developments have opened up new horizons in applications. The current study is motivated by the associated need for high-power absorbers not readily available at such frequencies. Our focus is on effective absorber schemes which can handle high power while also possessing a structural simplicity for easy implementation. In and above the THz region, the electrical conductivity can no longer be treated as a real constant. We begin with a derivation of the field penetration depth applicable to all frequencies. Requirements to meet the intended criteria are then determined from the wave penetration and reflection properties. Design examples in the 1–1000 GHz range are illustrated, which consist of a thin lossy conducting layer on the surface of a pyramidal shaped metal base. It is shown in theory that such structures can function effectively in the millimeter and THz regions.

  12. A millimeter-wave tunneLadder TWT

    NASA Technical Reports Server (NTRS)

    Jacquez, A.; Karp, A.; Wilson, D.; Scott, A.

    1988-01-01

    A millimeter wave traveling wave tube was developed using a dispersive, high impedance forward interaction structure based on a ladder, with non-space harmonic interaction, for a tube with high gain per unit length and high efficiency. The TunneLadder interaction structure combines ladder properties modified to accommodate Pierce gun beam optics in a radially magnetized permanent magnet focusing structure. The development involved the fabrication of chemically milled, shaped ladders diffusion brazed to diamond cubes which are in turn active-diffusion brazed to each ridge of a doubly ridged waveguide. Cold test data are presented, representing the omega-beta and impedance characteristics of the modified ladder circuit. These results were used in small and large signal computer programs to predict TWT gain and efficiency. Actual data from tested tubes verify the predicted performance while providing broader bandwidth than expected.

  13. Art Painting Diagnostic Before Restoration with Terahertz and Millimeter Waves

    NASA Astrophysics Data System (ADS)

    Guillet, Jean-Paul; Roux, M.; Wang, K.; Ma, X.; Fauquet, F.; Balacey, H.; Recur, B.; Darracq, F.; Mounaix, P.

    2017-04-01

    Art painting diagnostic is commonly performed using electromagnetic waves at wavelengths from terahertz to X-ray. These former techniques are essential in conservation and art history research, but they could be also very useful for restoring artwork. While most studies use time domain imaging technique, in this study, a painting has been investigated using both time domain imaging (TDI) and frequency-modulated continuous wave (FMCW) system in the millimeter frequency range. By applying these systems to a painting of the eighteenth century, we detect and analyze the structure of some defects. This study underlines the differences between FMCW and TDI. We present the advantages and disadvantages of each technique on a real artwork.

  14. The Millimeter-Wave Properties of Superconducting Microstrip Lines

    NASA Technical Reports Server (NTRS)

    Vayonakis, A.; Luo, C.; Leduc, H. G.; Schoelkopf, R.; Zmuidzinas, J.

    2002-01-01

    We have developed a novel technique for making high quality measurements of the millimeter-wave properties of superconducting thin-film microstrip transmission lines. Our experimental technique currently covers the 75-100 GHz band. The method is based on standing wave resonances in an open ended transmission line. We obtain information on the phase velocity and loss of the microstrip. Our data for Nb/SiO/Nb lines, taken at 4.2 K and 1.6 K, can be explained by a single set of physical parameters. Our preliminary conclusion is that the loss is dominated by the SiO dielectric, with a temperature-independent loss tangent of 5.3 +/- 0.5 x 10(exp -3) for our samples.

  15. Art Painting Diagnostic Before Restoration with Terahertz and Millimeter Waves

    NASA Astrophysics Data System (ADS)

    Guillet, Jean-Paul; Roux, M.; Wang, K.; Ma, X.; Fauquet, F.; Balacey, H.; Recur, B.; Darracq, F.; Mounaix, P.

    2017-01-01

    Art painting diagnostic is commonly performed using electromagnetic waves at wavelengths from terahertz to X-ray. These former techniques are essential in conservation and art history research, but they could be also very useful for restoring artwork. While most studies use time domain imaging technique, in this study, a painting has been investigated using both time domain imaging (TDI) and frequency-modulated continuous wave (FMCW) system in the millimeter frequency range. By applying these systems to a painting of the eighteenth century, we detect and analyze the structure of some defects. This study underlines the differences between FMCW and TDI. We present the advantages and disadvantages of each technique on a real artwork.

  16. Antenna-coupled microbolometers for passive millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Luukanen, Arttu R.; Vaijaervi, Seppo; Sipila, Heikki

    2000-07-01

    Antenna-coupled microbolometers have demonstrated an adequate sensitivity for mm-wave detection. The detector operating principle is based on a lithographic antenna, which is terminated by a matched resistive bolometer. The incident RF power is dissipated in the bolometer element, and the resulting temperature rise is measured with low noise electronics. In this paper, we summarize the recent development in microbolometer technology for millimeter-wave imaging. The aim is to develop a 20 element linear array of detectors with an optical NEP < 10 (DOT) 10-12/(root)Hz at room temperature. In order to reach good performance, excellent thermal isolation of the bolometer element is required. This can be achieved either by silicon micromachining techniques or by the use of low thermal conductivity substrate materials. For good optical performance, a careful design of the coupling structures is required. The lithographic antenna candidates best suited for array applications is discussed. Also the requirements for integrated quasioptical elements are presented.

  17. Experimental millimeter-wave personal satellite communications system

    NASA Technical Reports Server (NTRS)

    Suzuki, Yoshiaki; Kimura, Shigeru; Shimada, Masaaki; Tanaka, Masato; Takahashi, Yasuhiro

    1991-01-01

    Communications Research Laboratory (CRL) has investigated an advanced millimeter (mm)-wave satellite communications system for personal use. Experiments in mm-wave personal satellite communication are to be conducted for 3 years using Japan's Engineering Test Satellite VI (ETS-VI). This paper describes an experimental mm-wave (43/38 GHz) personal satellite communication system, including an onboard transponder and an earth terminal. The on-board transponder is almost completed, and the ground experiment system is still in the design stage. The transponder employs advanced mm-wave solid state technology. It uses 38 GHz high power solid state amplifiers to accelerate the development of mm-wave solid state devices which are indispensable to personal earth terminals. The transponder consists of a 43 GHz receiver with a built-in low noise amplifier, an IF filter section with very narrow bandwidth to improve the carrier-to-noise power ratio of the weak personal communication signal, and two high power amplifiers using newly developed high power Gallium Arsenide (GaAs) metal-semiconductor field effect transistors (MESFETs).

  18. Experimental millimeter-wave personal satellite communications system

    NASA Technical Reports Server (NTRS)

    Suzuki, Yoshiaki; Kimura, Shigeru; Shimada, Masaaki; Tanaka, Masato; Takahashi, Yasuhiro

    1991-01-01

    Communications Research Laboratory (CRL) has investigated an advanced millimeter (mm)-wave satellite communications system for personal use. Experiments in mm-wave personal satellite communication are to be conducted for 3 years using Japan's Engineering Test Satellite VI (ETS-VI). This paper describes an experimental mm-wave (43/38 GHz) personal satellite communication system, including an onboard transponder and an earth terminal. The on-board transponder is almost completed, and the ground experiment system is still in the design stage. The transponder employs advanced mm-wave solid state technology. It uses 38 GHz high power solid state amplifiers to accelerate the development of mm-wave solid state devices which are indispensable to personal earth terminals. The transponder consists of a 43 GHz receiver with a built-in low noise amplifier, an IF filter section with very narrow bandwidth to improve the carrier-to-noise power ratio of the weak personal communication signal, and two high power amplifiers using newly developed high power Gallium Arsenide (GaAs) metal-semiconductor field effect transistors (MESFETs).

  19. Millimeter-Wave Generation via Plasma Three-Wave Mixing

    DTIC Science & Technology

    1990-03-01

    Gliz radiation are listed below the oscilloscope waveform. 60 I I 16693 12 I 3 HYDROGEN KRYPTON - HELIUM XENON A RGON TIME (100 ns/div) TIME (20 ns/div...Pulses Overlap in Time ........ 48 29 Frequency Scaling with Waveguide Discharge Current is Determined by Observing the mm-wave Output with an Array of...59 37 Output mm-wave Radiation is Strongly Modulated on a Time Scale which is Near the Ion-Plasma Frequency ............................ 60 j

  20. Millimeter Wave Sensor For On-Line Inspection Of Thin Sheet Dielectrics

    DOEpatents

    Bakhtiari, Sasan; Gopalsami, Nachappa; Raptis, Apostolos C.

    1999-03-23

    A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components. A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components.

  1. Modern Microwave and Millimeter-Wave Power Electronics

    NASA Astrophysics Data System (ADS)

    Barker, Robert J.; Luhmann, Neville C.; Booske, John H.; Nusinovich, Gregory S.

    2005-04-01

    A comprehensive study of microwave vacuum electronic devices and their current and future applications While both vacuum and solid-state electronics continue to evolve and provide unique solutions, emerging commercial and military applications that call for higher power and higher frequencies to accommodate massive volumes of transmitted data are the natural domain of vacuum electronics technology. Modern Microwave and Millimeter-Wave Power Electronics provides systems designers, engineers, and researchers-especially those with primarily solid-state training-with a thoroughly up-to-date survey of the rich field of microwave vacuum electronic device (MVED) technology. This book familiarizes the R&D and academic communities with the capabilities and limitations of MVED and highlights the exciting scientific breakthroughs of the past decade that are dramatically increasing the compactness, efficiency, cost-effectiveness, and reliability of this entire class of devices. This comprehensive text explores a wide range of topics: * Traveling-wave tubes, which form the backbone of satellite and airborne communications, as well as of military electronic countermeasures systems * Microfabricated MVEDs and advanced electron beam sources * Klystrons, gyro-amplifiers, and crossed-field devices * "Virtual prototyping" of MVEDs via advanced 3-D computational models * High-Power Microwave (HPM) sources * Next-generation microwave structures and circuits * How to achieve linear amplification * Advanced materials technologies for MVEDs * A Web site appendix providing a step-by-step walk-through of a typical MVED design process Concluding with an in-depth examination of emerging applications and future possibilities for MVEDs, Modern Microwave and Millimeter-Wave Power Electronics ensures that systems designers and engineers understand and utilize the significant potential of this mature, yet continually developing technology. SPECIAL NOTE: All of the editors' royalties realized from

  2. Millimeter wave and terahertz dielectric properties of biological materials

    NASA Astrophysics Data System (ADS)

    Khan, Usman Ansar

    Broadband dielectric properties of materials can be employed to identify, detect, and characterize materials through their unique spectral signatures. In this study, millimeter wave, submillimeter wave, and terahertz dielectric properties of biological substances inclusive of liquids, solids, and powders were obtained using Dispersive Fourier Transform Spectroscopy (DFTS). Two broadband polarizing interferometers were constructed to test materials from 60 GHz to 1.2 THz. This is an extremely difficult portion of the frequency spectrum to obtain a material's dielectric properties since neither optical nor microwave-based techniques provide accurate data. The dielectric characteristics of liquids such as cyclohexane, chlorobenzene, benzene, ethanol, methanol, 1,4 dioxane, and 10% formalin were obtained using the liquid interferometer. Subsequently the solid interferometer was utilized to determine the dielectric properties of human breast tissues, which are fixed and preserved in 10% formalin. This joint collaboration with the Tufts New England Medical Center demonstrated a significant difference between the dielectric response of tumorous and non-tumorous breast tissues across the spectrum. Powders such as anthrax, flour, talc, corn starch, dry milk, and baking soda have been involved in a number of security threats and false alarms around the globe in the last decade. To be able to differentiate hoax attacks and serious security threats, the dielectric properties of common household powders were also examined using the solid interferometer to identify the powders' unique resonance peaks. A new sample preparation kit was designed to test the powder specimens. It was anticipated that millimeter wave and terahertz dielectric characterization will enable one to clearly distinguish one powder from the other; however most of the powders had relatively close dielectric responses and only Talc had a resonance signature recorded at 1.135 THz. Furthermore, due to

  3. Passive front-ends for wideband millimeter wave electronic warfare

    NASA Astrophysics Data System (ADS)

    Jastram, Nathan Joseph

    This thesis presents the analysis, design and measurements of novel passive front ends of interest to millimeter wave electronic warfare systems. However, emerging threats in the millimeter waves (18 GHz and above) has led to a push for new systems capable of addressing these threats. At these frequencies, traditional techniques of design and fabrication are challenging due to small size, limited bandwidth and losses. The use of surface micromachining technology for wideband direction finding with multiple element antenna arrays for electronic support is demonstrated. A wideband tapered slot antenna is first designed and measured as an array element for the subsequent arrays. Both 18--36 GHz and 75--110 GHz amplitude only and amplitude/phase two element direction finding front ends are designed and measured. The design of arrays using Butler matrix and Rotman lens beamformers for greater than two element direction finding over W band and beyond using is also presented. The design of a dual polarized high power capable front end for electronic attack over an 18--45 GHz band is presented. To combine two polarizations into the same radiating aperture, an orthomode transducer (OMT) based upon a new double ridge waveguide cross section is developed. To provide greater flexibility in needed performance characteristics, several different turnstile junction matching sections are tested. A modular horn section is proposed to address flexible and ever changing operational requirements, and is designed for performance criteria such as constant gain, beamwidth, etc. A multi-section branch guide coupler and low loss Rotman lens based upon the proposed cross section are also developed. Prototyping methods for the herein designed millimeter wave electronic warfare front ends are investigated. Specifically, both printed circuit board (PCB) prototyping of micromachined systems and 3D printing of conventionally machined horns are presented. A 4--8 GHz two element array with

  4. Near-field millimeter - wave imaging of nonmetallic materials

    SciTech Connect

    Gopalsami, N.; Bakhtiari, S.; Raptis, A.C.

    1996-12-31

    A near-field millimeter-wave (mm-wave) imaging system has been designed and built in the 94-GHz range for on-line inspection of nonmetallic (dielectric) materials. The imaging system consists of a transceiver block coupled to an antenna that scans the material to be imaged; a reflector plate is placed behind the material. A quadrature IF mixer in the transceiver block enables measurement of in-phase and quadrature-phase components of reflected signals with respect to the transmitted signal. All transceiver components, with the exception of the Gunn-diode oscillator and antenna, were fabricated in uniform blocks and integrated and packaged into a compact unit (12.7 x 10.2 x 2.5 cm). The objective of this work is to test the applicability of a near-field compact mm-wave sensor for on-line inspection of sheetlike materials such as paper, fabrics, and plastics. This paper presents initial near-field mm-wave images of paper and fabric samples containing known artifacts.

  5. Millimeter- and Submillimeter-Wave Remote Sensing Using Small Satellites

    NASA Technical Reports Server (NTRS)

    Ehsan, N.; Esper, J.; Piepmeier, J.; Racette, P.; Wu, D.

    2014-01-01

    Cloud ice properties and processes play fundamental roles in atmospheric radiation and precipitation. Limited knowledge and poor representation of clouds in global climate models have led to large uncertainties about cloud feedback processes under climate change. Ice clouds have been used as a tuning parameter in the models to force agreement with observations of the radiation budget at the top of the atmosphere, and precipitation at the bottom. The lack of ice cloud measurements has left the cloud processes at intermediate altitudes unconstrained. Millimeter (mm) and submillimeter (submm)-wave radiometry is widely recognized for its potential to fill the cloud measurement gap in the middle and upper troposphere. Analyses have shown that channels from 183900 GHz offer good sensitivity to ice cloud scattering and can provide ice water path (IWP) products to an accuracy of 25 by simultaneously retrieving ice particle size (Dme) and IWP. Therefore, it is highly desirable to develop a cost-effective, compact mm/submm-wave instrument for cloud observations that can be deployed on future small satellites.This paper presents a conceptual study for a mm/submm-wave instrument for multispectral measurements of ice clouds. It discusses previous work at these frequencies by NASA Goddard Space Flight Center (GSFC) and the current instrument study, as well as receiver architectures and their anticipated performance. And finally, it describes a microsatellite prototype intended for use with this mm/submm-wave instrument.

  6. A Millimeter-Wave Digital Link for Wireless MRI.

    PubMed

    Aggarwal, Kamal; Joshi, Kiran R; Rajavi, Yashar; Taghivand, Mazhareddin; Pauly, John M; Poon, Ada S Y; Scott, Greig

    2017-02-01

    A millimeter (mm) wave radio is presented in this work to support wireless MRI data transmission. High path loss and availability of wide bandwidth make mm-waves an ideal candidate for short range, high data rata communication required for wireless MRI. The proposed system uses a custom designed integrated chip (IC) mm-wave radio with 60 GHz as radio frequency carrier. In this work, we assess performance in a 1.5 T MRI field, with the addition of optical links between the console room and magnet. The system uses ON-OFF keying (OOK) modulation for data transmission and supports data rates from 200 Mb/s to 2.5 Gb/s for distances up-to 65 cm. The presence of highly directional, linearly polarized, on-chip dipole antennas on the mm-wave radio along with the time division multiplexing (TDM) circuitry allows multiple wireless links to be created simultaneously with minimal inter-channel interference. This leads to a highly scalable solution for wireless MRI.

  7. Millimeter-wave imaging of thermal and chemical signatures.

    SciTech Connect

    Gopalsami, N.

    1999-03-30

    Development of a passive millimeter-wave (mm-wave) system is described for remotely mapping thermal and chemical signatures of process effluents with application to arms control and nonproliferation. Because a large amount of heat is usually dissipated in the air or waterway as a by-product of most weapons of mass destruction facilities, remote thermal mapping may be used to detect concealed or open facilities of weapons of mass destruction. We have developed a focal-plane mm-wave imaging system to investigate the potential of thermal mapping. Results of mm-wave images obtained with a 160-GHz radiometer system are presented for different target scenes simulated in the laboratory. Chemical and nuclear facilities may be identified by remotely measuring molecular signatures of airborne molecules emitted from these facilities. We have developed a filterbank radiometer to investigate the potential of passive spectral measurements. Proof of principle is presented by measuring the HDO spectral line at 80.6 GHz with a 4-channel 77-83 GHz radiometer.

  8. Quantum Tunneling Sb-Heterostructures for Millimeter Wave Radiometry

    NASA Astrophysics Data System (ADS)

    Schulman, Joel N.

    2003-03-01

    Imaging in the millimeter wavelength range has been making rapid progress as high speed electronics increase in frequency. Applications include viewing through adverse visibility conditions (fog, smoke, dust, precipitation) and also the relative transparency of clothing (concealed-weapons-detection) and some building materials (through-the-wall-detection). Atmospheric radiometry (climate assessment and weather prediction) already depend heavily on this wavelength range. Astronomical applications include incorporation in instruments for cosmic microwave background detection. An important ingredient is a diode that "rectifies" in a special way. It must convert input power, i.e., voltage squared, into a DC voltage output -- a "square-law" detector. We have recently found that quantum tunneling through an InAs/AlSb/GaAlSb heterostructure system provides the ideal physical mechanism for this purpose.1,2 We will present our results to date, demonstrating how a close coupling of semiconductor quantum tunneling theory with electrical engineering know-how have brought an "exotic" quantum phenomon to practical and economic application. 1. "Sb-heterostructure interband backward diodes" J.N. Schulman and D.H. Chow. IEEE Electron Device Letters 21, 353-355 (2000). 2. "High-Performance Antimonide-Based Heterostructure Backward Diodes for Millimeter-wave Detection" P. Fay, J. N. Schulman, S. Thomas III, D. H. Chow, Y. K. Boegeman, and K. S. Holabird, IEEE Electron Device Letters 23, 585-587 (2002).

  9. Passive millimeter-wave imaging for concealed article detection

    NASA Astrophysics Data System (ADS)

    Lovberg, John A.; Galliano, Joseph A., Jr.; Clark, Stuart E.

    1997-02-01

    Passive-millimeter-wave imaging (PMI) provides a powerful sensing tool for law enforcement, allowing an unobtrusive means for detecting concealed weapons, explosives, or contraband on persons or in baggage. Natural thermal emissions at millimeter wavelengths from bodies, guns, explosives, and other articles pass easily through clothing or other concealment materials, where they can be detected and converted into conventional 2-dimensional images. A new implementation of PMI has demonstrated a large-area, near- real-time staring capability for personnel inspection at standoff ranges of greater than 10 meters. In this form, PMI does not require operator cuing based on subjective 'profiles' of suspicious appearance or behaviors, which may otherwise be construed as violations of civil rights. To the contrary, PMI detects and images heat generated by any object with no predisposition as to its nature or function (e.g. race or gender of humans). As a totally passive imaging tool, it generates no radio-frequency or other radiation which might raise public health concerns. Specifics of the new PMI architecture are presented along with a host of imaging data representing the current state- of-the-art.

  10. Millimeter-wave Absorption Studies of Molecules in Diffuse Clouds

    NASA Astrophysics Data System (ADS)

    Lucas, Robert; Liszt, Harvey S.

    1999-10-01

    With IRAM instruments in the last few years, we have been using compact extragalactic millimeter wave radio sources as background objects to study the absorption spectrum of diffuse interstellar gas at millimeter wavelengths. The molecular content of interstellar gas has turned out to be unexpectedly rich. Simple polyatomic molecules such as HCO+, C2H are quite ubiquitous near the Galactic plane (beta < 15o), and many species are detected in some directions (CO, HCO+, H2CO, HCN, HNC, CN, C2H, C3H2, H2S, CS, HCS+, SO, SiO). Remarkable proportionality relations are found between related species such as HCO+ and OH, or CN, HCN and HNC. The high abundance of some species is still a challenge for current models of diffuse cloud chemistry. A factor of 10 increase in the sensitivity will make such studies achievable in denser clouds, where the chemistry is still more active and where abundances are nowadays only available by emission measurements, and thus subject to uncertainties due to sometimes poorly understood line formation and excitation conditions.

  11. Measurements of millimeter wave radar transmission and backscatter during dusty infrared test 2, dirt 2

    NASA Astrophysics Data System (ADS)

    Petito, F. C.; Wentworth, E. W.

    1980-05-01

    Recently there has been much interest expressed to determine the ability of millimeter wave radar to perform target acquisition during degraded visibility conditions. In this regard, one of the primary issues of concern has been the potential of high-explosive artillery barrages to obscure the battlefield from millimeter wave radar systems. To address this issue 95 GHz millimeter wave radar measurements were conducted during the Dusty Infrared Test 2 (DIRT 2). This test was held at White Sands Missile Range, NM, 18-28 July 1979. Millimeter wave transmission and backscatter measurements were performed during singular live firings and static detonations of 155 mm and 105 mm high-explosive artillery rounds in addition to static detonations of C-4 explosives. A brief description of the millimeter wave portion of the test and instrumentation is given. The data along with some preliminary conclusions are presented.

  12. Dual mode millimeter wave/IR seeker for endoatmospheric interceptors

    NASA Astrophysics Data System (ADS)

    Mobley, Stacie; Moody, Henry L.; Graves, Craig M.; Elsherbiny, Moniem; Trolinger, James

    1992-02-01

    This paper describes a dual mode seeker that may be considered for an endoatmospheric interceptor. The seeker consists of a 35 GHz active, broadband-conformal antenna array and an optical window with an infrared Holographic Optical Element (HOE). The antenna consists of high Q, broadband, dual polarized antenna elements in a conformal array. The microwave beam is electronically steered over the desired field-of-view. The antenna elements are packaged in the wall of a high modulus honeycomb structure. The IR system entails a sapphire window with a HOE applied to its inside surface to focus incident target energy onto a detector array. The use of a HOE over conventional optics (consisting of lens-mirror systems) reduces weight and allows greater flexibility in internal packaging. The millimeter wave array and optical window(s) are actively cooled and packaged in a high strength-stiff metal structure to minimize the effects of high heating-high aeroloads on seeker performance.

  13. Passive millimeter-wave imaging for security and safety applications

    NASA Astrophysics Data System (ADS)

    Sato, Hiroyasu; Sawaya, Kunio; Mizuno, Koji; Uemura, Jun; Takeda, Masamune; Takahashi, Junichi; Yamada, Kota; Morichika, Keiichi; Hasegawa, Tsuyoshi; Hirai, Haruyuki; Niikura, Hirotaka; Matsuzaki, Tomohiko; Kato, Shigeto; Nakada, Jun

    2010-04-01

    77 GHz passive millimeter wave (PMMW) imaging camera for the purpose of security is developed. In order to detect concealed objects in clothes without hindrance to flow of people at airport security checks, video rate imaging is realized using one-dimensional imaging sensor array of 25 elements and a flapping reflector. As receiving antennas, novel antipodal Fermi antenna (APFA) having required characteristics for passive imaging such as broad bandwidth to obtain enough power, axially symmetric directivity with 10dB beam width of 35 degrees to obtain optimum coupling with dielectric lens, narrow width geometry for high spatial resolution of imaging is used. Real-time calibration (RTC) technique is introduced to eliminate the drift of receiving circuits. Interpolation technique to improve the quality of image and marking software for screening of suspicious objects are also developed. High spatial resolution of 20 mm is obtained by using developed imaging camera.

  14. Localized Heat Urticaria from 95-GHz Millimeter Waves.

    PubMed

    Gibbons, John A

    2017-06-01

    Local heat urticaria is a physical urticaria caused by the environmental stimulus of heat. Typically, the resultant lesion, a wheal, is pruritic (itches) and is sometimes accompanied by a burning sensation. It is a self-limited phenomenon that resolves after 1.5-2 h. The prevalence of local heat urticaria in the general population has been estimated as 1 in 200,000 persons. The subject, a 39-yr-old active duty man, participated in a test of a 95-GHz energy beam designed to heat the skin. He had delayed presentation of raised, erythematous, nonpruritic, nonpainful areas at five of the exposure sites where the skin temperature exceeded 54°C. All wheals resolved within 2 h of the exposures.Gibbons JA. Localized heat urticaria from 95-GHz millimeter waves. Aerosp Med Hum Perform. 2017; 88(6):586-588.

  15. Identification of passive millimeter-wave images using neural networks

    NASA Astrophysics Data System (ADS)

    Sundstrom, Bryce M.; Min, Kwang-Shik

    1993-09-01

    Recent developments in passive millimeter-wave imaging technology are remarkable. Images of objects obtained through clouds and fog are almost indistinguishable from similar scenes taken under clear conditions. Of particular interest is the ability to image metal targets beneath camouflage, tents, polymers, wooden shelters, and certain levels of ceramic materials. A brief description of this emerging technology will be followed by several convincing examples of images to support the claims made above. Once image formation is complete, the technique of identifying objects in the image using neural networks is similar to the schemes utilized in previous Wright Laboratory Armament directorate implementations of Automatic Target Identification work for electro-optical and infrared images.

  16. New law enforcement applications of millimeter-wave radar

    NASA Astrophysics Data System (ADS)

    Currie, Nicholas C.; Ferris, David D., Jr.; McMillan, Robert W.; Wicks, Michael C.

    1997-06-01

    Recent advances in millimeter-wave (MMW) radar technologies provide new applications for law enforcement use over-and- above the venerable speed timing radar. These applications include the potential to detect weapons under clothing and to conduct surveillance through walls. Concealed Weapon Detection and covert surveillance are of high interest to both the Department of Defense in support of Small Unit Operations and the Justice Department for civilian law enforcement applications. MMW sensors are under development which should provide the needed capabilities including radiometric sensors at 95 GHz, active 95 GHz real aperture radars, active focal plane array (FPA) radars, and holographic radars. Radiometric sensors include 2D FPA systems, 1D FPA, scanned systems, and single element scanned sensors. Active FPA radars include illuminated radiometric systems and coherent radar systems. Real aperture MMW radar systems include raster scanned and conical scanned sensors. Holographic systems ruse mechanical scanners to collect coherent data over a significant solid angular sector.

  17. Probe impedance measurements for millimeter-wave integrated horn antennas

    NASA Technical Reports Server (NTRS)

    Guo, Yong; Chiao, Jung-Chih; Potter, Kent A.; Rutledge, David B.

    1993-01-01

    In order to achieve an impedance-matched millimeter-wave integrated horn antenna mixer array, the characteristics of the antenna probes inside the horn must be known. This paper describes impedance measurements for various probes in low-frequency model horns of two different types: (1) a 3 x 3 array made of aluminum by electric discharge machining and (2) a half horn made of copper sheet placed on a big copper-clad circuit board that was used as an image plane. The results of measurements indicate that the presence of the horn increases the effective length of the probe element, in agreement with reports of Guo et al. (1991) and theoretical analysis of Eleftheriades et al. (1991). It was also found that the resonant frequencies can be controlled by changing the length of the probes or by loading the probes.

  18. An 8 GHz digital spectrometer for millimeter-wave astronomy

    NASA Astrophysics Data System (ADS)

    García, Roberto G.; Gentaz, Olivier; Baldino, Maryse; Torres, Marc

    2012-09-01

    We have designed and tested a digital spectrometer suitable for analyzing 8 GHz baseband signals. It is based on a 16- Gsps, 5-bit ADC from e2v and a Stratix-IV FPGA employed for later filtering and signal processing. Digitized data is received and synchronized via twenty high-speed 4-Gbps transceivers integrated in the FPGA. A 64-channel polyphase filter bank separates the input signal into 250-MHz sub-bands, allowing subsequent high-resolution analysis. To obtain continuous spectral information over the input bandwidth, we have implemented a 50% overlapping architecture solution. Subsequently these sub-bands are processed using Fast Fourier Transform modules. This system meets present-day demands on high-resolution wideband digital back-ends for millimeter-wave telescopes. This technology will be part of the next generation wideband correlator for the future upgrade of the IRAM Plateau de Bure interferometer (NOEMA project).

  19. The Millimeter Wave Observatory antenna now at INAOE-Mexico

    NASA Astrophysics Data System (ADS)

    Luna, A.

    2017-07-01

    The antenna of 5 meters in diameter of the legendary "Millimeter Wave Observatory" is now installed in the INAOE-Mexico. This historic antenna was reinstalled and was equipped with a control system and basic primary focus receivers that enabled it in teaching activities. We work on the characterization of its surface and on the development of receivers and spectrometers to allow it to do research Solar and astronomical masers. The historical contributions of this antenna to science and technology in radio astronomy, serve as the guiding force and the inspiration of the students and technicians of our postgrade in Astrophysics. It is enough to remember that it was with this antenna, that the first molecular outflow was discovered, several lines of molecular emission were discovered and it was the first antenna whose surface was characterized by holography; among many other technological and scientific contributions.

  20. Active millimeter-wave imaging using a raster scanner

    NASA Astrophysics Data System (ADS)

    Hülsmann, Axel; Liebelt, Andreas; Tessmann, Axel; Leuther, Arnulf; Schlechtweg, Michael; Ambacher, Oliver

    2009-05-01

    A millimeter-wave imaging system has been developed operating at a center frequency of 94 GHz. The system has a single stationary mounted transmit and receive lensed horn antenna and two moving mirrors in x and y. The beam is generated by a FMCW-radar module. The final beam aperture is an off-set parabolic mirror which focuses the beam to a small spot at 2 m distance. Key component of the FMCW radar module is a MMIC, which includes a VCO, a MPA/HPA, two Lange-couplers, an LNA , a Wilkenson splitter, and an I/Q-mixer. This MMIC is fabricated using IAF's 100 nm metamorphic HEMT process.

  1. T-SENSE a millimeter wave scanner for letters

    NASA Astrophysics Data System (ADS)

    Nüßler, Dirk; Heinen, Sven; Sprenger, Thorsten; Hübsch, Daniel; Würschmidt, Tobais

    2013-10-01

    Letter bombs are an increasing problem for public authorities, companies and public persons. Nowadays every big company uses in his headquarters inspection system to check the incoming correspondence. Generally x-ray systems are used to inspect complete baskets or bags of letters. This concept which works very fine in big company with a large postal center is not usable for small companies or private persons. For an office environment with a small number of letters x-ray systems are too expensive and oversized. X-ray systems visualize the wires and electric circuits inside the envelope. If a letter contains no metallic components but hazard materials or drugs, the dangerous content is invisible for the most low-cost x-ray systems. Millimeter wave imagining systems offer the potential to close this gap.

  2. Permittivity of water at millimeter wave-lengths

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1976-01-01

    Work performed on the permittivity of seawater and ice at 100 GHz was described. Measurements on water covered the temperature range from 0 to 50 C, while the measurements on ice were taken near - 10 C. In addition, a small number of measurements were made on the reflectivity of absorber materials used in a previous program on research in millimeter wave techniques. Normal incidence reflectivity was measured, and the result was used to obtain the index of refraction. For the case of normal incidence, reflectivity at a fixed temperature was reproducible to 1% for values near 40%. For reflectivity measurements on ice, the lack of attenuation leads to reflection from the back surface of the sample; this complication was circumvented by using a wedge shaped sample and freezing the water in a container lined with absorber material.

  3. The influence of polarization on millimeter wave propagation through rain

    NASA Technical Reports Server (NTRS)

    Bostian, C. W.; Stutzman, W. L.; Wiley, P. H.; Marshall, R. E.

    1974-01-01

    The influence of polarization on millimeter wave propagation through rain is investigated. The experimental equipment consisted of a 1.43 km line-of-sight path with 4-foot diameter dual-polarized parabolic reflector antennas at each end. Linearly polarized 17.65 GHz signals were transmitted with the electric field vectors at plus 45 degrees and minus 45 degrees from the vertical. These polarizations were initially chosen to maximize the measured depolarization at any given rainfall rate. Later it was discovered that the cross polarization levels measured with plus or minus 45 degree linearly polarized signals are theoretically the least sensitive to variations in drop canting angle and this choice of polarization reduces the scatter in the data.

  4. The response of giant phospholipid vesicles to millimeter waves radiation.

    PubMed

    Ramundo-Orlando, Alfonsina; Longo, Giovanni; Cappelli, Mauro; Girasole, Marco; Tarricone, Luciano; Beneduci, Amerigo; Massa, Rita

    2009-07-01

    Due to the increasing interest in millimeter waves (MMW) applications in medicine and telecommunications, the investigation of their potential biological effects is of utmost importance. Here we report results of the study of interaction between low-intensity radiation at 53.37 GHz and giant vesicles. Direct optical observations of vesicles subjected to irradiation enabled the monitoring in real time of the response of vesicles. Physical changes of vesicles, i.e. elongation, induced diffusion of fluorescent dye di-8-ANEPPS, and increased attractions between vesicles are demonstrated. These effects are reversible and occur only during irradiation with a "switch on" of the effect requiring a short time. Since the average temperature change was very small the effects could not be attributed to thermal mechanisms. We assume that the interaction of MMW with lipid membrane leads to changes at the membrane-water interface, where charged and dipolar residues are located.

  5. An artificial dielectric leaky-wave-antenna for millimeter range

    NASA Astrophysics Data System (ADS)

    Vishvakarma, B. R.; Sharma, R. P.

    A new, artificial dielectric leaky-wave antenna for the millimeter range is proposed and its radiation characteristics and scanning capability are examined. The antenna has beam scanning of 40 deg when the frequency is varied from 70 to 90 GHz. The scanning rate is higher in the lower frequency ranges, and the scanning angle increases with the thickness of the AD slab. The beam width does not vary much with frequency, indicating that there is no significant beam shape deterioration over a relatively large sweep angle and frequency range. The antenna gain increases linearly with increasing frequency. An AD antenna using a ferrite medium makes it possible to steer the beamwith frequency as well as biasing magnetic field, rendering the antenna suitable for very precise beam steering.

  6. Airborne Millimeter-Wave Radiometric Observations of Cirrus Clouds

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Racette, P.

    1997-01-01

    This paper reports the first radiometric measurements of cirrus clouds in the frequency range of 89-325 GHz from a high-altitude aircraft flight. The measurements are conducted with a Millimeter-wave Imaging Radiometer (MIR) on board the NASA ER-2 aircraft over a region in northern Oklahoma. Aboard the same aircraft are a cloud lidar system and a multichannel radiometer operating at the visible and infrared wavelengths. The instrument ensemble is well suited for identifying cirrus clouds. It is shown that the depressions in brightness temperatures associated with a few intense cirrus clouds occur at all frequency channels of the MIR. Estimates of total ice water path of the cirrus clouds are derived from comparisons of radiative transfer calculations and observed brightness depressions.

  7. Dielectrically embedded flat mesh lens for millimeter waves applications.

    PubMed

    Pisano, Giampaolo; Ng, Ming Wah; Ozturk, Fahri; Maffei, Bruno; Haynes, Vic

    2013-04-10

    A flat lens based on subwavelength periodic metal meshes has been developed using photolithographic techniques. These mesh grids are stacked at specific distances and embedded in polypropylene. A code was developed to optimize more than 1000 transmission line circuits required to vary the device phase shift across the lens flat surface, mimicking the behavior of a classical lens. A W-band mesh-lens prototype was successfully manufactured and its RF performance characterized using a vector network analyzer coupled to corrugated horn antennas. Co-polarization far-field beam patterns were measured and compared with finite-element method models. The excellent agreement between data and simulations validated our designing tools and manufacturing procedures. This mesh lens is a low-loss, robust, light, and compact device that has many potential applications including millimeter wave quasi-optical systems for future cosmic microwave background polarization instruments.

  8. Propulsion of small launch vehicles using high power millimeter waves

    SciTech Connect

    Benford, J.; Myrabo, L.

    1994-12-31

    The use of microwave and millimeter wave beamed energy for propulsion of vehicles in the atmosphere and in space has been under study for at least 35 years. The need for improved propulsion technology is clear: chemical rockets orbit only a few percent of the liftoff mass at a cost of over $3,000/lb. The key advantage of the beamed power approach is to place the heavy and expensive components on the ground or in space, not in the vehicle. This paper, following upon the high power laser propulsion programs, uses a multi-cycle propulsion engine in which the first phase of ascent is based on the air breathing ramjet principle, a repetitive Pulsed Detonation Engine (PDE) which uses a microwave-supported detonation to heat the air working fluid, i.e., propellant. The second phase is a pure beam-heated rocket. The key factor is that high peak power is essential to this pulsed engine. This paper explores this propulsion concept using millimeter waves, the most advantageous part of the spectrum. The authors find that efficient system concepts can be developed for the beam powered launch system and that, while the capital cost may be as high as the earlier orbital transfer concepts, the operating cost is much lower. The vehicle can have payload-to-mass ratios on the order of one and cost (per pound to orbit) two orders of magnitudes less than for chemical rockets. This allows the weight of microwave powered vehicles to be very small, as low as {approximately}100 kg for test devices.

  9. Boring and Sealing Rock with Directed Energy Millimeter-Waves

    NASA Astrophysics Data System (ADS)

    Woskov, P.; Einstein, H. H.; Oglesby, K.

    2015-12-01

    Millimeter-wave directed energy is being investigated to penetrate into deep crystalline basement rock formations to lower well costs and to melt rocks, metals, and other additives to seal wells for applications that include nuclear waste storage and geothermal energy. Laboratory tests have established that intense millimeter-wave (MMW) beams > 1 kW/cm2 can melt and/ or vaporize hard crystalline rocks. In principle this will make it possible to create open boreholes and a method to seal them with a glass/ceramic liner and plug formed from the original rock or with other materials. A 10 kW, 28 GHz commercial (CPI) gyrotron system with a launched beam diameter of about 32 mm was used to heat basalt, granite, limestone, and sandstone specimens to temperatures over 2500 °C to create melts and holes. A calibrated 137 GHz radiometer view, collinear with the heating beam, monitored real time peak rock temperature. A water load surrounding the rock test specimen primarily monitored unabsorbed power at 28 GHz. Power balance analysis of the laboratory observations shows that the temperature rise is limited by radiative heat loss, which would be expected to be trapped in a borehole. The analysis also indicates that the emissivity (absorption efficiency) in the radiated infrared range is lower than the emissivity at 28 GHz, giving the MMW frequency range an important advantage for rock melting. Strength tests on one granite type indicated that heating the rock initially weakens it, but with exposure to higher temperatures the resolidified black glassy product regains strength. Basalt was the easiest to melt and penetrate, if a melt leak path was provided, because of its low viscosity. Full beam holes up to about 50 mm diameter (diffraction increased beam size) were achieved through 30 mm thick basalt and granite specimens. Laboratory experiments to form a seal in an existing hole have also been carried out by melting rock and a simulated steel casing.

  10. Visualization of Shock Wave Driven by Millimeter Wave Plasma in a Parabolic Thruster

    SciTech Connect

    Yamaguchi, Toshikazu; Shimada, Yutaka; Shiraishi, Yuya; Shibata, Teppei; Komurasaki, Kimiya; Oda, Yasuhisa; Kajiwara, Ken; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi; Arakawa, Yoshihiro

    2010-05-06

    By focusing a high-power millimeter wave beam generated by a 170 GHz gyrotron, a breakdown occurred and a shock wave was driven by plasma heated by following microwave energy. The shock wave and the plasma around a focal point of a parabolic thruster were visualized by a shadowgraph method, and a transition of structures between the shock wave and the plasma was observed. There was a threshold local power density to make the transition, and the propagation velocity at the transition was around 800 m/s.

  11. W-band real-time passive millimeter-wave imager for helicopter collision avoidance

    NASA Astrophysics Data System (ADS)

    Salmon, Neil A.

    1999-07-01

    A w-band passive millimeter imager is proposed for use on a helicopter platform. The atmospheric transmission through fog and rain is much higher in the millimeter wave band than it is in the visible or infrared regions of the spectrum. This property enables passive millimeter wave imaging systems to offer recognizable imagery in adverse weather conditions. Furthermore, as the technique is based on incoherent imaging, it can be used in environments where it may be difficult for radar to process data into recognizable imagery. The 30 cm diameter real-time passive millimeter wave imager described here will have a radiometric sensitivity of around 1 degree(s)C and a radiation bandwidth of 80 GHz to 105 GHz. The system is based on the DERA mechanical scanning passive millimeter wave imager architecture.

  12. Interferometric millimeter wave and THz wave doppler radar

    DOEpatents

    Liao, Shaolin; Gopalsami, Nachappa; Bakhtiari, Sasan; Raptis, Apostolos C.; Elmer, Thomas

    2015-08-11

    A mixerless high frequency interferometric Doppler radar system and methods has been invented, numerically validated and experimentally tested. A continuous wave source, phase modulator (e.g., a continuously oscillating reference mirror) and intensity detector are utilized. The intensity detector measures the intensity of the combined reflected Doppler signal and the modulated reference beam. Rigorous mathematics formulas have been developed to extract bot amplitude and phase from the measured intensity signal. Software in Matlab has been developed and used to extract such amplitude and phase information from the experimental data. Both amplitude and phase are calculated and the Doppler frequency signature of the object is determined.

  13. Method and apparatus for millimeter-wave detection of thermal waves for materials evaluation

    DOEpatents

    Gopalsami, Nachappa; Raptis, Apostolos C.

    1991-01-01

    A method and apparatus for generating thermal waves in a sample and for measuring thermal inhomogeneities at subsurface levels using millimeter-wave radiometry. An intensity modulated heating source is oriented toward a narrow spot on the surface of a material sample and thermal radiation in a narrow volume of material around the spot is monitored using a millimeter-wave radiometer; the radiometer scans the sample point-by-point and a computer stores and displays in-phase and quadrature phase components of thermal radiations for each point on the scan. Alternatively, an intensity modulated heating source is oriented toward a relatively large surface area in a material sample and variations in thermal radiation within the full field of an antenna array are obtained using an aperture synthesis radiometer technique.

  14. Image fusion based on millimeter-wave for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Zhu, Weiwen; Zhao, Yuejin; Deng, Chao; Zhang, Cunlin; Zhang, Yalin; Zhang, Jingshui

    2010-11-01

    This paper describes a novel multi sensors image fusion technology which is presented for concealed weapon detection (CWD). It is known to all, because of the good transparency of the clothes at millimeter wave band, a millimeter wave radiometer can be used to image and distinguish concealed contraband beneath clothes, for example guns, knives, detonator and so on. As a result, we adopt the passive millimeter wave (PMMW) imaging technology for airport security. However, in consideration of the wavelength of millimeter wave and the single channel mechanical scanning, the millimeter wave image has law optical resolution, which can't meet the need of practical application. Therefore, visible image (VI), which has higher resolution, is proposed for the image fusion with the millimeter wave image to enhance the readability. Before the image fusion, a novel image pre-processing which specifics to the fusion of millimeter wave imaging and visible image is adopted. And in the process of image fusion, multi resolution analysis (MRA) based on Wavelet Transform (WT) is adopted. In this way, the experiment result shows that this method has advantages in concealed weapon detection and has practical significance.

  15. Millimeter Wave and Terahertz Spectra of C-13 Methanol

    NASA Astrophysics Data System (ADS)

    Xu, Li-Hong; Lees, Ronald M.; Müller, Holger S. P.; Endres, Christian P.; Lewen, Frank; Schlemmer, Stephan; Menten, Karl M.

    2009-06-01

    Methanol is a very ubiquitous molecule in space. A previous combined analysis of microwave and millimeter wave spectra of C-13 methanol together with Fourier transform far-infrared spectra was limited to the first two torsional states (i.e. v_t = 0 and 1 for J values up to 20). We have recently carried out new millimeter and terahertz measurements for ^{13}CH_3OH on several different spectrometers in the Cologne laboratory to overcome the limits in frequency and quantum number coverage. The new measurements have been carried out in the frequency windows 34-70 GHz, 75-120 GHz, 240-340 GHz, 370-500 GHz and 1.12-1.35 THz. With the new data, we are extending our previous global treatment to include the first three torsional states (i.e. v_t = 0, 1 and 2 for J values up to 30). We hope to provide the radio astronomical community with a C-13 methanol database that will have been improved substantially compared to the existing one. The new database will be available in the Cologne Database for Molecular Spectroscopy, CDMS, in support of present and future astronomical studies associated with the launch of HIFI (Heterodyne Instrument for the Far-Infrared) on board the Herschel Space Observatory, the flying of SOFIA (Stratospheric Observatory For Infrared Astronomy) and the commissioning of ALMA (Atacama Large Millimeter/Submillimeter Array). Li-Hong Xu, M. S. Walsh, R. M. Lees, 1996, J. Mol. Spectrosc. 179, 269-281. Li-Hong Xu, F. J. Lovas, 1997, J. Phys. Chem. Ref. Data, 26, 17-156; also available in the CDMS, see ^c. H. S. P. Müller, S. Thorwirth, D. A. Roth, G. Winnewisser, 2001, Astron. Astrophys. 370, L49-L52 H. S. P. Müller, F. Schlöder, J. Stutzki, G. Winnewisser, 2005 J. Mol. Struct. 742, 215-227; web-page: http://www.astro.uni-koeln.de/cdms/.

  16. Millimeter and submillimeter wave spectra of 13C methylamine

    NASA Astrophysics Data System (ADS)

    Motiyenko, R. A.; Margulès, L.; Ilyushin, V. V.; Smirnov, I. A.; Alekseev, E. A.; Halfen, D. T.; Ziurys, L. M.

    2016-03-01

    Context. Methylamine (CH3NH2) is a light molecule of astrophysical interest, which has an intensive rotational spectrum that extends in the submillimeter wave range and far beyond, even at temperatures characteristic for the interstellar medium. It is likely for 13C isotopologue of methylamine to be identified in astronomical surveys, but there is no information available for the 13CH3NH2 millimeter and submillimeter wave spectra. Aims: In this context, to provide reliable predictions of 13CH3NH2 spectrum in millimeter and submillimeter wave ranges, we have studied rotational spectra of the 13C methylamine isotopologue in the frequency range from 48 to 945 GHz. Methods: The spectrum of 13C methylamine was recorded using conventional absorption spectrometers. The analysis of the rotational spectrum of 13C methylamine in the ground vibrational state was performed on the basis of the group-theoretical high-barrier tunneling Hamiltonian that was developed for methylamine. The available multiple observations of the parent methylamine species toward Sgr B2(N) at 1, 2, and 3 mm using the Submillimeter Telescope and the 12 m antenna of the Arizona Radio Observatory were used to make a search for interstellar 13CH3NH2. Results: In the recorded spectra, we have assigned 2721 rotational transitions that belong to the ground vibrational state of the 13CH3NH2. These measurements were fitted to the Hamiltonian model that uses 75 parameters to achieve an overall weighted rms deviation of 0.73. On the basis of these spectroscopic results, predictions of transition frequencies in the frequency range up to 950 GHz with J ≤ 50 and Ka ≤ 20 are presented. The search for interstellar 13C methylamine in available observational data was not successful and therefore only an upper limit of 6.5 × 1014 cm-2 can be derived for the column density of 13CH3NH2 toward Sgr B2(N), assuming the same source size, temperature, linewidth, and systemic velocity as for parent methylamine isotopic

  17. Beamforming Based Full-Duplex for Millimeter-Wave Communication

    PubMed Central

    Liu, Xiao; Xiao, Zhenyu; Bai, Lin; Choi, Jinho; Xia, Pengfei; Xia, Xiang-Gen

    2016-01-01

    In this paper, we study beamforming based full-duplex (FD) systems in millimeter-wave (mmWave) communications. A joint transmission and reception (Tx/Rx) beamforming problem is formulated to maximize the achievable rate by mitigating self-interference (SI). Since the optimal solution is difficult to find due to the non-convexity of the objective function, suboptimal schemes are proposed in this paper. A low-complexity algorithm, which iteratively maximizes signal power while suppressing SI, is proposed and its convergence is proven. Moreover, two closed-form solutions, which do not require iterations, are also derived under minimum-mean-square-error (MMSE), zero-forcing (ZF), and maximum-ratio transmission (MRT) criteria. Performance evaluations show that the proposed iterative scheme converges fast (within only two iterations on average) and approaches an upper-bound performance, while the two closed-form solutions also achieve appealing performances, although there are noticeable differences from the upper bound depending on channel conditions. Interestingly, these three schemes show different robustness against the geometry of Tx/Rx antenna arrays and channel estimation errors. PMID:27455256

  18. Millimeter-wave monolithic diode-grid frequency multiplier

    NASA Technical Reports Server (NTRS)

    Maserjian, Joseph (Inventor)

    1990-01-01

    A semiconductor diode structure useful for harmonic generation of millimeter or submillimeter wave radiation from a fundamental input wave is fabricated on a GaAs substrate. A heavily doped layer of n(sup ++) GaAs is produced on the substrate and then a layer of intrinsic GaAs on said heavily doped layer on top of which a sheet of heavy doping (++) is produced. A thin layer of intrinsic GaAs grown over the sheet is capped with two metal contacts separated by a gap to produce two diodes connected back to back through the n(sup ++) layer for multiplication of frequency by an odd multiple. If only one metal contact caps the thin layer of intrinsic GaAs, the second diode contact is produced to connect to the n(sup ++) layer for multiplication of frequency by an even number. The odd or even frequency multiple is selected by a filter. A phased array of diodes in a grid will increase the power of the higher frequency generated.

  19. Beamforming Based Full-Duplex for Millimeter-Wave Communication.

    PubMed

    Liu, Xiao; Xiao, Zhenyu; Bai, Lin; Choi, Jinho; Xia, Pengfei; Xia, Xiang-Gen

    2016-07-21

    In this paper, we study beamforming based full-duplex (FD) systems in millimeter-wave (mmWave) communications. A joint transmission and reception (Tx/Rx) beamforming problem is formulated to maximize the achievable rate by mitigating self-interference (SI). Since the optimal solution is difficult to find due to the non-convexity of the objective function, suboptimal schemes are proposed in this paper. A low-complexity algorithm, which iteratively maximizes signal power while suppressing SI, is proposed and its convergence is proven. Moreover, two closed-form solutions, which do not require iterations, are also derived under minimum-mean-square-error (MMSE), zero-forcing (ZF), and maximum-ratio transmission (MRT) criteria. Performance evaluations show that the proposed iterative scheme converges fast (within only two iterations on average) and approaches an upper-bound performance, while the two closed-form solutions also achieve appealing performances, although there are noticeable differences from the upper bound depending on channel conditions. Interestingly, these three schemes show different robustness against the geometry of Tx/Rx antenna arrays and channel estimation errors.

  20. Thermal and Behavioral Effects of Exposure to 30 kW, 95-GHz Millimeter Wave Energy

    DTIC Science & Technology

    2017-05-04

    AFRL-RH-FS-TR-2017-0016 Thermal and Behavioral Effects of Exposure to 30-kW, 95-GHz Millimeter Wave Energy James E. Parker Eric...30-kW, 95-GHz Millimeter Wave Energy " LELAND JOHNSON, DR-III, DAF Contract Monitor Radio Frequency Bioeffects Branch STEPHANIE A. MILLER, DRIV, DAF...CONTRACT NUMBER FA8650-13-D-6368-0007 Thermal and Behavioral Effects of Exposure to 30-kW, 95-GHz Millimeter Wave Energy 5b. GRANT NUMBER N/A

  1. Multispectral illumination and image processing techniques for active millimeter-wave concealed object detection.

    PubMed

    Zhang, Lixiao; Stiens, Johan; Elhawil, Amna; Vounckx, Roger

    2008-12-01

    Active millimeter-wave imaging systems for concealed object detection offer the possibility of much higher image contrast than passive systems, especially in indoor applications. By studying active millimeter-wave images of different test objects derived in the W band, we show that multispectral illumination is critical to the detectability of targets. We also propose to use image change detection techniques, including image differencing, normalized difference vegetation index, and principle component analysis to process the multispectral millimeter-wave images. The results demonstrate that multispectral illumination can significantly reveal the object features hidden by image artifacts and improve the appearance of the objects.

  2. Millimeter-Wave Dielectric Properties of Single Crystal Ferroelectric and Dielectric Materials

    SciTech Connect

    McCloy, John S.; Korolev, Konstantin A.; Li, Zijing; Afsar, Mohammed N.; Sundaram, S. K.

    2011-01-03

    Transmittance measurements on various single crystal ferroelectric materials over a broad millimeter-wave frequency range have been performed. Frequency dependence of the complex dielectric permittivity has been determined in the millimeter wave region for the first time. The measurements have been employed using a free-space quasi-optical millimeter-wave spectrometer equipped with a set of high power backward wave oscillators (BWOs) as sources of coherent radiation, tunable in the range from 30 - 120 GHz. The uncertainties and possible sources of instrumentation and measurement errors related to the free-space millimeter-wave technique are discussed. This work has demonstrated that precise MMW permittivities can be obtained even on small thin crystals using the BWO quasi-optical approach.

  3. Millimeter and submillimeter wave spectra of 13C-glycolaldehydes

    NASA Astrophysics Data System (ADS)

    Haykal, I.; Motiyenko, R. A.; Margulès, L.; Huet, T. R.

    2013-01-01

    Context. Glycolaldehyde (CH2OHCHO) is the simplest sugar and an important intermediate in the path toward forming more complex biologically relevant molecules. Astronomical surveys of interstellar molecules, such as those available with the very sensitive ALMA telescope, require preliminary laboratory investigations of the microwave and submillimeter-wave spectra of molecular species including new isotopologs - to identify these in the interstellar media. Aims: To achieve the detection of the 13C isotopologs of glycolaldehyde in the interstellar medium, their rotational spectra in the millimeter and submillimeter-wave regions were studied. Methods: The spectra of 13CH2OHCHO and CH2OH13CHO were recorded in the 150-945 GHz spectral range in the laboratory using a solid-state submillimeter-wave spectrometer in Lille. The observed line frequencies were measured with an accuracy of 30 kHz up to 700 GHz and of 50 kHz above 700 GHz. We analyzed the spectra with a standard Watson Hamiltonian. Results: About 10 000 new lines were identified for each isotopolog. The spectroscopic parameters were determined for the ground- and the three lowest vibrational states up to 945 and 630 GHz. Previous microwave assignments of 13CH2OHCHO were not confirmed. Conclusions: The provided line-lists and sets of molecular parameters meet the needs for a first astrophysical search of 13C-glycolaldehydes. Full Tables 3 and 4 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/549/A96

  4. Observation and modeling of atmospheric oxygen millimeter-wave transmittance

    NASA Astrophysics Data System (ADS)

    Schwartz, Michael Jonathan

    1998-12-01

    The Microwave Temperature Sounder (MTS) was used on multiple ascents and descents of NASA ER-2 aircraft to measure downwelling thermal atmospheric emission viewed from 0-20-km altitudes in millimeter-wave bands dominated by molecular oxygen, and to infer atmospheric opacity in these bands. The MTS includes two super-heterodyne receivers: one with eight IF channels covering 350-2000 MHz from the 118.75-GHz oxygen line and the other with a 30-200-MHz IF and a tunable LO stepped through eight frequencies from 52.7-55.6 GHz. Simulations of MTS zenith-view antenna temperatures based upon local radiosondes and the MPM92 absorption model of Liebe, et al. (50) were consistent with observations in the 52.5- 55.8 GHz band. Adjustment of the temperature dependence exponent of the 118.75-GHz linewidth from the MPM92 value of 0.8 to 0.97 ± 0.03 was found to produce significantly better agreement in observations with MTS channels centered on this line. This increase in low- temperature linewidth changes total atmospheric opacity in these channels by less than 2.5 percent. Other investigators have noted systematic discrepancies as large as several Kelvin between measured and simulated upwelling brightness temperatures, both in satellite observations of the earth in the 50-60 GHz band and in nadirial-viewed MTS observations from 20-km altitude in the band 116.7-120.8 GHz. Resolution of these biases through adjustment of the oxygen absorption model requires increases in the MPM92 expression of up to 20 percent. The utility of current and proposed satellite- based millimeter-wave temperature sounders for the monitoring of global climate, the initialization of numerical weather models, and the remote monitoring of severe weather systems is compromised by this model uncertainty. The zenith-viewing configuration through ascents and descents of the current MTS measurements are several times more sensitive to perturbation of atmospheric opacity than are space-based observations. The

  5. Effect of millimeter waves on natural killer cell activation.

    PubMed

    Makar, V R; Logani, M K; Bhanushali, A; Kataoka, M; Ziskin, M C

    2005-01-01

    Millimeter wave therapy (MMWT) is being widely used for the treatment of many diseases in Russia and other East European countries. MMWT has been reported to reduce the toxic effects of chemotherapy on the immune system. The present study was undertaken to investigate whether millimeter waves (MMWs) can modulate the effect of cyclophosphamide (CPA), an anticancer drug, on natural killer (NK) cell activity. NK cells play an important role in the antitumor response. MMWs were produced with a Russian-made YAV-1 generator. The device produced modulated 42.2 +/- 0.2 GHz radiation through a 10 x 20 mm rectangular output horn. Mice, restrained in plastic tubes, were irradiated on the nasal area. Peak SAR at the skin surface and peak incident power density were measured as 622 +/- 100 W/kg and 31 +/- 5 mW/cm2, respectively. The maximum temperature elevation, measured at the end of 30 min, was 1 degrees C. The animals, restrained in plastic tubes, were irradiated on the nasal area. CPA injection (100 mg/kg) was given intraperitoneally on the second day of 3-days exposure to MMWs. All the irradiation procedures were performed in a blinded manner. NK cell activation and cytotoxicity were measured after 2, 5, and 7 days following CPA injection. Flow cytometry of NK cells showed that CPA treatment caused a marked enhancement in NK cell activation. The level of CD69 expression, which represents a functional triggering molecule on activated NK cells, was increased in the CPA group at all the time points tested as compared to untreated mice. However, the most enhancement in CD69 expression was observed on day 7. A significant increase in TNF-alpha level was also observed on day 7 following CPA administration. On the other hand, CPA caused a suppression of the cytolytic activity of NK cells. MMW irradiation of the CPA treated groups resulted in further enhancement of CD69 expression on NK cells, as well as in production of TNF-alpha. Furthermore, MMW irradiation restored CPA

  6. Microwave and millimeter-wave resonant tunneling diodes

    NASA Technical Reports Server (NTRS)

    Sollner, T. C. L. Gerhard; Brown, Elliott R.; Goodhue, W. D.

    1987-01-01

    Several demonstrated resonant tunneling devices including oscillators, mixers, multiplexers, and a variable negative resistance are discussed. Techniques of the millimeter/submillimeter regime are also discussed.

  7. Compact Packaging of Photonic Millimeter-Wave Receiver

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung; Pouch, John; Miranda, Felix; Levi, Anthony F.

    2007-01-01

    A carrier structure made from a single silicon substrate is the basis of a compact, lightweight, relatively inexpensive package that holds the main optical/electronic coupling components of a photonic millimeter-wave receiver based on a lithium niobate resonator disk. The design of the package is simple and provides for precise relative placement of optical components, eliminating the need for complex, bulky positioning mechanisms like those commonly used to align optical components to optimize focus and coupling. Although a prototype of the package was fabricated as a discrete unit, the design is amenable to integration of the package into a larger photonic and/or electronic receiver system. The components (see figure) include a lithium niobate optical resonator disk of 5-mm diameter and .200- m thickness, positioned adjacent to a millimeter- wave resonator electrode. Other components include input and output coupling prisms and input and output optical fibers tipped with ball lenses for focusing and collimation, respectively. Laser light is introduced via the input optical fiber and focused into the input coupling prism. The input coupling prism is positioned near (but not in contact with) the resonator disk so that by means of evanescent-wave coupling, the input laser light in the prism gives rise to laser light propagating circumferentially in guided modes in the resonator disk. Similarly, a portion of the circumferentially propagating optical power is extracted from the disk by evanescent-wave coupling from the disk to the output coupling prism, from whence the light passes through the collimating ball lens into the output optical fiber. The lens-tipped optical fibers must be positioned at a specified focal distance from the prisms. The optical fibers and the prisms must be correctly positioned relative to the resonator disk and must be oriented to obtain the angle of incidence (55 in the prototype) required for evanescent-wave coupling of light into and out

  8. Millimeter wave sensor requirements for maritime small craft identification

    NASA Astrophysics Data System (ADS)

    Krapels, Keith; Driggers, Ronald G.; Garcia, Jose; Boettcher, Evelyn; Prather, Dennis; Schuetz, Chrisopher; Samluk, Jesse; Stein, Lee; Kiser, William; Visnansky, Andrew; Grata, Jeremy; Wikner, David; Harris, Russ

    2009-09-01

    Passive millimeter wave (mmW) imagers have improved in terms of resolution sensitivity and frame rate. Currently, the Office of Naval Research (ONR), along with the US Army Research, Development and Engineering Command, Communications Electronics Research Development and Engineering Center (RDECOM CERDEC) Night Vision and Electronic Sensor Directorate (NVESD), are investigating the current state-of-the-art of mmW imaging systems. The focus of this study was the performance of mmW imaging systems for the task of small watercraft / boat identification field performance. First mmW signatures were collected. This consisted of a set of eight small watercrafts; at 5 different aspects, during the daylight hours over a 48 hour period in the spring of 2008. Target characteristics were measured and characteristic dimension, signatures, and Root Sum Squared of Target's Temperature (RRSΔT) tabulated. Then an eight-alternative, forced choice (8AFC) human perception experiment was developed and conducted at NVESD. The ability of observers to discriminate between small watercraft was quantified. Next, the task difficulty criterion, V50, was quantified by applying this data to NVESD's target acquisition models using the Targeting Task Performance (TTP) metric. These parameters can be used to evaluate sensor field performance for Anti-Terrorism / Force Protection (AT/FP) and navigation tasks for the U.S. Navy, as well as for design and evaluation of imaging passive mmW sensors for both the U.S. Navy and U.S. Coast Guard.

  9. Near-field millimeter-wave imaging for weapons detection

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Collins, H. D.; Hall, Thomas E.

    1993-04-01

    Various millimeter-wave imaging systems capable of imaging through clothing for the detection of contraband metal, plastic, or ceramic weapons, have been developed at PNL. Two dimensional scanned holographic systems, developed at 35, 90, and 350 GHz, are used to obtain high resolution images of metal and plastic targets concealed by clothing. Coherent single-frequency amplitude and phase data, which is gathered over a two-dimensional scanned aperture, is reconstructed to the target plane using a holographic wavefront reconstruction technique. Practical weapon detection systems require high-speed scanning. To achieve this goal, a 35 GHz linear sequentially switched array has been built and integrated into a high speed linear scanner. This system poses special challenges on calibration/signal processing of the holographic system. Further, significant improvements in speed are required to achieve real time operation. Toward this goal, a wideband scanned system which allows for a two- dimensional image formation from a one-dimensional scanned (or array) system has been developed. Signal/image processing techniques developed and implemented for this technique are a variation on conventional synthetic aperture radar (SAR) techniques which eliminate far- field and narrow-bandwidth requirements. Performance of this technique is demonstrated with imaging results obtained from a Ka-band system.

  10. Near-field millimeter-wave imaging for weapon detection

    SciTech Connect

    Sheen, D.M.; McMakin, D.L.; Collins, H.D.; Hall, T.E.

    1992-11-01

    Various millimeter-wave imaging systems capable of imaging through clothing for the detection of contraband metal, plastic, or ceramic weapons, have been developed at PNL. Two dimensional scanned holographic systems, developed at 35, 90, and 350 GHz, are used to obtain high resolution images of metal and plastic targets concealed by clothing. Coherent single-frequency amplitude and phase data, which is gathered over a two-dimensional scanned aperture, is reconstructed to the target plane using a holographic wavefront reconstruction technique. Practical weapon detection systems require high-speed scanning. To achieve this goal, a 35 GHz linear sequentially switched array has been built and integrated into a high speed linear scanner. This system poses special challenges on calibration / signal processing of the holographic system. Further, significant improvements in speed are required to achieve real time operation. Toward this goal, a wideband scanned system which allows for a two-dimensional image formation from a one-dimensional scanned (or array) system has been developed . Signal / image processing techniques developed and implemented for this technique are a variation on conventional synthetic aperture radar (SAR) techniques which eliminate far-field and narrow bandwidth requirements. Performance of this technique is demonstrated with imaging results obtained from a K[sub a]-band system.

  11. Near-field millimeter-wave imaging for weapon detection

    SciTech Connect

    Sheen, D.M.; McMakin, D.L.; Collins, H.D.; Hall, T.E.

    1992-11-01

    Various millimeter-wave imaging systems capable of imaging through clothing for the detection of contraband metal, plastic, or ceramic weapons, have been developed at PNL. Two dimensional scanned holographic systems, developed at 35, 90, and 350 GHz, are used to obtain high resolution images of metal and plastic targets concealed by clothing. Coherent single-frequency amplitude and phase data, which is gathered over a two-dimensional scanned aperture, is reconstructed to the target plane using a holographic wavefront reconstruction technique. Practical weapon detection systems require high-speed scanning. To achieve this goal, a 35 GHz linear sequentially switched array has been built and integrated into a high speed linear scanner. This system poses special challenges on calibration / signal processing of the holographic system. Further, significant improvements in speed are required to achieve real time operation. Toward this goal, a wideband scanned system which allows for a two-dimensional image formation from a one-dimensional scanned (or array) system has been developed . Signal / image processing techniques developed and implemented for this technique are a variation on conventional synthetic aperture radar (SAR) techniques which eliminate far-field and narrow bandwidth requirements. Performance of this technique is demonstrated with imaging results obtained from a K{sub a}-band system.

  12. Microwave and millimeter-wave systems for wall penetration

    NASA Astrophysics Data System (ADS)

    Ferris, David D., Jr.; Currie, Nicholas C.

    1998-07-01

    The need for through-the-wall surveillance sensors has existed for many years. Recent advances in microwave and millimeter-wave (MMW) technologies provide new applications for law enforcement use. These applications include the potential to conduct surveillance through walls and the ability to detect the presence of living persons behind doors or other barriers. Covert surveillance and personnel detection are of high interest to both the Department of Defense in support of Small Unit Operations and the Justice Department for civilian law enforcement applications. Microwave sensors are under development that can detect the presence of persons (and even weapons) behind walls and track moving persons behind walls. MMW sensors are under development which can provide pseudo-images of persons behind the walls including radiometric sensors at 95 GHz, active 95 GHz real aperture radars, and heartbeat detection radars. Radiometric sensors include 2D FPA systems, 1D FPA, scanned systems, and single element scanned sensors. Active FPA radars include illuminated radiometric systems and coherent radar systems. Real aperture MMW radar systems include raster scanned and non-scanned (hand-held) sensors.

  13. Passive millimeter-wave camera with interferometric processing

    NASA Astrophysics Data System (ADS)

    Nohmi, Hitoshi; Ohnishi, Seiki; Kujubu, Osamu

    2007-04-01

    A proto-type passive millimeter-wave (MMW) camera with interferometric processing has been developed and evaluated to confirm the feasibility of the interferometric MMW camera and to study the characteristics of MMW images. This proto-type camera is comprised of the minimum configuration as an interferometric imager which consists of two sets of a W-band receiver with a horn antenna, and a digital processing unit. The position of these two antennas with W-band front-end moves on the precision linear slider in horizontal and vertical axis. The coherently amplified two channel signals are digitized and processed in the hardware processor. The process is comprised of correlation of all combination of each axis data, and integration to improve the signal to noise ratio. The integrated data is processed to make an image by matched filter processing. The integration time is from 1mS to 10S depending on required integration gain. The maximum synthesized antenna aperture size is 1m for horizontal axis and 50cm for vertical axis. In this paper, the evaluation of the proto-type P-MMW camera is descried. After the evaluation, some improvement was scheduled and conducted. Also, future plan for a real-time camera using this technique is presented .

  14. Millimeter-wave spotlight imager using dynamic holographic metasurface antennas.

    PubMed

    Yurduseven, Okan; Marks, Daniel L; Fromenteze, Thomas; Gollub, Jonah N; Smith, David R

    2017-07-24

    Computational imaging systems leverage generalized measurements to produce high-fidelity images, enabling novel and often lower cost hardware platforms at the expense of increased processing. However, obtaining full resolution images across a large field-of-view (FOV) can lead to slow reconstruction times, limiting system performance where faster frame rates are desired. In many imaging scenarios, the highest resolution is needed only in smaller subdomains of interest within a scene, suggesting an aperture supporting multiple modalities of image capture with different resolutions can provide a path to system optimization. We explore this concept in the context of millimeter-wave imaging, presenting the design and simulation of a single frequency (75 GHz), multistatic, holographic spotlight aperture integrated into a K-band (17.5-26.5 GHz), frequency-diverse imager. The spotlight aperture - synthesized using an array of dynamically tuned, holographic, metasurface antennas - illuminates a constrained region-of-interest (ROI) identified from a low-resolution image, extracting a high-fidelity image of the constrained-ROI with a minimum number of measurement modes. The designs of both the static, frequency-diverse sub-aperture and the integrated dynamic spotlight aperture are evaluated using simulation techniques developed for large-scale synthetic apertures.

  15. 3D volumetric radar using 94-GHz millimeter waves

    NASA Astrophysics Data System (ADS)

    Takács, Barnabás

    2006-05-01

    This article describes a novel approach to the real-time visualization of 3D imagery obtained from a 3D millimeter wave scanning radar. The MMW radar system employs a spinning antenna to generate a fan-shaped scanning pattern of the entire scene. The beams formed this way provide all weather 3D distance measurements (range/azimuth display) of objects as they appear on the ground. The beam width of the antenna and its side lobes are optimized to produce the best possible resolution even at distances of up to 15 Kms. To create a full 3D data set the fan-pattern is tilted up and down with the help of a controlled stepper motor. For our experiments we collected data at 0.1 degrees increments while using both bi-static as well as a mono-static antennas in our arrangement. The data collected formed a stack of range-azimuth images in the shape of a cone. This information is displayed using our high-end 3D visualization engine capable of displaying high-resolution volumetric models with 30 frames per second. The resulting 3D scenes can then be viewed from any angle and subsequently processed to integrate, fuse or match them against real-life sensor imagery or 3D model data stored in a synthetic database.

  16. Compressive sampling in passive millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Gopalsami, N.; Elmer, T. W.; Liao, S.; Ahern, R.; Heifetz, A.; Raptis, A. C.; Luessi, M.; Babacan, D.; Katsaggelos, A. K.

    2011-05-01

    We present a Hadamard transform based imaging technique and have implemented it on a single-pixel passive millimeter-wave imager in the 146-154 GHz range. The imaging arrangement uses a set of Hadamard transform masks of size p x q at the image plane of a lens and the transformed image signals are focused and collected by a horn antenna of the imager. The cyclic nature of Hadamard matrix allows the use of a single extended 2-D Hadamard mask of size (2p-1) x (2q-1) to expose a p x q submask for each acquisition by raster scanning the large mask one pixel at a time. A total of N = pq acquisitions can be made with a complete scan. The original p x q image may be reconstructed by a simple matrix operation. Instead of full N acquisitions, we can use a subset of the masks for compressive sensing. In this regard, we have developed a relaxation technique that recovers the full Hadamard measurement space from sub-sampled Hadamard acquisitions. We have reconstructed high fidelity images with 1/9 of the full Hadamard acquisitions, thus reducing the image acquisition time by a factor of 9.

  17. Millimeter Wave Active Sensing Technology For Self-Contained Munitions

    NASA Astrophysics Data System (ADS)

    Hunton, Andrew J.

    1983-10-01

    Active millimeter wave (MMW) sensing technology is playing an increasing role throughout the DoD research and development community in the area of Self Contained Munitions (SCM's), autonomous missiles and armament primarily intended for air and surface launched standoff antiarmor weapon systems. Each type of SCM, which requires fire-and-forget search, detection, discrimination and warhead aiming sensing functions, places varied operational, packaging and performance specifications on its MMW sensor subsystem. This paper attempts to portray the rationale for implementation of active MMW sensing devices into SCM's, along with a description of the spectrum of SCM sensor operational parameters. A treatise of active MMW sensor technologies required for ultimate successful weaponization will include discussions in the areas of signal processing and MMW RF hardware. Ultimately, as active MMW technology matures, the critical trade between complexity, cost and effectiveness must be analyzed for each SCM type. A qualitative discussion in this area will be covered as well, yielding insight into future MMW development areas which require increased heavy emphasis in order to meet the stringent requirements on SCM active MMW sensing subsystems.

  18. Investigation of gigawatt millimeter wave source applications. Final technical report

    SciTech Connect

    Bruder, J.A.; Belcher, M.L.

    1991-09-01

    The Georgia Tech Research Institute (GTRI) investigated potential applications of millimeter wave (MMW) sources with peak powers on the order of a gigawatt. This power level is representative of MMW devices such as the free electron laser (FEL) and the cyclotron auto-resonance maser (CARM) that are under development at the Lawrence Livermore National Laboratory (LLNL). In addition to determining the technical requirements for these applications, the investigation considered potential users and how a high power MMW system would expand their current capabilities. Two of the more promising applications were examined in detail to include trade-off evaluations system parameters. The trade-off evaluations included overall system configuration, frequency and coherence, component availability, and performance estimates. Brainstorming sessions were held to try and uncover additional applications for a gigawatt MMW source. In setting up guidelines for the session, the need to attempt to predict applications for the years 2000 to 2030 was stressed. Also, possible non-DoD applications needed to be considered. While some of these applications could not in themselves justify the costs involved in the development of the radar system, they could be considered potential secondary applications of the system. As a result of the sessions, a number of interesting potential applications evolved including: space object identification; low angle tracking; illuminator for space-based radar; radio astronomy; space vehicle navigation; space debris location; atmospheric research; wind shear detection; electronic countermeasures; low observable detection; and long range detection via ducting.

  19. Urban area navigation using active millimeter-wave radar

    NASA Astrophysics Data System (ADS)

    Corken, Richard A.; Evans, Michael A.

    2002-08-01

    An active MilliMeter Wave (MMW) system exploiting forward squinting Synthetic Aperture Radar (SAR) techniques can provide high resolution imagery. Such a radar offers a compact, all weather, day/night solution to the problem of accurate airborne navigation. Interpreting radar imagery of very cluttered urban areas is challenging, thus complicating autonomous navigation within such areas. For example, imagery is subject to effects such as layover distortions due to the height of buildings and also considerable radar shadowing. In this paper we examine the use of synthetic imagery to capture the key elements of the radar imagery. The MMW imagery can then be related to the physical models from which the synthetic imagery is generated leading to improved scene understanding. This paper describes the modeling process adopted and compares real imagery from a 35GHz forward squinting SAR radar with the synthetically generated imagery. The modeling process includes provision for terrain undulation, man-made and natural clutter regions and the ability to generate a sequence of imagery from a specified flight path. Examples presented include a representative urban area containing a variety of building structures. An important part of this research is the required fidelity of the synthetic scene model and therefore investigations into the level of detail required are also presented. Further work aims to exploit the synthetic imagery for navigational purposes through registration with the actual radar image thereby automatically locating key building structures with the imagery.

  20. Compressive sensing for direct millimeter-wave holographic imaging.

    PubMed

    Qiao, Lingbo; Wang, Yingxin; Shen, Zongjun; Zhao, Ziran; Chen, Zhiqiang

    2015-04-10

    Direct millimeter-wave (MMW) holographic imaging, which provides both the amplitude and phase information by using the heterodyne mixing technique, is considered a powerful tool for personnel security surveillance. However, MWW imaging systems usually suffer from the problem of high cost or relatively long data acquisition periods for array or single-pixel systems. In this paper, compressive sensing (CS), which aims at sparse sampling, is extended to direct MMW holographic imaging for reducing the number of antenna units or the data acquisition time. First, following the scalar diffraction theory, an exact derivation of the direct MMW holographic reconstruction is presented. Then, CS reconstruction strategies for complex-valued MMW images are introduced based on the derived reconstruction formula. To pursue the applicability for near-field MMW imaging and more complicated imaging targets, three sparsity bases, including total variance, wavelet, and curvelet, are evaluated for the CS reconstruction of MMW images. We also discuss different sampling patterns for single-pixel, linear array and two-dimensional array MMW imaging systems. Both simulations and experiments demonstrate the feasibility of recovering MMW images from measurements at 1/2 or even 1/4 of the Nyquist rate.

  1. Aqueous blackbody calibration source for millimeter-wave/terahertz metrology

    SciTech Connect

    Dietlein, Charles; Popovic, Zoya; Grossman, Erich N

    2008-10-20

    This paper describes a calibrated broadband emitter for the millimeter-wave through terahertz frequency regime, called the aqueous blackbody calibration source. Due to its extremely high absorption, liquid water is chosen as the emitter on the basis of reciprocity. The water is constrained to a specific shape (an optical trap geometry) in an expanded polystyrene (EPS) container and maintained at a selected, uniform temperature. Uncertainty in the selected radiometric temperature due to the undesirable reflectance present at a water interface is minimized by the trap geometry, ensuring that radiation incident on the entrance aperture encounters a pair of s and a pair of p reflections at 45 deg. . For water reflectance Rw of 40% at 45 deg. in W-band, this implies a theoretical effective aperture emissivity of (1-R{sup 2}wsR{sup 2}wp)>98.8%. From W-band to 450 GHz, the maximum radiometric temperature uncertainty is {+-}0.40 K, independent of water temperature. Uncertainty from 450 GHz to 1 THz is increased due to EPS scattering and absorption, resulting in a maximum uncertainty of -3 K at 1 THz.

  2. Microwave and millimeter-wave Doppler radar heart sensing

    NASA Astrophysics Data System (ADS)

    Boric-Lubecke, Olga; Lin, Jenshan; Lubecke, Victor M.; Host-Madsen, Anders; Sizer, Tod

    2007-04-01

    Technology that can be used to unobtrusively detect and monitor the presence of human subjects from a distance and through barriers can be a powerful tool for meeting new security challenges, including asymmetric battlefield threats abroad and defense infrastructure needs back home. Our team is developing mobile remote sensing technology for battle-space awareness and warfighter protection, based on microwave and millimeter-wave Doppler radar motion sensing devices that detect human presence. This technology will help overcome a shortfall of current see-through-thewall (STTW) systems, which is, the poor detection of stationary personnel. By detecting the minute Doppler shifts induced by a subject's cardiopulmonary related chest motion, the technology will allow users to detect personnel that are completely stationary more effectively. This personnel detection technique can also have an extremely low probability of intercept since the signals used can be those from everyday communications. The software and hardware developments and challenges for personnel detection and count at a distance will be discussed, including a 2.4 GHz quadrature radar single-chip silicon CMOS implementation, a low-power double side-band Ka-band transmission radar, and phase demodulation and heart rate extraction algorithms. In addition, the application of MIMO techniques for determining the number of subjects will be discussed.

  3. Millimeter-wave Molecular Line Observations of the Tornado Nebula

    NASA Astrophysics Data System (ADS)

    Sakai, D.; Oka, T.; Tanaka, K.; Matsumura, S.; Miura, K.; Takekawa, S.

    2014-08-01

    We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15' × 15' area was mapped in the J = 1-0 lines of CO, 13CO, and HCO+ with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V LSR = -14 km s-1 and +5 km s-1. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado "head" in the -14 km s-1 cloud, also suggesting the interaction. Virial analysis shows that the +5 km s-1 cloud is more tightly bound by self-gravity than the -14 km s-1 cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s-1 cloud collided into the -14 km s-1 cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

  4. Millimeter-Wave Spectroscopy of Hydrazoic Acid (HN3)

    NASA Astrophysics Data System (ADS)

    Amberger, Brent K.; Esselman, Brian J.; Woods, R. Claude; McMahon, Robert J.

    2014-06-01

    The rotational spectra for hydrazoic acid (HN3), its isotopologues, and its vibrational satellites have been reexamined using millimeter-wave rotational spectroscopy in the range of 240-360 GHz. Treating sodium azide (NaN3) or the commercially available singly 15N-labeled NaN3 with phosphoric acid or deuterated phosphoric acid yielded 6 different isotopologues. From these samples, we were also able to observe all of the isotopologues containing one additional 15N at natural abundance. In total, we assigned rotational transitions to 14 different species; only H15N3 and D15N3 were not accessible. With the large number of rotational constants determined for these isotopologues, an excellent equilibrium structure determination was performed with CFOUR's xrefit routine. This structure shows a bent azide sub-unit, and is in excellent agreement with the geometry optimization performed at the CCSD(T)/ANO2 level of theory. The Coriolis perturbation of the ground and first two vibrationally excited states of HN3 will also be discussed.

  5. Future applications of millimeter waves for space communications

    NASA Astrophysics Data System (ADS)

    Rusch, Roger J.

    1996-12-01

    The past 30 years have witnessed the introduction and phenomenal improvement of digital communications services. Several characteristics emerge when looking at the trends. First, capacity and capability of communications networks are growing rapidly. Next, local and personal access to digital services is expanding. Finally, ordinary 4 kHz analog voice lines are now providing 28.8 kbps digital services in the home. Only 15 years ago, this data rate was 300 bps, a growth factor of 96 in 15 years or 36 percent per year. In addition, clever data compression techniques have reduced the data rates required for speech and video, and we now have the ability to provide video conferencing on computers using existing terrestrial networks. As the world makes greater use of wireless communications, hundreds of satellites are orbiting in space to provide fixed and mobile services. Because of the large number of satellites, the geostationary orbit is heavily used. More sophisticated satellites could be designed, but a simpler solution is to move to higher frequencies offered by millimeter wave bands. Dozens of US companies are currently developing systems that will provide high data services to the world.

  6. Passive millimeter-wave cross polarization imaging and phenomenology

    NASA Astrophysics Data System (ADS)

    Stein, E. Lee, Jr.; Schuetz, Christopher A.; Martin, Richard D.; Samluk, Jesse P.; Wilson, John P.; Mackrides, Daniel G.; Murakowski, Janusz A.; Murakowski, Maciej; Prather, Dennis W.

    2009-05-01

    Passive millimeter-wave (mmW) imaging has many specific defense, security and safety applications, due to the fact that all terrestrial bodies above absolute zero are emissive, and these wavelengths are not scattered by normal obscurants such as haze, fog, smoke, dust, sandstorms, clouds, or fabrics. We have previously demonstrated results from the construction of a 94 GHz passive mmW far-field imaging system utilizing optical upconversion, which imaged in only horizontal polarization. The effective radiometric temperature of an object is a combination of the object's surface and scattered radiometric temperatures. The surface radiometric temperature is a function of the object's emissivity, which is polarization dependent. Imaging with radiometric temperature data from both polarizations will allow a greater identification of the scene being imaged, and allow the recognition of subtle features which were not previously observable. This additional functionality is accomplished through the installation of added equipment and programming on our system, thus allowing the simultaneous data collection of imagery in both polarizations. Herein, we present our experimental procedures, results and passive mmW images obtained by using our far-field imaging system, a brief discussion of the phenomenology observed through the application of these techniques, as well as the preliminary details regarding our work on a 3-D passive mmW simulator capable of true physical polarization dependent effective emissivity and reflectivity rendering, based on the open-source Blender engine.

  7. Cylindrical millimeter-wave imaging technique and applications

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2006-05-01

    The wideband microwave or millimeter-wave cylindrical imaging technique has been developed at Pacific Northwest National Laboratory (PNNL) for several applications including concealed weapon detection and automated body measurement for apparel fitting. This technique forms a fully-focused, diffraction-limited, three-dimensional image of the person or imaging target by scanning an inward-directed vertical array around the person or imaging target. The array is switched electronically to sequence across the array at high-speed, so that a full 360 degree mechanical scan over the cylindrical aperture can occur in 2-10 seconds. Wideband, coherent reflection data from each antenna position are recorded in a computer and subsequently reconstructed using an FFT-based image reconstruction algorithm developed at PNNL. The cylindrical scanning configuration is designed to optimize the illumination of the target and minimize non-returns due to specular reflection of the illumination away from the array. In this paper, simulated modeling data are used to explore imaging issues that affect the cylindrical imaging technique. Physical optics scattering simulations are used to model realistic returns from curved surfaces to determine the extent to which specular reflection affects the signal return and subsequent image reconstruction from these surfaces. This is a particularly important issue for the body measurement application. Also, an artifact in the imaging technique, referred to as "circular convolution aliasing" is discussed including methods to reduce or eliminate it. Numerous simulated and laboratory measured imaging results are presented.

  8. A millimeter-wave radiometer for detecting microbursts

    NASA Technical Reports Server (NTRS)

    Mcmillan, Robert

    1992-01-01

    This paper describes a millimeter-wave radiometer for the detection of wind shear from airborne platforms or at airport terminals. This proposed instrument will operate near the group of atmospheric oxygen absorptions centered near 60 GHz, which it will use to sense temperature from a distance. The instrument will use two channels to provide two different temperature measurements, providing the basis for solution of two equations in two unknowns, which are range to the wind shear plume and its temperature. A third channel will measure ambient atmospheric temperature. Depending on the temperature difference between the wind-shear plume and ambient, the standard deviation of range measurement accuracy is expected to be about 1 km at 5 km range, while the temperature measurement standard deviation will be about one-fourth the temperature difference between plume and ambient at this range. The instrument is expected to perform usefully at ranges up to 10 km, giving adequate warning of the presence of wind shear even for high performance jet aircraft. Other atmospheric hazards which might be detected by this radiometer include aircraft wakes and vortices, clear-air turbulence, and wind rotors, although the latter two phenomena would be detected by an airborne version of the instrument. A separate radiometer channel will be provided in the proposed instrument to detect aircraft wakes and vortices based on perturbation of the spectrum of microscopic atmospheric temperature fluctuations caused by the passage of large aircraft.

  9. Thermal Mechanisms of Millimeter Wave Stimulation of Excitable Cells

    PubMed Central

    Shapiro, Mikhail G.; Priest, Michael F.; Siegel, Peter H.; Bezanilla, Francisco

    2013-01-01

    Interactions between millimeter waves (MMWs) and biological systems have received increasing attention due to the growing use of MMW radiation in technologies ranging from experimental medical devices to telecommunications and airport security. Studies have shown that MMW exposure alters cellular function, especially in neurons and muscles. However, the biophysical mechanisms underlying such effects are still poorly understood. Due to the high aqueous absorbance of MMW, thermal mechanisms are likely. However, nonthermal mechanisms based on resonance effects have also been postulated. We studied MMW stimulation in a simplified preparation comprising Xenopus laevis oocytes expressing proteins that underlie membrane excitability. Using electrophysiological recordings simultaneously with 60 GHz stimulation, we observed changes in the kinetics and activity levels of voltage-gated potassium and sodium channels and a sodium-potassium pump that are consistent with a thermal mechanism. Furthermore, we showed that MMW stimulation significantly increased the action potential firing rate in oocytes coexpressing voltage-gated sodium and potassium channels, as predicted by thermal terms in the Hodgkin-Huxley model of neurons. Our results suggest that MMW stimulation produces significant thermally mediated effects on excitable cells via basic thermodynamic mechanisms that must be taken into account in the study and use of MMW radiation in biological systems. PMID:23790370

  10. Performance modeling of a passive interferometric millimeter-wave sensor

    NASA Astrophysics Data System (ADS)

    Jacobs, Eddie L.; Furxhi, Orges

    2009-05-01

    This paper describes the modeling of human task performance using a passive interferometric millimeter wave (MMW) imaging sensor. The model is based on a previous model developed for concealed weapon identification using an active terahertz imager. Both models leverage the task performance modeling approach developed by the US Army Night Vision and Electronic Sensors Directorate. Key developments for this model include modeling of the effects of an interferometric antenna array, including sparse arrays, and a novel optical upconversion and processing stage being developed by the University of Delaware. Sparse interferometric arrays do not fully sample the spatial frequency extent of the image and as a result, can have degraded spatial frequency response over a fully populated array. The spatial frequency response of the sparse array can have a dramatic effect on image quality. Image quality is empirically related to task performance through the use of perception experiments. Possible applications of this model include system trade studies, concealed weapon identification, and navigation in fog and brown out conditions.

  11. Topics in the optimization of millimeter-wave mixers

    NASA Technical Reports Server (NTRS)

    Siegel, P. H.; Kerr, A. R.; Hwang, W.

    1984-01-01

    A user oriented computer program for the analysis of single-ended Schottky diode mixers is described. The program is used to compute the performance of a 140 to 220 GHz mixer and excellent agreement with measurements at 150 and 180 GHz is obtained. A sensitivity analysis indicates the importance of various diode and mount characteristics on the mixer performance. A computer program for the analysis of varactor diode multipliers is described. The diode operates in either the reverse biased varactor mode or with substantial forward current flow where the conversion mechanism is predominantly resistive. A description and analysis of a new H-plane rectangular waveguide transformer is reported. The transformer is made quickly and easily in split-block waveguide using a standard slitting saw. It is particularly suited for use in the millimeter-wave band, replacing conventional electroformed stepped transformers. A theoretical analysis of the transformer is given and good agreement is obtained with measurements made at X-band.

  12. Propulsion of small launch vehicles using high power millimeter waves

    SciTech Connect

    Benford, J.; Myrabo, L.

    1994-12-31

    High power microwaves have been proposed for propulsion of vehicles and projectiles in the atmosphere and in space. The requirements in terms of high power microwave technology have not been examined in any detail. The need for improved propulsion technology is clear: chemical rockets orbit only a few percent of the liftoff mass at a cost of about 3,000$/lb. The key advantage of any beamed power approach is in placing the heavy and expensive components on the ground or in space. The authors propose a system with uses a two-stage propulsion method in which the first phase of ascent is based on the ramjet principle, a repetitive Pulsed Detonation Engine which uses a microwave-supported detonation to heat the air fuel. The second phase is a pure rocket. This paper explores this propulsion concept using millimeter waves, the most advantageous part of the spectrum. They find that efficient system concepts can be developed: the vehicle can have payload-to-mass ratios on the order of one and cost per pound to orbit one or two orders of magnitude less that chemical rockets.

  13. A 190GHz active millimeter-wave imager

    NASA Astrophysics Data System (ADS)

    Brothers, Michael L.; Timms, Greg P.; Bunton, John D.; Archer, John W.; Tello, Juan Y.; Rosolen, Grahame C.; Li, Yue; Hellicar, Andrew D.

    2007-04-01

    The design and testing of a 190 GHz imaging system is presented. The system features two beam-scanning antennas; the first transmits a horizontal fan beam and the second receives a vertical fan beam. By correlating the signals from the antennas, an estimate of the millimeter-wave reflectivity at the intersection of the fan beams is obtained. Each fan beam is scanned by rotating a small subreflector within the antenna; this simple rotation motion allows rapid scanning. The system is portable, currently approximately 0.6m × 0.6m × 2m high; the key size constraint is imposed by the 450 mm aperture length of the antennas. The imager has an angular resolution of 0.25° and a field of view of 14°×14°, resulting in a raw image of approximately 50 × 50 pixels. The raw image is processed using super-resolution techniques. Images will be presented which show the capability of the system to image metallic and ceramic objects beneath clothing. These images were obtained by illuminating the scene with signals from a frequency-doubled Gunn oscillator. While this paper focuses on active imaging, the system can also operate in passive mode with reduced sensitivity.

  14. Active millimeter wave detection of concealed layers of dielectric material

    NASA Astrophysics Data System (ADS)

    Bowring, N. J.; Baker, J. G.; Rezgui, N. D.; Southgate, M.; Alder, J. F.

    2007-04-01

    Extensive work has been published on millimetre wave active and passive detection and imaging of metallic objects concealed under clothing. We propose and demonstrate a technique for revealing the depth as well as the outline of partially transparent objects, which is especially suited to imaging layer materials such as explosives and drugs. The technique uses a focussed and scanned FMCW source, swept through many GHz to reveal this structure. The principle involved is that a parallel sided dielectric slab produces reflections at both its upper and lower surfaces, acting as a Fabry-Perot interferometer. This produces a pattern of alternating reflected peaks and troughs in frequency space. Fourier or Burg transforming this pattern into z-space generates a peak at the thickness of the irradiated sample. It could be argued that though such a technique may work for single uniform slabs of dielectric material, it will give results of little or no significance when the sample both scatters the incident radiation and gives erratic reflectivities due to its non-uniform thickness and permittivity . We show results for a variety of materials such as explosive simulants, powder and drugs, both alone and concealed under clothing or in a rucksack, which display strongly directional reflectivities at millimeter wavelengths, and whose location is well displayed by a varying thickness parameter as the millimetre beam is scanned across the target. With this system we find that samples can easily be detected at standoff distances of at least 4.6m.

  15. Studies of millimeter-wave phenomenology for helicopter brownout mitigation

    NASA Astrophysics Data System (ADS)

    Schuetz, Christopher A.; Stein, E. Lee, Jr.; Samluk, Jesse; Mackrides, Daniel; Wilson, John P.; Martin, Richard D.; Dillon, Thomas E.; Prather, Dennis W.

    2009-09-01

    The unique ability of the millimeter-wave portion of the spectrum to penetrate typical visual obscurants has resulted in a wide range of possible applications for imagers in this spectrum. Of particular interest to the military community are imagers that can operate effectively in Degraded Visual Environments (DVE's) experienced by helicopter pilots when landing in dry, dusty environments, otherwise known as "brownout." One of the first steps to developing operational requirements for imagers in this spectrum is to develop a quantitative understanding of the phenomenology that governs imaging in these environments. While preliminary studies have been done in this area, quantitative, calibrated measurements of typical targets and degradation of target contrasts due to brownout conditions are not available. To this end, we will present results from calibrated, empirical measurements of typical targets of interest to helicopter pilots made in a representative desert environment. In addition, real-time measurements of target contrast reduction due to brownout conditions generated by helicopter downwash will be shown. These data were acquired using a W-band, dual-polarization radiometric scanner using optical-upconversion detectors.

  16. Millimeter Wave Tunneling-Rotational Spectrum of Phenol

    NASA Astrophysics Data System (ADS)

    Kolesnikova, L.; Daly, A. M.; Alonso, J. L.; Tercero, B.; Cernicharo, J.

    2013-06-01

    The millimeter wave spectra of phenol in the vibrational ground state and the first excited states of the bending and torsion vibrational modes have been studied in the frequency regions of 140 - 170 GHz and 280 - 360 GHz. The internal rotation of the hydroxyl group is responsible for the observed tunneling splitting into two substates (v_{t}, v_{b})^{+} and (v_{t}, v_{b})^{-} and more than 3500 distinct tunneling-rotational ^{b}R- and ^{b}Q-type transitions between them were measured and analyzed. Furthermore, accidental near degeneracies of the (+) and (-) energy levels were observed in case of the ground state and the v_{b} = 1 excited state and the analysis using a two-state effective Hamiltonian including tunneling-rotational Coriolis terms was performed. The spectroscopic constants for the first excited states of the bending and the torsion vibrational modes have been determined for the first time. The analysis of the microwave data provided very precise values of the spectroscopic constants necessary for the astrophysical search of phenol. We report a tentative detection for this molecule in the IRAM 30m line survey of Orion KL.

  17. The millimeter wave tunneling-rotational spectrum of phenol

    NASA Astrophysics Data System (ADS)

    Kolesniková, L.; Daly, A. M.; Alonso, J. L.; Tercero, B.; Cernicharo, J.

    2013-07-01

    The millimeter wave spectra of phenol in the vibrational ground state and the first excited states of the bending and torsion vibrational modes have been studied in the frequency regions of 140-170 GHz and 280-360 GHz. The internal rotation of the hydroxyl group is responsible for the observed tunneling splitting into two substates (vt, vb)+ and (vt, vb)- and more than 3500 distinct tunneling-rotational bR- and bQ-type transitions between them were measured and analyzed. Furthermore, accidental near degeneracies of the (±) and (-) energy levels were observed in case of the ground state and the vb = 1 excited state and the analysis using a two-state effective Hamiltonian including tunneling-rotational Coriolis-like terms was performed. The analysis of the microwave data provided very precise values of the spectroscopic constants necessary for the astrophysical search of phenol. We report a tentative detection for this molecule in the IRAM 30m line survey of Orion KL.

  18. Adaptive reconstruction of millimeter-wave radiometric images.

    PubMed

    Sarkis, Michel

    2012-09-01

    We present a robust method to reconstruct a millimeter-wave image from a passive sensor. The method operates directly on the raw samples from the radiometer. It allocates for each pixel to be estimated a patch in the space formed by all the raw samples of the image. It then estimates the noise in the patch by measuring some distances that reflect how far the samples are from forming a piecewise smooth surface. It then allocates a weight for each sample that defines its contribution in the pixel reconstruction. This is done via a smoothing Kernel that enforces the distances to have a piecewise smooth variation inside the patch. Results on real datasets show that our scheme leads to more contrast and less noise and the shape of an object is better preserved in a constructed image compared to state-of-the-art schemes. The proposed scheme produces better results even with low integration times, i.e., 10% of the total integration time used in our experiments.

  19. Millimeter waves as a source of selective heating of skin.

    PubMed

    Zhadobov, Maxim; Alekseev, Stanislav I; Le Dréan, Yves; Sauleau, Ronan; Fesenko, Evgeny E

    2015-09-01

    This study demonstrates that 20-100 GHz range can be used for spatially-accurate focusing of heating inside the skin achieved by varying frequency and exposure beam size, as well as by enforcing air convection. The latter is also used to reduce overheating of skin surface. Heating at different skin depths depending on these parameters is investigated in detail using the hybrid bio-heat equation. In particular, it is shown that decreasing frequency and/or increasing exposure beam size at forced airflow result in elevation of heating of deeper layers of tissue and decrease of skin surface temperature. Changes of water content within 15%, which exceed those due to aging and presence of tumors, only slightly affect heating. Exposure intensity necessary to reach a target temperature significantly increases in different areas of body with elevated blood flow. Dependence on exposure intensity and hyperthermia treatment duration is also investigated and discussed. Results of this study suggest that the lower part of the millimeter-wave range is an attractive alternative for non-invasive thermal treatment of skin cancer with a high spatial resolution.

  20. Future trends in millimeter-wave receiver design

    NASA Astrophysics Data System (ADS)

    Cardiasmenos, A. G.

    1981-06-01

    The development of short wave receivers with low noise and narrow bandwidths in the millimeter range and directions being followed for mass production for military use are presented. It is noted that surface-oriented GaAs diodes with less than .018 pFd capacitance and series resistance of 3-4 ohms are now available for receiver subassemblies. Schottky diodes are suitable for 20-300 GHz, with optimization so far centering around 94 GHz, and fabrication by thermocompression allows mass production, eliminates whisker induced mechanical failure, and permits high reliability piece-to-piece. Continuing antenna design is noted, as are 15 transmission line media currently known, with fused silica offering the most substantial production history. Broader bandwidths and low cost approaches based on microstrip lines are argued with tradeoffs between noise, cost, and performance. FET IF amplifiers are projected to become practical in the 40-140 GHz region and production parameters for MIC circuits, local oscillator source inclusion, MIC modules, and monolithic GaAs mixer circuits are discussed for electronic warfare, radar warning, and communications applications.

  1. Research on metal-plated cellulose nitrate flakes and their infrared / millimeter wave characteristics

    NASA Astrophysics Data System (ADS)

    Ye, Shu-qin; Zhu, Chen-guang; Wang, Li-hong; Ou'yang, De-hua; Pan, Gong-pei

    2016-10-01

    Copper-plated and silver-plated cellulose nitrate flakes, which were prepared by using chemical plating technology, were used to jam infrared detector and millimeter-wave radar. It was tested for the conductivity and infrared jamming performance of plating and also the RCS (Radar Cross Section) performance of millimeter-wave radar. Test results showed that the prepared metal-plated cellulose nitrate flakes have obvious conductivity, and infrared total radiation energy of silver plating and copper plating had approximately increased 32% and 21% respectively. Through determination, the millimeter-wave reflecting property and RCS of silver-plated cellulose nitrate flakes were higher than that of copper-plated cellulose nitrate flakes. Therefore, silver-plated cellulose nitrate flakes can be used as an effective infrared / millimeter wave composite jamming material.

  2. Comments on ferrite phase shifter configurations for the millimeter wave region

    NASA Astrophysics Data System (ADS)

    Reuss, M. L., Jr.

    1982-09-01

    In the microwave region of the electromagnetic spectrum, electronically controllable ferrite phase shifters have demonstrated their value as components and as control elements for switches and attenuators. As the need for control components operating in the lower millimeter wave region increases, it is a reasonable approach to scale successful microwave ferrite configurations into the lower millimeter wave region (30 GHz to 140 GHz). However, many problems are encountered when attempting to scale efficient microwave ferrite configurations, particularly latching ferrite configurations, into the millimeter wave region. It is the objective of this report to review several ferrite configurations with the intent that consideration of these configurations may stimulate development of practical millimeter wave configurations. Ferrite phase shifter configurations that will be the subject of comment include the toroidal (dual slab), dual mode, Bush-Reggia-Spencer, and single slab configurations. Comments are also presented on a circulator used as a phase shifter.

  3. W-Band Technology and Techniques for Analog Millimeter-Wave Photonics

    DTIC Science & Technology

    2015-08-19

    available technology and standard techniques for millimeter-wave photonics at frequencies up to 110 GHz. Measured data for commercial electro-optic...Measured data for commercial electro- optic phase modulators, electro-optic intensity modulators, p-i-n photodiodes and waveguide photodetectors...millimeter-wave application is associated with wireless links [5-7], radio astronomy [8], or military systems, the main components that determine the

  4. Advanced MMIC Receiver for 94-GHz Band Passive Millimeter-Wave Imager

    NASA Astrophysics Data System (ADS)

    Sato, Masaru; Hirose, Tatsuya; Mizuno, Koji

    In this paper, we present the development of an advanced MMIC receiver for a 94-GHz band passive millimeter-wave (PMMW) imager. Our configuration is based on a Dicke receiver in order to reduce fluctuations in the detected voltage. By introducing an electronic switch in the MMIC, we achieved a high resolution millimeter-wave image in a shorter image collection time compared to that with a conventional mechanical chopper. We also developed an imaging array using MMIC receivers.

  5. The millimeter wave spectrum and discharge chemistry of HC5N

    NASA Astrophysics Data System (ADS)

    Winnewisser, G.; Winnewisser, M.; Christiansen, J. J.

    1982-05-01

    The laboratory millimeter wave spectrum of HC5N has been measured up to 210 GHz, yielding refined ground state parameters [B0 = 1331.332714(47) MHz, D0 = 30.1017(58) Hz] and highly precise frequency predictions throughout the millimeter wave region. The discharge of any combination of hydrocarbons and a source of nitrogen such as HCN will generate HC3N and HC5N in observable quantities. Some of these reactions will probably be of astrophysical significance.

  6. EEG changes as heat stress reactions in rats irradiated by high intensity 35 GHz millimeter waves.

    PubMed

    Xie, Taorong; Pei, Jian; Cui, Yibin; Zhang, Jie; Qi, Hongxing; Chen, Shude; Qiao, Dengjiang

    2011-06-01

    As the application of millimeter waves for civilian and military use increases, the possibility of overexposure to millimeter waves will also increase. This paper attempts to evaluate stress reactions evoked by 35 GHz millimeter waves. The stress reactions in Sprague-Dawley (SD) rats were quantitatively studied by analyzing electroencephalogram (EEG) changes induced by overexposure to 35 GHz millimeter waves. The relative changes in average energy of the EEG and its wavelet decompositions were used for extracting the stress reaction indicators. Incident average power densities (IAPDs) of 35 GHz millimeter waves from 0.5 W cm(-2) to 7.5 W cm(-2) were employed to investigate the relation between irradiation dose and the stress reactions in the rats. Different stress reaction periods evoked by irradiation were quantitatively evaluated by EEG results. The results illustrate that stress reactions are more intense during the first part of the irradiation than during the later part. The skin temperature increase produced by millimeter wave irradiation is the principle reason for stress reactions and skin injuries. As expected, at the higher levels of irradiation, the reaction time decreases and the reaction intensity increases.

  7. The gyrotron - a natural source of high-power orbital angular momentum millimeter-wave beams

    NASA Astrophysics Data System (ADS)

    Thumm, M.; Sawant, A.; Choe, M. S.; Choi, E. M.

    2017-08-01

    Orbital angular momentum (OAM) of electromagnetic-wave beams provides further diversity to multiplexing in wireless communication. The present report shows that higher-order mode gyrotrons are natural sources of high-power OAM millimeter (mm) wave beams. The well-defined OAM of their rotating cavity modes operating at near cutoff frequency has been derived by photonic and electromagnetic wave approaches.

  8. Efficient millimeter wave 1140 GHz/ diode for harmonic power generation

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Epitaxial gallium arsenide diode junction formed in a crossed waveguide structure operates as a variable reactance harmonic generator. This varactor diode can generate power efficiently in the low-millimeter wavelength.

  9. Passive millimeter-wave camera with interferometric processing

    NASA Astrophysics Data System (ADS)

    Nohmi, Hitoshi; Ohnishi, Seiki; Kujubu, Osamu

    2006-05-01

    A proto-type passive millimeter-wave (MMW) camera with interferometric processing has been developed. The purpose is to confirm the feasibility of the interferometric MMW camera and to study the characteristics of MMW images. In this paper, the principle and the feature of the interferometric MMW camera is described. Also, the hardware configuration and the image processing algorithm are presented. This proto-type camera is comprised of the minimum configuration as an interferometric imager which consists of two sets of a W-band front end with a horn antenna, a receiver, and an A/D converter, a high-speed processing hardware, and a computer. The position of these two antennas with W-band front-end moves on the precision linear slider in horizontal and vertical axis. The coherently amplified two channel signals are digitized and processed in the hardware processor. The process is comprised of phase error compensation, correlation of all combination of each axis data, and integration to improve the signal to noise ratio. The computer input the integrated data to make an image by matched filter processing. The integration time is from 1mS to 10S depending on required integration gain. The maximum synthesized antenna aperture size is 1m for horizontal axis and 50cm for vertical axis. Because it takes certain time to receive by the moving antennas, only the targets without motion are imaged by this proto-type camera. The processed images will be shown. Also, future plan for a real-time camera using this technique is presented.

  10. Millimeter-wave electronically scanned reflectarray optimization and analysis

    NASA Astrophysics Data System (ADS)

    Hedden, Abigail S.; Dietlein, Charles R.; Wikner, David A.

    2012-06-01

    The development of millimeter-wave scanning reflectarrays and phased arrays provides an important path to enabling electronic scanning capabilities at high frequencies. This technology could be used to eliminate the mechanical scanners that are currently used with radar imaging systems. In this work, we analyze properties of wafer-scale two-dimensional rectangular lattice arrays that can be used with a confocal imager for 220 GHz electronic scanning of meter-sized fields of regard at 50 m. Applications include covert imaging of hidden anomalies. We examine tradeoffs between overall system size and array complexity and analyze properties of reflectarrays compatible with a system design that was chosen based on these considerations. The effects of phase quantization are considered in detail for arrays with 1- and 2- bit phase shifters and the results are compared in terms of impacts to image quality. Beam pointing accuracy, main beam energy fraction, and the number and intensity of quantization lobes that appear over the scan ranges of interest are compared. Our results indicate that arrays with 1- and 2-bit phase quantization achieve similar main beam energy efficiencies over the desired scan range. Without restricting the scan range, 1-bit phase quantization is insufficient, resulting in maximum errors that are comparable to the required minimum scan angle. Two-bit phase quantization is preferable, resulting in pointing angle errors of at most 15 % of the diffraction-limited beam-size. Both 1- and 2-bit phase quantization cases result in lobes appearing above our threshold, indicating that spurious returns are a problem that will require further attention.

  11. Millimeter-wave molecular line observations of the Tornado nebula

    SciTech Connect

    Sakai, D.; Oka, T.; Tanaka, K.; Matsumura, S.; Miura, K.; Takekawa, S.

    2014-08-10

    We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15' × 15' area was mapped in the J = 1-0 lines of CO, {sup 13}CO, and HCO{sup +} with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V{sub LSR} = –14 km s{sup –1} and +5 km s{sup –1}. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado 'head' in the –14 km s{sup –1} cloud, also suggesting the interaction. Virial analysis shows that the +5 km s{sup –1} cloud is more tightly bound by self-gravity than the –14 km s{sup –1} cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s{sup –1} cloud collided into the –14 km s{sup –1} cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

  12. Millimeter-wave nondestructive evaluation of pavement conditions

    NASA Astrophysics Data System (ADS)

    Vines-Cavanau, David; Busuioc, Dan; Birken, Ralf; Wang, Ming

    2012-04-01

    The United States is suffering from an aging civil infrastructure crisis. Key to recovery are rapid inspection technologies like that being investigated by the VOTERS project (Versatile Onboard Traffic Embedded Roaming Sensors), which aims to outfit ordinary road vehicles with compact low-cost hardware that enables them to rapidly assess and report the condition of roadways and bridge decks free of driver interaction. A key piece of hardware, and the focus of this paper, is a 24 GHz millimeter-wave radar system that measures the reflectivity of pavement surfaces. To account for the variability of real-world driving, such as changes in height, angle, speed, and temperature, a sensor fusion approach is used that corrects MWR measurements based on data from four additional sensors. The corrected MWR measurements are expected to be useful for various characterization applications, including: material type; deterioration such as cracks and potholes; and surface coverage conditions such as dry, wet, oil, water, and ice. Success at each of these applications is an important step towards achieving the VOTERS objective, however, this paper focuses on surface coverage, as whatever covers the driving surface will be most apparent to the MWR sensor and if not accounted for could significantly limit the accuracy of other applications. Contributions of the paper include findings from static lab tests, which validate the approach and show the effects of height and angle. Further contributions come from lab and in-field dynamic tests, which show the effects of speed and demonstrate that the MWR approach is accurate under city driving conditions.

  13. The Detectability of Millimeter-wave Molecular Rotational Transitions

    NASA Astrophysics Data System (ADS)

    Liszt, Harvey S.; Pety, Jerome

    2016-06-01

    Elaborating on a formalism that was first expressed some 40 years ago, we consider the brightness of low-lying millimeter-wave rotational lines of strongly polar molecules at the threshold of detectability. We derive a simple expression relating the brightness to the line-of-sight integral of the product of the total gas and molecular number densities and a suitably defined temperature-dependent excitation rate into the upper level of the transition. Detectability of a line is contingent only on the ability of a molecule to channel enough of the ambient thermal energy into the line, and the excitation can be computed in bulk by summing over rates without solving the multi-level rate equations, or computing optical depths and excitation temperatures. Results for {{HCO}}+, HNC, and CS are compared with escape-probability solutions of the rate equations using closed-form expressions for the expected range of validity of our ansatz, with the result that gas number densities as high as {10}4 {{{cm}}}-3 or optical depths as high as 100 can be accommodated in some cases. For densities below a well-defined upper bound, the range of validity of the discussion can be cast as an upper bound on the line brightness which is 0.3 K for the J = 1-0 lines and 0.8-1.7 K for the J = 2-1 lines of these species. The discussion casts new light on the interpretation of line brightnesses under conditions of weak excitation, simplifies derivation of physical parameters, and eliminates the need to construct grids of numerical solutions of the rate equations.

  14. Peering inside microplasmas sustained by microwaves, millimeter waves and beyond

    NASA Astrophysics Data System (ADS)

    Hopwood, Jeffrey

    2016-09-01

    Atmospheric microplasmas are experimentally investigated over a range of excitation frequency from 0.5 to 12 GHz. A validated fluid model correctly predicts the measured electron density in this band of operation. This model is then extended to predict plasma behavior up to 0.4 THz. At constant power (0.25 W), the central electron density increases to 5x1014 cm-3 as the microwave frequency increases toward the electron energy dissipation frequency of 5 GHz (in argon). Above 5 GHz, the argon plasma density remains approximately constant, but the electrode voltage decreases to less than 5 volts in amplitude. This is remarkable in that the microwave potential is less than the excitation potential of argon. In the millimeter wave band, we observe series resonance between the plasma inductance and sheath capacitance at 30 GHz. The parallel resonance results in strong electron oscillation within the microplasma at the position where the electron plasma frequency is equal to the excitation frequency ( 200 GHz). Crossing resonance boundaries changes the nature of the microplasma impedance between capacitive, resistive, and inductive. In addition to linear behavior, we also present models and measurements of microplasma nonlinearity. Nonlinearity generates harmonic plasma currents and is due primarily to dynamic sheath expansion and electron conduction currents. In total, the microplasma provides a rich variety of electromagnetic behaviors that can be incorporated into plasma-reconfigurable metamaterials and photonic crystals. This work was supported by the Air Force Office of Scientific Research under Award No. FA9550-14-10317 with Dr. Mitat Birkan as the program manager.

  15. REMOTE DETECTION OF RADIOACTIVE PLUMES USING MILLIMETER WAVE TECHNOLOGY

    SciTech Connect

    Barnowski, R.; Chien; H.; Gopalsami, N.

    2009-01-01

    The reprocessing of spent nuclear fuel, a common method for manufacturing weapons-grade special nuclear materials, is accompanied by the release of fi ssion products trapped within the fuel. One of these fi ssion products is a radioactive isotope of Krypton (Kr-85); a pure β- emitter with a half-life of 10.72 years. Due to its chemical neutrality and relatively long half life, nearly all of the Kr-85 is released into the surrounding air during reprocessing, resulting in a concentration of Kr-85 near the source that is several orders of magnitude higher than the typical background (atmospheric) concentrations. This high concentration of Kr-85 is accompanied by a proportionately high increase in air ionization due to the release of beta radiation from Kr-85 decay. Millimeter wave (MMW) sensing technology can be used to detect the presence of Kr-85 induced plumes since a high concentration of ions in the air increases the radar cross section due to a combination of atmospheric phenomena. Possible applications for this technology include the remote sensing of reprocessing activities across national borders bolstering global anti-proliferation initiatives. The feasibility of using MMW radar technology to uniquely detect the presence of Kr-85 can be tested using commercial ion generators or sealed radioactive sources in the laboratory. In this paper we describe our work to derive an ion dispersion model that will describe the spatial distribution of ions from Kr-85 and other common lab sources. The types and energies of radiation emitted by isotopes Co-60 and Cs-137 were researched, and these parameters were incorporated into these dispersion models. Our results can be compared with the results of MMW detection experiments in order to quantify the relationship between radar cross section and air ionization as well as to further calibrate the MMW detection equipment.

  16. Microwave/millimeter wave arbitrary waveform generation via ultrafast photonics

    NASA Astrophysics Data System (ADS)

    Weiner, Andrew M.; McKinney, Jason D.; Lin, Ingrid S.

    2005-05-01

    Femtosecond pulse shaping for generating nearly arbitrarily shaped ultrafast optical pulses is now a well-established technology and has been widely adopted for applications ranging from high-speed communications to coherent laser control of chemical reactions. Arbitrary waveform generation (AWG) capabilities for millimeter-wave, microwave and THz electromagnetic signals, however, are quite limited. Commercial radio frequency AWG instrumentation is currently limited to ~2 GHz bandwidth. In this talk we review work at Purdue in which shaped optical pulses are used to drive an optical-to-electrical (O/E) converter. This leverages our femtosecond optical AWG technology to achieve cycle-by-cycle synthesis of arbitrary voltage waveforms in the range between a few GHz and ~1 THz. Such capabilities could open new possibilities for applications in areas such as wireless communications, electronic countermeasures, sensing, and pulsed radar. Recently our work has focused on the range from GHz to tens of GHz. A particular focus has been on the generation of signals appropriate for ultrawideband (UWB) wireless communications using "monocycle" pulses with very large fractional bandwidths. UWB technology provides high immunity to multipath interference, low probability of intercept, and high spatial resolution (for position location). Potential defense applications include tactical sensor networks and RFIF tags for inventory control. Our experiments demonstrate the ability to generate programmable monocycles with spectra that can be tailored to match emission limits and with durations and bandwidths that improve on the mainstream electronic technology. Additional potential applications include predistortion of transmit waveforms in order to precompensate distortions associated with broadband antennas and waveform optimization for enhanced target discrimination in pulsed radar.

  17. Analysis of Rectangular Folded-Waveguide Millimeter-Wave Slow-wave Structures using Conformal Transformations

    NASA Astrophysics Data System (ADS)

    Sumathy, M.; Vinoy, K. J.; Datta, S. K.

    2009-03-01

    An analysis of rectangular folded-waveguide slow-wave structure was developed using conformal mapping technique through Schwarz’s polygon transformation and closed form expressions for the lumped capacitance and inductance per period of the slow-wave structure were derived in terms of the physical dimensions of the structure, incorporating the effects of the beam hole in the lumped parameters. The lumped parameters were subsequently interpreted for obtaining the dispersion and interaction impedance characteristics of the structure. The analysis was benchmarked for two typical millimeter-wave structures, one operating in Ka-band and the other operating in Q-band, against measurement and 3D electromagnetic modeling using MAFIA.

  18. Near field effects of millimeter-wave power transmission for medical applications

    NASA Astrophysics Data System (ADS)

    Yoon, Hargsoon; Song, Kyo D.; Lee, Kunik; Kim, Jaehwan; Choi, Sang H.

    2011-04-01

    An integration of micro devices system and wireless power transmission (WPT) technology offers a great potential to revolutionize current health care devices. The system integration of wireless power transmission devices with smart microsensors is crucial for replacing a power storage devices and miniaturizing wireless biomedical systems. Our research goal is to replace battery power supply with an implantable millimeter-wave rectenna. Recently, a hat system with a small millimeter-wave antenna which can feed millimeter-wave power to thin-film rectenna array embedding Schottky diodes was introduced for neural sensing and stimulation applications. In order to prove the design concept and investigate wireless power coupling efficiency under the system design, near-field wireless power transmission was studied in terms of wave frequency and distance. Also, in this paper, we will present the influence of biological objects to the wireless power transmission, simulating the experimental conditions of human objects for future medical applications.

  19. Linearly Tapered Slot Antenna Radiation Characteristics at Millimeter-Wave Frequencies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1998-01-01

    An endfire travelling wave antenna, such as, a linearly tapered slot antenna (LTSA) is a viable alternative to a patch antenna at millimeter-wave frequencies because of its simple design and ease of fabrication. This paper presents the radiation characteristics of LTSA at higher millimeter-wave frequencies. The measured radiation patterns are observed to be well behaved and symmetric with the main beam in the endfire direction. The measured gain is about 10 dB. The LTSAs have potential wireless applications at 50 GHz, 77 GHz, and 94 GHz.

  20. CdTe-based Light-Controllable Frequency-Selective Photonic Crystal Switch for Millimeter Waves

    DTIC Science & Technology

    2011-09-01

    Centimeter- and Millimeter-Wave Devices,” J. Lightwave Technol., Vol. 17, No. 11, pp. 2025-2031 (1999) 7. A. A. Vikharev, G. G. Denisov , Vl. V . Kocharovskii...S. V . Kuzikov, V . V . Parshin, N. Yu . Peskov, A. N. Stepanov, D. I. Sobolev, and M. Yu . Shmelev, “A High-Speed Quasi- Optical Wave Phase Switch...10-1-3086 Final Report CdTe-based Light-Controllable Frequency-Selective Photonic Crystal Switch for Millimeter Waves V . B

  1. Power and polarization monitor development for high power millimeter-wave.

    PubMed

    Makino, R; Kubo, S; Kobayashi, K; Kobayashi, S; Shimozuma, T; Yoshimura, Y; Igami, H; Takahashi, H; Mutoh, T

    2014-11-01

    A new type monitor of power and polarization states of millimeter-waves has been developed to be installed at a miter-bend, which is a part of transmission lines of millimeter-waves, for electron cyclotron resonance heating on the Large Helical Device. The monitor measures amplitudes and phase difference of the electric field of the two orthogonal polarizations which are needed for calculation of the power and polarization states of waves. The power and phase differences of two orthogonal polarizations were successfully detected simultaneously.

  2. The effect of millimeter waves at the yeast Saccharomyces cerevisiae during heliogeophysical disturbances

    NASA Astrophysics Data System (ADS)

    Rogacheva, Svetlana M.; Babaeva, Milena I.

    2013-02-01

    The isolated and combined effect of heliogeophysical factors and low intensive electromagnetic radiation of millimeter diapason at the metachromasia reaction of the yeast Saccharomyces cerevisiae was studied. It was established that longterm influence of EMR 65 GHz induced changes in the response of cells towards heliogeomagnetic disturbance. On our opinion millimeter waves may reduce the effect of heliogeophysical factors on living organisms because of destabilization of the intracellular water structure.

  3. A high-precision tunable millimeter-wave photonic LO reference for the ALMA telescope

    NASA Astrophysics Data System (ADS)

    Shillue, W.; Grammer, W.; Jacques, C.; Meadows, H.; Castro, J.; Banda, J.; Treacy, R.; Masui, Y.; Brito, R.; Huggard, P.; Ellison, B.; Cliche, J.-F.; Ayotte, S.; Babin, A.; Costin, F.; Latrasse, C.; Pelletier, F.; Picard, M.-J.; Poulin, M.; Poulin, P.

    2013-06-01

    The Atacama Large Millimeter Array is a radio telescope array of 66 antennas designed for high performance scientific imaging, covering a frequency range of 27-950 GHz. Each antenna has a front end with ten receiving bands, and each band has a local oscillator which is synchronized between all antennas. We describe a high precision tunable millimeter-wave photonic local oscillator reference system, which is used as the synchronizing reference for all ten bands on each receiver.

  4. Millimeter-Wave Imaging Technology Advancements for Plasma Diagnostics Applications

    NASA Astrophysics Data System (ADS)

    Kong, Xiangyu

    To realize fusion plant, the very first step is to understand the fundamental physics of materials under fusion conditions, i.e. to understand fusion plasmas. Our research group, Plasma Diagnostics Group, focuses on developing advanced tools for physicists to extract as much information as possible from fusion plasmas at millions degrees. The Electron Cyclotron Emission Imaging (ECEI) diagnostics is a very useful tool invented in this group to study fusion plasma electron temperature and it fluctuations. This dissertation presents millimeter wave imaging technology advances recently developed in this group to improve the ECEI system. New technologies made it more powerful to image and visualize magneto-hydrodynamics (MHD) activities and micro-turbulence in fusion plasmas. Topics of particular emphasis start from development of miniaturized elliptical substrate lens array. This novel substrate lens array replaces the previous generation substrate lens, hyper-hemispherical substrate lens, in terms of geometry. From the optical performance perspective, this substitution not only significantly simplifies the optical system with improved optical coupling, but also enhances the RF/LO coupling efficiency. By the benefit of the mini lens focusing properties, a wideband dual-dipole antenna array is carefully designed and developed. The new antenna array is optimized simultaneously for receiving both RF and LO, with sharp radiation patterns, low side-lobe levels, and less crosstalk between adjacent antennas. In addition, a high frequency antenna is also developed, which extends the frequency limit from 145 GHz to 220 GHz. This type of antenna will be used on high field operation tokamaks with toroidal fields in excess of 3 Tesla. Another important technology advance is so-called extended bandwidth double down-conversion electronics. This new electronics extends the instantaneous IF coverage from 2 to 9.2 GHz to 2 to 16.4 GHz. From the plasma point of view, it means that the

  5. Microwave and millimeter-wave interaction with terrain

    NASA Astrophysics Data System (ADS)

    Du, Yang

    To develop better understanding of the scattering mechanisms underlying microwave and millimeter wave (MMW) interaction with terrain, it is imperative to construct an extensive database of microwave and MMW measurements, and to develop analytical or empirical models to explain the observed features, with a fine balance between modeling rigorousness and flexibility as well as consistency. This thesis contributes to both aspects through several specific contributions. In the case of database construction and enhancement, the contribution entailed a first-of kind extensive experimental characterization of MMW snow backscatter at grazing incidence, as well as the characterization of the forward scattered signal off of terrain surface at MMW. The modeling contributions involved the development of analytical models for several important interactions of microwave and MMW with terrain. Specifically, first, the sensitivity to soil moisture for both active and passive sensors at, L band was evaluated, which showed that the radar and radiometric sensitivities exhibited comparable reductions due to vegetation cover, hence brought to a conclusion a long disputed issue. Second, this study showed that a simple first-order radiative transfer (RT) model, when coupled with high fidelity characterization of scattering parameters as functions of physical parameters, can capture the scattering mechanism for a complex setting such as a soybean-covered rough surface and provide very good prediction results. Third, we showed that mixed conventional RT (CRT) and dense media RT (DMRT) technique can be used to model the angular behavior of dry snow, provided that the disparity inherent in quasi-crystalline-approximation (QCA) for the extinction coefficient and in conventional determination of the phase matrix. To this purpose we proposed an albedo-matching technique and demonstrated its effectiveness. Forth, for MMW backscatter at wet snow, we showed that the underlying thermodynamic process

  6. Millimeter wave case study of operational deployments: retail, airport, military, courthouse, and customs

    NASA Astrophysics Data System (ADS)

    Tryon, Gary V.

    2008-04-01

    In the wake of the September 11, 2001 terrorist attack on America, our security and defense industry was instantly tasked with delivering technologies that could be used to help prevent future terrorist activities. The general public world wide is asking for solutions that will foster a safe society and travel environment. Our best defenses rest in our talents within a free open society to prevent dangerous individuals from boarding planes, entering buildings, courthouses, transportations hubs and military bases with weapons capable of causing damage and bodily harm in the first place. Passive millimeter wave (PMMW) whole body imaging systems are based upon the principle that every physical entity emits, reflects, and/or absorbs electromagnetic energy. The term "passive" means that this approach does not bombard the test subject with energy radiation to further induce the discovery of hidden objects. PMMW whole body imaging systems focus on the human body's natural emission and reflection of millimeter wavelength energy. In physics, "millimeter waves" (MMW) are defined as extremely high-frequency (30-300 GHz) electromagnetic oscillations. On the electromagnetic spectrum these waves are just larger than infrared waves, but smaller than radio waves. The wavelength of a MMW is between 1 millimeter and 10 millimeters. That is approximately the thickness of a large paperclip up to the diameter of an "AAA" battery.

  7. Millimeter wave satellite concepts. Volume 2: Technical report

    NASA Technical Reports Server (NTRS)

    Hilsen, N. B.; Holland, L. D.; Wallace, R. W.; Kelly, D. L.; Thomas, R. R.; Vogler, F. H.

    1979-01-01

    Identification of technologies for millimeter satellite communication systems, and assessment of the relative risks of these technologies, were accomplished through subsystem modeling and link optimization for both point-to-point and broadcast applications. The results, in terms of annual cost per channel to the user from a commercial view point, are described.

  8. Improved Grid-Array Millimeter-Wave Amplifier

    NASA Technical Reports Server (NTRS)

    Rosenberg, James J.; Rutledge, David B.; Smith, R. Peter; Weikle, Robert

    1993-01-01

    Improved grid-array amplifiers operating at millimeter and submillimeter wavelengths developed for use in communications and radar. Feedback suppressed by making input polarizations orthogonal to output polarizations. Amplifier made to oscillate by introducing some feedback. Several grid-array amplifiers concatenated to form high-gain beam-amplifying unit.

  9. Multi-level segmentation of passive millimeter wave images with Gaussian mixture modeling

    NASA Astrophysics Data System (ADS)

    Yeom, Seokwon; Lee, Dong-Su; Son, Jung-Young

    2011-05-01

    Passive millimeter wave imaging is very useful for security applications since it candetect objects concealed under clothing. In this paper,the multi-level segmentation of passive millimeter wave images is presented to detectconcealed objects under clothing. Our passive millimeter wave imaging system is equipped with a Cassegrain dish antenna and a receiver channel operating around 3 mm wavelength. The expectation-maximization algorithm is adopted to cluster pixelson the basis ofa Gaussian mixture model. The multi-level segmentation is investigated with different numbers of clusters in Gaussian mixture distribution. The performance is evaluated by average probability error. Experimentsconfirm that the presented method is able to detect the wood grip as well as metal part of the hand axconcealed under clothing.

  10. Direct Conversion of Free Space Millimeter Waves to Optical Domain by Plasmonic Modulator Antenna.

    PubMed

    Salamin, Yannick; Heni, Wolfgang; Haffner, Christian; Fedoryshyn, Yuriy; Hoessbacher, Claudia; Bonjour, Romain; Zahner, Marco; Hillerkuss, David; Leuchtmann, Pascal; Elder, Delwin L; Dalton, Larry R; Hafner, Christian; Leuthold, Juerg

    2015-12-09

    A scheme for the direct conversion of millimeter and THz waves to optical signals is introduced. The compact device consists of a plasmonic phase modulator that is seamlessly cointegrated with an antenna. Neither high-speed electronics nor electronic amplification is required to drive the modulator. A built-in enhancement of the electric field by a factor of 35,000 enables the direct conversion of millimeter-wave signals to the optical domain. This high enhancement is obtained via a resonant antenna that is directly coupled to an optical field by means of a plasmonic modulator. The suggested concept provides a simple and cost-efficient alternative solution to conventional schemes where millimeter-wave signals are first converted to the electrical domain before being up-converted to the optical domain.

  11. Direct Conversion of Free Space Millimeter Waves to Optical Domain by Plasmonic Modulator Antenna

    PubMed Central

    2015-01-01

    A scheme for the direct conversion of millimeter and THz waves to optical signals is introduced. The compact device consists of a plasmonic phase modulator that is seamlessly cointegrated with an antenna. Neither high-speed electronics nor electronic amplification is required to drive the modulator. A built-in enhancement of the electric field by a factor of 35 000 enables the direct conversion of millimeter-wave signals to the optical domain. This high enhancement is obtained via a resonant antenna that is directly coupled to an optical field by means of a plasmonic modulator. The suggested concept provides a simple and cost-efficient alternative solution to conventional schemes where millimeter-wave signals are first converted to the electrical domain before being up-converted to the optical domain. PMID:26570995

  12. A passive millimeter-wave imaging system for concealed weapons and explosives detection (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Kolinko, Vladimir G.; Lin, Shiow-Hwa; Shek, Alex; Manning, Will; Martin, Chris; Hall, Max; Kirsten, Oskar; Moore, Joshua; Wikner, David A.

    2005-05-01

    This paper describes a passive millimeter-wave image scanner that leverages technologies previously developed for a video-rate passive millimeter-wave camera (PMC) [1, 2]. The imager has a prime focus elliptical frequency scanned antenna operating in the 75-93 GHz millimeter-wave band, a low noise receiver and a vertical beam former that allows the instantaneous capture of 128 pixel (vertical) column images in 1/30th of a second, with 2-3 K sensitivity. Two dimensional images are created by mechanically rotating the antenna, which produces a 128x60 raster image in 2 seconds. By integrating (averaging) images over a longer time period, we have demonstrated a sub-degree temperature resolution. This sensor has proven itself as a low cost tool for studying the potential of W-band passive imaging for various applications.

  13. Large-scale transmission-type multifunctional anisotropic coding metasurfaces in millimeter-wave frequencies

    NASA Astrophysics Data System (ADS)

    Cui, Tie Jun; Wu, Rui Yuan; Wu, Wei; Shi, Chuan Bo; Li, Yun Bo

    2017-10-01

    We propose fast and accurate designs to large-scale and low-profile transmission-type anisotropic coding metasurfaces with multiple functions in the millimeter-wave frequencies based on the antenna-array method. The numerical simulation of an anisotropic coding metasurface with the size of 30λ × 30λ by the proposed method takes only 20 min, which however cannot be realized by commercial software due to huge memory usage in personal computers. To inspect the performance of coding metasurfaces in the millimeter-wave band, the working frequency is chosen as 60 GHz. Based on the convolution operations and holographic theory, the proposed multifunctional anisotropic coding metasurface exhibits different effects excited by y-polarized and x-polarized incidences. This study extends the frequency range of coding metasurfaces, filling the gap between microwave and terahertz bands, and implying promising applications in millimeter-wave communication and imaging.

  14. Millimeter-wave interferometric radiometry for the detection and geolocation of low-power signals

    NASA Astrophysics Data System (ADS)

    Dowgiallo, David J.; Twarog, Elizabeth M.; Rauen, Steve; Peters, Wendy M.; Lazio, T. Joseph; McGlothlin, Norman R.; Helmboldt, Joseph F.; Gaiser, Peter W.

    2011-05-01

    Millimeter wave detection and imaging is becoming increasingly important with the proliferation of hostile, mobile millimeter wave threats from both weapons systems and communication links. Improved force protection, surveillance, and targeting will rely increasingly on the interception, detection, geo-sorting, and the identification of sources, such as point-to point communication systems, missile seekers, precision guided munitions, and fire control radar systems. This paper describes the Naval Research Laboratory's (NRL) demonstration broadband passive millimeter wave (mmW) interferometric imaging system. This Ka-band system will provide a capability for meter-precision geolocation for imaged objects. The interferometer uses a distributed array of 12 antenna elements to synthesize a large aperture. Each antenna is packaged into an individual receiver, from which a baseband signal is recorded. The correlator is software-based, utilizing signal processing techniques for visibilities, and image formation via beamforming methods. This paper presents first results from an interferometer flight campaign.

  15. Combined illumination cylindrical millimeter-wave imaging technique for concealed weapon detection

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2000-07-01

    A novel millimeter-wave imaging technique has been developed for personnel surveillance applications, including the detection of concealed weapons, explosives, drugs, and other contraband material. Millimeter-waves are high-frequency radio waves in the frequency band of 30 - 300 GHz, and pose no health threat to humans at moderate power levels. These waves readily penetrate common clothing materials, and are reflected by the human body and by concealed items. The combined illumination cylindrical imaging concept consists of a vertical, high-resolution, millimeter-wave array of antennas which is scanned in a cylindrical manner about the person under surveillance. Using a computer, the data from this scan is mathematically reconstructed into a series of focused 3D images of the person. After reconstruction, the images are combined into a single high-resolution 3D image of the person under surveillance. This combined image is then rendered using 3D computer graphics techniques. The combined cylindrical illumination is critical as it allows the display of information from all angles. This is necessary because millimeter-waves do not penetrate the body. Ultimately, the images displayed to the operate will be icon-based to protect the privacy of the person being screened. Novel aspects of this technique include the cylindrical scanning concept and the image reconstruction algorithm, which was developed specifically for this imaging system. An engineering prototype based on this cylindrical imaging technique has been fabricated and tested. This work has been sponsored by the Federal Aviation Administration.

  16. Nondestructive Measurement of Sugar Content in Apples by Millimeter-Wave Reflectometry

    NASA Astrophysics Data System (ADS)

    Oda, Makoto; Mase, Atsushi; Uchino, Kiichiro

    2012-02-01

    A millimeter-wave reflectometer has been developed for the nondestructive measurement of the sugar content in apples. The intensity of the reflected wave from fruit was confirmed to depend on the sugar content and temperature by performing reflectometry with a vector network analyzer of aqueous sucrose solutions. Moreover, the developed reflectometer was applied to the sugar content measurement of apples. We obtained a strong, almost linear relationship between the intensity of the reflected wave and the sugar content in apples.

  17. Millimeter And Submillimeter-Wave Integrated Circuits On Quartz

    NASA Technical Reports Server (NTRS)

    Mehdi, Imran; Mazed, Mohammad; Siegel, Peter; Smith, R. Peter

    1995-01-01

    Proposed Quartz substrate Upside-down Integrated Device (QUID) relies on UV-curable adhesive to bond semiconductor with quartz. Integrated circuits including planar GaAs Schottky diodes and passive circuit elements (such as bandpass filters) fabricated on quartz substrates. Circuits designed to operate as mixers in waveguide circuit at millimeter and submillimeter wavelengths. Integrated circuits mechanically more robust, larger, and easier to handle than planar Schottky diode chips. Quartz substrate more suitable for waveguide circuits than GaAs substrate.

  18. Ultra-Wideband Array in PCB for Millimeter-Wave 5G and ISM

    NASA Technical Reports Server (NTRS)

    Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

    2017-01-01

    Next generation 5G mobile architectures will take advantage of the millimeter-wave spectrum to deliver unprecedented bandwidth. Concurrently, there is a need to consolidate numerous disparate allocations into a single, multi-functional array. Existing arrays are either narrow-band, prohibitively expensive or cannot be scaled to these frequencies. In this paper, we present the first ultra-wideband millimeter-wave array to operate across the six 5G and ISM bands spanning 24-71 GHz. Critically, the array is realized using low-cost PCB. The design concept and optimized layout are presented, and fabrication and measurement considerations are discussed.

  19. Characteristics of millimeter wave microstrip antennas with left-handed materials substrates

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Xie, Yong-Jun; Wang, Peng; Li, Lei

    2006-08-01

    Millimeter wave microstrip antennas with left-handed materials substrates are studied with method of moments. Discrete complex image method is extended to the computation of Green's function in microstrip circuits with left-handed materials substrates. It is shown that this kind of antennas will achieve similar radiation patterns to the ones of conventional millimeter wave microstrip antennas in some cases, and can obtain radiation patterns characteristic of narrow main lobes with low elevation angles in other cases. Potential applications for directive antennas with these unusual radiation patterns of this kind of antennas are proposed.

  20. Array designs for amplitude and phase control of millimeter-wave beams

    NASA Astrophysics Data System (ADS)

    Sjogren, L. B.; Liu, H.-X. L.; Qin, X.-H.; Domier, C. W.; Luhmann, N. C., Jr.

    1993-08-01

    New array design concepts are described for the phase and amplitude control of millimeter and submillimeter-wave beams. Phase shifter array designs providing increased phase range and wider bandwidth are described. Techniques involving the integration of gain-producing elements as well as tuning elements on a single array are proposed for application to high-performance beam control and beam shaping. These concepts should facilitate the further development of quasi-optical solid state device-based arrays for application to millimeter-wave electronic systems.

  1. Twenty and thirty GHz millimeter wave experiments with the ATS-6 satellite

    NASA Technical Reports Server (NTRS)

    Ippolito, L. J. (Compiler)

    1975-01-01

    The ATS-6 millimeter wave experiment, provided the first direct measurements of 20 and 30 GHz earth-space links from an orbiting satellite. Studies at eleven locations in the continental United States were directed at an evaluation of rain attenuation effects, scintillations, depolarization, site diversity, coherence bandwidth, and analog and digital communications techniques. In addition to direct measurements on the 20 and 30 GHz links, methods of attenuation prediction with radars, rain gages, and radiometers were developed and compared with the directly measured attenuation. Initial data results of the ATS-6 millimeter wave experiment from the major participating organizations are presented.

  2. Conversion loss and noise of microwave and millimeter-wave mixers. I - Theory. II - Experiment

    NASA Technical Reports Server (NTRS)

    Held, D. N.; Kerr, A. R.

    1978-01-01

    The conversion loss and noise of microwave and millimeter-wave mixers are analyzed. Nonlinear capacitance, arbitrary embedding impedances, as well as shot, thermal and scattering noise arising in the diode, figure in the analysis. The anomalous mixer noise noted in millimeter-wave mixers by Kerr (1975) is shown to be explainable in terms of the correlation of down-converted components of the time-varying shot noise. A digital computer analysis of the conversion loss, noise, and output impedance of an 80-120-GHz mixer is also conducted.

  3. [Frequency dependence of heating of human skin exposed to millimeter waves].

    PubMed

    Alekseev, S I; Ziskin, M S; Fesenko, E E

    2012-01-01

    In this paper we studied experimentally the frequency dependence of heating of human skin exposed to millimeter waves. Theoretical modeling of obtained data was performed using the hybrid bio-heat equation. It was found that the skin heating and SAR increased with increasing the exposure frequency. The frequency dependence of heating was entirely resulted from that of reflection from the skin. Unlike temperature, the frequency dependence of the SAR was due to the increased absorption of millimeter wave energy within the thin surface layer of the skin.

  4. Optical observations of lensing candidates for millimeter-wave sources

    NASA Astrophysics Data System (ADS)

    Blackman, Ryan; Hughes, J. P.

    2014-01-01

    The field of observational cosmology has taken great strides forward with the development of large aperture, ground-based telescopes that can perform large area surveys in millimeter wavelengths, such as the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT). These instruments have provided astronomers with a new window on the distant universe, from the Cosmic Microwave Background to more nearby active galaxies and dusty star forming galaxies. Recently it was found that a significant subset of the millimeter sources discovered in the new surveys are magnified by foreground galaxies or galaxy clusters acting as gravitational lenses. Therefore, finding and measuring the properties of these lenses is an important aspect of millimeter observing, and a critical step is to obtain their spectroscopic redshifts. We identified 6 lensing candidates for sources observed in an SPT survey using optical imaging data from the Blanco 4-meter telescope. These were then targeted for spectroscopic observations using the Southern African Large Telescope (SALT) from late 2011 to early 2013. From these data we were able to determine the redshift of each candidate, obtaining a range of values from z=0.14 to z=0.80. This project was funded by a grant from the National Science Foundation (PHY-1263280) under the Research Experiences for Undergraduates (REU) program to Rutgers University.

  5. Third International Kharkov Symposium "Physics and Engineering of Millimeter and Submillimeter Waves" MSMW󈨦 Symposium Proceedings, Volume 1,

    DTIC Science & Technology

    1998-09-01

    1 Jf» Third International Kharkov Symposium "Physics and Engineering of Millimeter and Submillimeter Waves" Kharkov, Ukraine September 15-17...34PHYSICS AND ENGINEERING OF MILLIMETER AND SUBMILLIMETER WAVES" MSMW󈨦 Symposium Volume 1 Kharkov, Ukraine September 15-17,1998 DISTRIBUTION...STATEMENT A Approved for Public Release Distribution Unlimited THIRD INTERNATIONAL KHARKOV SYMPOSIUM "PHYSICS AND ENGINEERING OF MILLIMETER AND

  6. Millimeter wave radiation induces apoptosis via affecting the ratio of Bax/Bcl-2 in SW1353 human chondrosarcoma cells.

    PubMed

    Li, Xihai; Ye, Hongzhi; Cai, Liangliang; Yu, Fangrong; Chen, Wenlie; Lin, Ruhui; Zheng, Chunsong; Xu, Huifeng; Ye, Jinxia; Wu, Guangwen; Liu, Xianxiang

    2012-03-01

    The efficacy and safety of millimeter wave radiation has been proven for various types of malignant tumors. However, the mechanisms underlying effects of millimeter wave radiation on apoptosis are still unclear. The present study was undertaken to examine the effects of millimeter wave radiation on cell apoptosis and mitochondrial membrane potential, and to determine the molecular mechanism of millimeter wave radiation-induced apoptosis by investigating the expression of Bcl-2 family proteins (Bcl-2, Bax), caspase-9 and caspase-3 in SW1353 cells. We found that millimeter wave radiation suppressed the viability of SW1353 cells, demonstrating that millimeter wave radiation induced cell apoptosis and reduced cell viability in a time-dependent manner. Furthermore, we observed that treatment of cells with millimeter wave radiation significantly induced loss of mitochondrial membrane potential, upregulated proapoptotic Bax, caspase-9 and caspase-3, but did not significantly change levels of antiapoptotic Bcl-2. These data suggested that millimeter wave radiation may induce apoptosis via affecting the ratio of Bax/Bcl-2 in SW1353 cells.

  7. Equivalent Circuit Analysis of Serpentine Folded-waveguide Slow-wave Structures for Millimeter-wave Traveling-wave Tubes

    NASA Astrophysics Data System (ADS)

    Sumathy, M.; Vinoy, K. J.; Datta, S. K.

    2009-02-01

    A simple equivalent circuit model for the analysis of dispersion and interaction impedance characteristics of serpentine folded-waveguide slow-wave structure was developed by considering the straight and curved portions of structure supporting the dominant TE 10-mode of the rectangular waveguide. Expressions for the lumped capacitance and inductance per period of the slow-wave structure were derived in terms of the physical dimensions of the structure, incorporating the effects of the beam-hole in the lumped parameters. The lumped parameters were subsequently interpreted for obtaining the dispersion and interaction impedance characteristics of the structure. The analysis was simple yet accurate in predicting the dispersion and interaction impedance behaviour at millimeter-wave frequencies. The analysis was benchmarked against measurement as well as with 3D electromagnetic modeling using MAFIA for two typical slow-wave structures (one at the Ka-band and the other at the W-band) and close agreement observed.

  8. A high power Ka band millimeter wave generator with low guiding magnetic field

    SciTech Connect

    Zhu Jun; Shu Ting; Zhang Jun; Li Guolin; Zhang Zehai

    2010-08-15

    A slow wave type gigawatt millimeter wave generator is proposed in this paper. In order to increase power capacity, overmoded slow wave structures (SWSs) with larger diameter have been used. Taking advantage of the ''surface wave'' property of overmoded SWSs, the TM{sub 01} mode can be selected to be the operating mode. Calculations have also been carried out to choose a proper low operating magnetic field strength, and it agrees with particle in cell (PIC) simulations. Main structure parameters of the device are optimized by PIC simulations. A typical simulation result is that, at the beam parameters of 600 keV and 5.05 kA, and guiding magnetic field of 0.85 T, a Ka band millimeter wave with an output power of 1.05 GW is generated, yielding a conversion efficiency of about 35%.

  9. Active millimeter-wave imaging system for material analysis and object detection

    NASA Astrophysics Data System (ADS)

    Zech, Christian; Hülsmann, Axel; Kallfass, Ingmar; Tessmann, Axel; Zink, Martin; Schlechtweg, Michael; Leuther, Arnulf; Ambacher, Oliver

    2011-11-01

    The use of millimeter-waves for imaging purposes is becoming increasingly important, as millimeter-waves can penetrate most clothing and packaging materials, so that the detector does not require physical contact with the object. This will offer a view to the hidden content of e.g. packets or bags without the need to open them, whereby packaging and content will not be damaged. Nowadays X-ray is used, but as the millimeter-wave quantum energy is far below the ionization energy, it is less harmful for the human health. In this paper we report an active millimeter-wave imaging tomograph for material analysis and concealed object detection purposes. The system is build using in-house W-band components. The object is illuminated with low-power millimeter-waves in the frequency range between 89 and 96GHz; mirrors are used to guide and focus the beam. The object is moved through the focus point to scan the object pixel by pixel. Depending on the actual material some parts of the waves are reflected, the other parts penetrate the object. A single-antenna transmit and receive module is used for illumination and measurement of the material-specific reflected power. A second receiver module is used to measure the transmitted wave. All information is processed for amplitude and phase images by a computer algorithm. The system can be used for security, such as detecting concealed weapons, explosives or contrabands at airports and other safety areas, but also quality assurance applications, e.g. during production to detect defects. Some imaging results will be presented in this paper.

  10. The millimeter wave super-Schottky diode detector

    NASA Technical Reports Server (NTRS)

    Silver, A. H.; Pedersen, R. J.; Mccoll, M.; Dickman, R. L.; Wilson, W. J.

    1981-01-01

    The 31 and 92 GHz measurements of the superconductor-Schottky diode extended to millimeter wavelengths by a redesign of the semiconductor interface are reported. Diodes were fabricated by pulse electroplating Pb on 2 x 10 to the 19th/cu cm p-Ga-As etched with HCl; a thin Au overplate is deposited to protect the Pb film from degradation and to improve its lifetime. The noise performance was almost ideal at 31 and 92 GHz; it was concluded that this diode is a quantum-limited-detector at 31 GHz, with excessive parasitic losses at 92 GHz.

  11. Millimeter wave satellite communication studies. Results of the 1981 propagation modeling effort

    NASA Technical Reports Server (NTRS)

    Stutzman, W. L.; Tsolakis, A.; Dishman, W. K.

    1982-01-01

    Theoretical modeling associated with rain effects on millimeter wave propagation is detailed. Three areas of work are discussed. A simple model for prediction of rain attenuation is developed and evaluated. A method for computing scattering from single rain drops is presented. A complete multiple scattering model is described which permits accurate calculation of the effects on dual polarized signals passing through rain.

  12. Millimeter wave tokamak heating and current drive with a high power free electron laser

    SciTech Connect

    Thomassen, K.I.

    1987-01-01

    Experiments on microwave generation using a free electron laser (FEL) have shown this to be an efficient way to generate millimeter wave power in short, intense pulses. Short pulse FEL's have several advantages that make them attractive for application to ECR heating of tokamak fusion reactors. This paper reports on plans made to demonstrate the technology at the Microwave Tokamak Experiment (MTX) Facility.

  13. An optimized forward-coupling microstrip hybrid for millimeter-wave circuits

    NASA Astrophysics Data System (ADS)

    Ikalainen, Pertti

    1990-03-01

    A forward-coupling microstrip hybrid with optimized coupling variation is described. The advantages of the new structure are its suitability for use at millimeter waves, high directivity, and relaxed fabrication tolerance. Experimental results from a 36-GHz coupler are presented.

  14. New Measurements and Assignments in the Millimeter-Wave Spectrum of CD 3OH

    NASA Astrophysics Data System (ADS)

    Predoi-Cross, Adriana; Xu, Li-Hong; Walsh, Matthew S.; Lees, Ronald M.; Winnewisser, Manfred; Lichau, Holger

    1998-03-01

    The ground state rotational spectrum of CD3OH has been revisited in the millimeter-wave range. A total of 216 transition frequencies have been measured and assigned in the 117-179 GHz spectral range, including about 40 transitions previously reported. The spectrum was recorded at the Justus-Liebig University in Gießen, Germany using a frequency modulated millimeter-wave spectrometer. The assignments for the CD3OH transitions were predicted based on energy levels calculated using preliminary results of the global fit of microwave, millimeter-wave, and far-infrared data of Walshet al.(Paper FC04 presented at the 52nd International Symposium of Molecular Spectroscopy, Columbus, OH, 1997). The new measurements have substantially enlarged the accurate millimeter-wave component of the data set available for the global fit and have allowed Walshet al.to obtain significant improvement in the CD3OH molecular parameters (J. Mol. Spectrosc.188,85-93, 1998). The low residuals between observed and calculated frequencies highlight the quality of the global fit results.

  15. Continuous millimeter-wave radiation has no effect on lipid peroxidation in liposomes

    SciTech Connect

    Logani, M.K.; Ziskin, M.C.

    1996-02-01

    The effect of millimeter waves on lipid peroxidation was studied in the presence and absence of melanin. Irradiation of liposomes with continuous millimeter electromagnetic waves at frequencies of 53.6, 61.2 and 78.2 GHz and incident power densities of 10, 1 and 500 mW/cm{sup 2}, respectively, did not show an enhancement in the formation of lipid peroxides compared to unirradiated samples. Liposomes exposed to 254 nm UVC radiation at 0.32 mW/cm{sup 2} and 302 nm UVB radiation at 1.12 mW/cm{sup 2} served as positive controls. No increment in the formation of lipid peroxides was observed when irradiation of liposomes was carried out in the presence of ADP-Fe{sup +3} and EDTA-Fe{sup +3}. Direct irradiation of melanin with millimeter waves did not exhibit an increased formation of superoxide or hydrogen peroxide. The present results indicate that millimeter waves of the above frequencies and intensities do not cause lipid peroxidation in liposomal membranes. 19 refs., 2 figs., 1 tab.

  16. Effects of millimeter-wave electromagnetic exposure on the morphology and function of human cryopreserved spermatozoa.

    PubMed

    Volkova, N A; Pavlovich, E V; Gapon, A A; Nikolov, O T

    2014-09-01

    Exposure of human cryopreserved spermatozoa to millimeter-wave electromagnetic radiation of 0.03 mW/cm2 density for 5 min in normozoospermia and for 15 min in asthenozoospermia lead to increase of the fraction of mobile spermatozoa without impairing the membrane integrity and nuclear chromatin status and without apoptosis generation.

  17. Millimeter wave satellite communication studies. Results of the 1981 propagation modeling effort

    NASA Astrophysics Data System (ADS)

    Stutzman, W. L.; Tsolakis, A.; Dishman, W. K.

    1982-12-01

    Theoretical modeling associated with rain effects on millimeter wave propagation is detailed. Three areas of work are discussed. A simple model for prediction of rain attenuation is developed and evaluated. A method for computing scattering from single rain drops is presented. A complete multiple scattering model is described which permits accurate calculation of the effects on dual polarized signals passing through rain.

  18. Millimeter-Wave Measurement of Frozen Hydrometeors during the 2003 Wakasa Bay Field Experiment

    NASA Technical Reports Server (NTRS)

    Kim, Min-Jeong; Chang, Dong-Eon; Weinman, James A.; Wang, J. R.; Tanelli, Simone; Roman, J.; Sekelsky, S.

    2004-01-01

    This study analyzes the millimeter-wave radiometric measurements of frozen hydrometeors during the field experiment that was held in Wakasa bay of Japan in January 29, 2003. The MM5 cloud simulation is employed to provide temperature and humidity profiles for the radiative transfer calculations.

  19. Millimeter-Wave Thermal Analysis Development and Application to GEN IV Reactor Materials

    SciTech Connect

    Wosko, Paul; Sundram, S. K.

    2012-10-16

    New millimeter-wave thermal analysis instrumentation has been developed and studied for characterization of materials required for diverse fuel and structural needs in high temperature reactor environments such as the Next Generation Nuclear Plant (NGNP). A two-receiver 137 GHz system with orthogonal polarizations for anisotropic resolution of material properties has been implemented at MIT. The system was tested with graphite and silicon carbide specimens at temperatures up to 1300 ºC inside an electric furnace. The analytic and hardware basis for active millimeter-wave radiometry of reactor materials at high temperature has been established. Real-time, non contact measurement sensitivity to anisotropic surface emissivity and submillimeter surface displacement was demonstrated. The 137 GHz emissivity of reactor grade graphite (NBG17) from SGL Group was found to be low, ~ 5 %, in the 500 – 1200 °C range and increases by a factor of 2 to 4 with small linear grooves simulating fracturing. The low graphite emissivity would make millimeter-wave active radiometry a sensitive diagnostic of graphite changes due to environmentally induced stress fracturing, swelling, or corrosion. The silicon carbide tested from Ortek, Inc. was found to have a much higher emissivity at 137 GHz of ~90% Thin coatings of silicon carbide on reactor grade graphite supplied by SGL Group were found to be mostly transparent to millimeter-waves, increasing the 137 GHz emissivity of the coated reactor grade graphite to about ~14% at 1250 ºC.

  20. Characteristics of a Teflon Rod Antenna for Millimeter- and Submillimeter-Wave Irradiation on Living Bodies

    NASA Astrophysics Data System (ADS)

    Tatsukawa, Toshiaki; Doi, Akitaka; Teranaka, Masato; Takashima, Hitoshi; Goda, Fuminori; Idehara, Toshitaka; Kanemaki, Tomohiro; Nishizawa, Seiji; Namba, Tunetoyo

    2003-11-01

    The development of a millimeter- and submillimeter-wave catheter for irradiation on living bodies using a Teflon rod dielectric antenna is described. The power sources of electromagnetic wave are an Impatt oscillator (90 GHz, 0.3 W) and a gyrotron (302 GHz, 30 W). Irradiation tests using various Teflon rod dielectric antennas were performed on cow livers, living rats and a cancerous tumor implanted in living mice. Irradiation results were considered by microwave theory and ray optics.

  1. Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    The design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator is presented. The intended applications of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37 to 43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

  2. Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    This paper presents the design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37-43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

  3. Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    This paper presents the design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37 to 43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

  4. Absorption of millimeter waves by human beings and its biological implications

    SciTech Connect

    Gandhi, O.P.; Riazi, A.

    1986-02-01

    With recent advances in millimeter-wave technology, including the availability of high-power sources, in this band, it has become necessary to understand the biological implications of this energy for human beings. This paper gives the millimeter-wave absorption efficiency for the human body with and without clothing. Ninety to ninety-five percent of the incident energy may be absorbed in the skin with dry clothing, with or without an intervening air gap, acting as an impedance transformer. On account of the submillimeter depths of penetration in the skin, superficial SAR's as high as 65-357 W/Kg have been calculated for power density of incident radiation corresponding to the ANSI guideline of 5 mW/cm/sup 2/. Because most of the millimeter-wave absorption is in the region of the cutaneous thermal receptors (0.1-1.0 mm), the sensations of absorbed energy are likely to be similar to those of IR. For the latter, threshold of heat perception is near 0.67 mW/cm/sup 2/, with power densities on the order of 8.7 mW/cm/sup 2/ likely to cause sensations of ''very warm to hot'' with a latency of 1.0 +- 0.6 s. Calculations are made for thresholds of hearing of pulsed millimeter waves. Pulsed energy densities of 143/579 ..mu..J/cm/sup 2/ are obtained for the frequency band 30-300 GHz. These are 8-28 times larger than the threshold for microwaves below 3 GHz. The paper also points to the need for evaluation of ocular effects of millimeter-wave irradiation because of high SAR's in the cornea.

  5. Integrated Wide-Band Millimeter Wave Imaging System

    DTIC Science & Technology

    2007-11-02

    the propagation of EM waves. Its efficiency lies in the ability to propagate EM waves from one plane to another using Fast Fourier Transforms (FFTs...efficiencies, 7 we use 2D FDTD in near field calculations for each diffractive lenses and use 2D Fast Fourier Transform (FFT) to propagate each field...in Figure 8, we mathematically reconstructed a series of near field distribution slices based on Fourier optics theory, e.g., the plane wave angular

  6. Land clutter statistical model for millimeter-wave radar

    NASA Astrophysics Data System (ADS)

    Kulemin, Gennady P.

    2003-08-01

    The main computation relations for determination o MMW radar land clutter statistical characteristics are analyzed. Expressions for normalized RCS determination of different surface types and polarization features of backscattering signals are discussed. Spatial and temporal statistical characteristics of the quadrature components and the amplitudes of scattered signals are analyzed; the influence of spatial characteristics of real land terrain on the quadrature component and amplitude distributions is discussed. It is shown that the amplitude pdf is approximated by the Weibull's law and the distribution of quadrature components is described by the compound Gaussian law. The spatial distributions for different terrain types are presented. As result, the algorithms for radar clutter modeling at millimeter band of radiowaves are obtained taking into consideration the spatial statistics of natural land surface.

  7. Reflective chamber for hardware-in-the-loop simulation of active/passive millimeter wave sensors

    NASA Astrophysics Data System (ADS)

    Sholes, W. J.; Wilsdorf, T. T.

    A unique reflective chamber has been developed at the MICOM Advanced Simulation Center for hardware-in-the-loop simulation for combined active and passive millimeter sensors. This paper describes the reasons for developing such a reflective chamber and provides results of measurement of active reflection levels and radiometric temperatures within the chamber. Utilization of this chamber in a hardware-in-the-loop simulation for a millimeter wave weapon system is described, including the computer equipment and software system for real-time control of the simulator.

  8. Millimeter-wave spectra and variability of bright, compact radio sources

    NASA Technical Reports Server (NTRS)

    Edelson, R. A.

    1987-01-01

    Observations at 2.7 mm and at 1.5 cm were used to study the millimeter spectra and variability of 176 bright, compact radio sources. More than 20 percent of the flat-spectrum sources, but none of the steep-spectrum sources, were seen to vary at 1.5 cm by at least 30 percent over ten months. This is consistent with the hypothesis that flat-spectrum sources are compact and possibly beamed, while steep-spectrum sources are not. These data can also be used to choose sources for VLBI observations and for calibration of millimeter-wave observations.

  9. Design of a Dielectric Rod Waveguide Antenna Array for Millimeter Waves

    NASA Astrophysics Data System (ADS)

    Rivera-Lavado, Alejandro; García-Muñoz, Luis-Enrique; Generalov, Andrey; Lioubtchenko, Dmitri; Abdalmalak, Kerlos-Atia; Llorente-Romano, Sergio; García-Lampérez, Alejandro; Segovia-Vargas, Daniel; Räisänen, Antti V.

    2017-01-01

    In this manuscript, the use of dielectric rod waveguide (DRW) antennas in the millimeter and sub-millimeter wave range is presented as a solution for covering two issues: getting more radiated power and filling a technological gap problem in the terahertz band, namely a fully electronic beam steering. A 4x4 element array working at 100 GHz fed by a rectangular waveguide is manufactured and measured for showing its capabilities. This topology can be used as a cost-affordable alternative to dielectric lenses in photomixer-based terahertz sources.

  10. Understanding the variation in the millimeter-wave emission of Venus

    NASA Technical Reports Server (NTRS)

    Fahd, Antoine K.; Steffes, Paul G.

    1992-01-01

    Recent observations of the millimeter-wave emission from Venus at 112 GHz (2.6 mm) have shown significant variations in the continuum flux emission that may be attributed to the variability in the abundances of absorbing constituents in the Venus atmosphere. Such constituents include gaseous H2SO4, SO2, and liquid sulfuric acid (cloud condensates). Recently, Fahd and Steffes have shown that the effects of liquid H, SO4, and gaseous SO2 cannot completely account for this measured variability in the millimeter-wave emission of Venus. Thus, it is necessary to study the effect of gaseous H2SO4 on the millimeter-wave emission of Venus. This requires knowledge of the millimeter-wavelength (MMW) opacity of gaseous H2SO4, which unfortunately has never been determined for Venus-like conditions. We have measured the opacity of gaseous H2SO4 in a CO2 atmosphere at 550, 570, and 590 K, at 1 and 2 atm total pressure, and at a frequency of 94.1 GHz. Our results, in addition to previous centimeter-wavelength results are used to verify a modeling formalism for calculating the expected opacity of this gaseous mixture at other frequencies. This formalism is incorporated into a radiative transfer model to study the effect of gaseous H2SO4 on the MMW emission of Venus.

  11. Quantum-limited detection of millimeter waves using superconducting tunnel junctions

    SciTech Connect

    Mears, C.A.

    1991-09-01

    The quasiparticle tunneling current in a superconductor-insulator- superconductor (SIS) tunnel junction is highly nonlinear. Such a nonlinearity can be used to mix two millimeter wave signals to produce a signal at a much lower intermediate frequency. We have constructed several millimeter and sub-millimeter wave SIS mixers in order to study high frequency response of the quasiparticle tunneling current and the physics of high frequency mixing. We have made the first measurement of the out-of-phase tunneling currents in an SIS tunnel junction. We have developed a method that allows us to determine the parameters of the high frequency embedding circuit by studying the details of the pumped I-V curve. We have constructed a 80--110 GHz waveguide-based mixer test apparatus that allows us to accurately measure the gain and added noise of the SIS mixer under test. Using extremely high quality tunnel junctions, we have measured an added mixer noise of 0.61 {plus minus} 0.36 quanta, which is within 25 percent of the quantum limit imposed by the Heisenberg uncertainty principle. This measured performance is in excellent agreement with that predicted by Tucker's theory of quantum mixing. We have also studied quasioptically coupled millimeter- and submillimeter-wave mixers using several types of integrated tuning elements. 83 refs.

  12. Quantum-limited detection of millimeter waves using superconducting tunnel junctions

    SciTech Connect

    Mears, C.A.

    1991-09-01

    The quasiparticle tunneling current in a superconductor-insulator- superconductor (SIS) tunnel junction is highly nonlinear. Such a nonlinearity can be used to mix two millimeter wave signals to produce a signal at a much lower intermediate frequency. We have constructed several millimeter and sub-millimeter wave SIS mixers in order to study high frequency response of the quasiparticle tunneling current and the physics of high frequency mixing. We have made the first measurement of the out-of-phase tunneling currents in an SIS tunnel junction. We have developed a method that allows us to determine the parameters of the high frequency embedding circuit by studying the details of the pumped I-V curve. We have constructed a 80--110 GHz waveguide-based mixer test apparatus that allows us to accurately measure the gain and added noise of the SIS mixer under test. Using extremely high quality tunnel junctions, we have measured an added mixer noise of 0.61 {plus_minus} 0.36 quanta, which is within 25 percent of the quantum limit imposed by the Heisenberg uncertainty principle. This measured performance is in excellent agreement with that predicted by Tucker`s theory of quantum mixing. We have also studied quasioptically coupled millimeter- and submillimeter-wave mixers using several types of integrated tuning elements. 83 refs.

  13. Study and interpretation of the millimeter-wave spectrum of Venus

    NASA Technical Reports Server (NTRS)

    Fahd, Antoine K.; Steffes, Paul G.

    1992-01-01

    The effects of the Venus atmospheric constituents on its millimeter wavelength emission are investigated. Specifically, this research describes the methodology and the results of laboratory measurements which are used to calculate the opacity of some of the major absorbers in the Venus atmosphere. The pressure broadened absorption of gaseous SO2/CO2 and gaseous H2SO4/CO2 has been measured at millimeter wavelengths. We have also developed new formalisms for computing the absorptivities of these gases based on our laboratory work. The complex dielectric constant of liquid sulfuric acid has been measured and the expected opacity from the liquid sulfuric acid cloud layer found in the atmosphere of Venus has been evaluated. The partial pressure of gaseous H2SO4 has been measured which results in a more accurate estimate of the dissociation factor of H2SO4. A radiative transfer model has been developed in order to understand how each atmospheric constituent affects the millimeter wave emissions from Venus. Our results from the radiative transfer model are compared with recent observations of the micro-wave and millimeter wave emissions from Venus. Our main conclusion from this work is that gaseous H2SO4 is the most likely cause of the variation in the observed emission from Venus at 112 GHz.

  14. An adjustable RF tuning element for microwave, millimeter wave, and submillimeter wave integrated circuits

    NASA Technical Reports Server (NTRS)

    Lubecke, Victor M.; Mcgrath, William R.; Rutledge, David B.

    1991-01-01

    Planar RF circuits are used in a wide range of applications from 1 GHz to 300 GHz, including radar, communications, commercial RF test instruments, and remote sensing radiometers. These circuits, however, provide only fixed tuning elements. This lack of adjustability puts severe demands on circuit design procedures and materials parameters. We have developed a novel tuning element which can be incorporated into the design of a planar circuit in order to allow active, post-fabrication tuning by varying the electrical length of a coplanar strip transmission line. It consists of a series of thin plates which can slide in unison along the transmission line, and the size and spacing of the plates are designed to provide a large reflection of RF power over a useful frequency bandwidth. Tests of this structure at 1 GHz to 3 Ghz showed that it produced a reflection coefficient greater than 0.90 over a 20 percent bandwidth. A 2 GHz circuit incorporating this tuning element was also tested to demonstrate practical tuning ranges. This structure can be fabricated for frequencies as high as 1000 GHz using existing micromachining techniques. Many commercial applications can benefit from this micromechanical RF tuning element, as it will aid in extending microwave integrated circuit technology into the high millimeter wave and submillimeter wave bands by easing constraints on circuit technology.

  15. Ultrafast millimeter-wave frequency-modulated continuous-wave reflectometry for NSTX

    SciTech Connect

    Kubota, S.; Peebles, W. A.; Nguyen, X. V.; Crocker, N. A.; Roquemore, A. L.

    2006-10-15

    The millimeter-wave frequency-modulated continuous-wave (FM-CW) reflectometer on NSTX is a multichannel system providing electron density profile measurements with a frequency coverage of 13-53 GHz [corresponding O-mode density range of (0.21-3.5)x10{sup 13} cm{sup -3}]. Recently, this system has been modified to allow ultrafast full-band sweeps for repetition intervals down to 10 {mu}s. For this system to function as a fluctuation diagnostic it is crucial to eliminate artifacts in the phase derivative caused by nonlinearities in the frequency sweep; we introduce a simple hardware technique for reducing these artifacts to {approx_equal}0.3%. For NSTX, the additional bandwidth ({<=}100 kHz) greatly enhances the capability of the FM-CW reflectometer as a diagnostic for low frequency magnetohydrodynamics instabilities (e.g., internal kinks, resistive wall modes, neoclassical tearing modes, as well as fast-particle driven fishbones and low frequency toroidal Alfven eigenmodes)

  16. Millimeter-wave concealed weapons detection and through-the-wall imaging systems

    NASA Astrophysics Data System (ADS)

    Huguenin, G. Richard

    1997-02-01

    Millimetrix' millimeter wave passive imaging technology offers the opportunity for rapid and remote detection of metallic and non-metallic weapons, plastic explosives, drugs, and other contraband concealed under multiple layers of clothing without the necessity of a direct physical search. The purely passive imaging technique relies solely on the existing natural emissions from the scene objects, does not expose the person to any man-made radiation, and is therefore completely harmless to the person being observed and to all others in the area. Screening can be done remotely and with as much discretion as the situation requires. The passive imaging approach to the detection of concealed weapons and contraband hidden under people's clothing works well at millimeter wavelengths because of a fortunate convergence of a number of key factors: (1) adequate resolution in a reasonable sensor size; (2) high transparency of virtually all clothing; and (3) the extraordinarily high emissivity of human flesh compared to the vast majority of other materials. Longer (microwave) wavelengths are impractical because of sensor size and resolution issues, and shorter (infrared) wavelengths are impractical because of the poor transparency of most clothing. The ability of millimeter wave emissions to penetrate many common building materials permits the remote observation, using active millimeter wave sensors, of people and other objects within a room from outside of that room. The resulting through-the-wall 'live' video images of people and furnishings will indicate their location, posture, and activity within a room which should be valuable knowledge to Special Operations, SWAT, and other military and law enforcement personnel prior to their entering that room. Millimeter wave radar imaging systems based on passive MillivisionR camera technology are being developed by Millimetrix (and other members of the MIRTAC TRP consortium) for through-the-wall imaging system (TWIS) applications.

  17. Traveling-Wave Tube Amplifier Second Harmonic as Millimeter-Wave Beacon Source for Atmospheric Propagation Studies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    The design and test results of a novel waveguide multimode directional coupler for a CW millimeter-wave satellite beacon source are presented. The coupler separates the second harmonic power from the fundamental output power of a traveling-wave tube amplifier. A potential application of the beacon source is for investigating the atmospheric effects on Q-band (37 to 42 GHz) and VW-band (71 to 76 GHz) satellite-to-ground signals.

  18. Traveling-Wave Tube Amplifier Second Harmonic as Millimeter-Wave Beacon Source for Atmospheric Propagation Studies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    This paper presents the design and test results of a CW millimeter-wave satellite beacon source, based on the second harmonic from a traveling-wave tube amplifier and utilizes a novel waveguide multimode directional coupler. A potential application of the beacon source is for investigating the atmospheric effects on Q-band (37 to 42 GHz) and V/W-band (71 to 76 GHz) satellite-to-ground signals.

  19. Traveling-Wave Tube Amplifier Second Harmonic as Millimeter-Wave Beacon Source for Atmospheric Propagation Studies

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    This paper presents the design and test results of a CW millimeter-wave satellite beacon source, based on the second harmonic from a traveling-wave tube amplifier and utilizes a novel waveguide multimode directional coupler. A potential application of the beacon source is for investigating the atmospheric effects on Q-band (37-42 GHz) and V/W-band (71- 76 GHz) satellite-to-ground signals.

  20. Millimeter-Wave Evolution for 5G Cellular Networks

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Kei; Tran, Gia Khanh; Shimodaira, Hidekazu; Nanba, Shinobu; Sakurai, Toshiaki; Takinami, Koji; Siaud, Isabelle; Strinati, Emilio Calvanese; Capone, Antonio; Karls, Ingolf; Arefi, Reza; Haustein, Thomas

    Triggered by the explosion of mobile traffic, 5G (5th Generation) cellular network requires evolution to increase the system rate 1000 times higher than the current systems in 10 years. Motivated by this common problem, there are several studies to integrate mm-wave access into current cellular networks as multi-band heterogeneous networks to exploit the ultra-wideband aspect of the mm-wave band. The authors of this paper have proposed comprehensive architecture of cellular networks with mm-wave access, where mm-wave small cell basestations and a conventional macro basestation are connected to Centralized-RAN (C-RAN) to effectively operate the system by enabling power efficient seamless handover as well as centralized resource control including dynamic cell structuring to match the limited coverage of mm-wave access with high traffic user locations via user-plane/control-plane splitting. In this paper, to prove the effectiveness of the proposed 5G cellular networks with mm-wave access, system level simulation is conducted by introducing an expected future traffic model, a measurement based mm-wave propagation model, and a centralized cell association algorithm by exploiting the C-RAN architecture. The numerical results show the effectiveness of the proposed network to realize 1000 times higher system rate than the current network in 10 years which is not achieved by the small cells using commonly considered 3.5 GHz band. Furthermore, the paper also gives latest status of mm-wave devices and regulations to show the feasibility of using mm-wave in the 5G systems.

  1. The influence of polarization on millimeter wave propagation through rain. Ph.D Thesis. Interim Report

    NASA Technical Reports Server (NTRS)

    Wiley, P. H.; Bostian, C. W.; Stutzman, W. L.

    1973-01-01

    The influence of polarization on millimeter wave propagation is investigated from both an experimental and a theoretical viewpoint. First, previous theoretical and experimental work relating to the attenuation and depolarization of millimeter waves by rainfall is discussed. Considerable detail is included in the literature review. Next, a theoretical model is developed to predict the cross polarization level during rainfall from the path average rain rate and the scattered field from a single raindrop. Finally, data from the VPI and SU depolarization experiment are presented as verification of the new model, and a comparison is made with other theories and experiments. Aspects of the new model are: (1) spherical rather than plane waves are assumed, (2) the average drop diameter is used rather than a drop size distribution, and (3) it is simple enough so that the effect which changing one or more parameters has on the crosspolarization level is easily seen.

  2. Analysis of Waveform Errors in Millimeter-Wave Lfmcw Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Wang, Wenqin

    2006-11-01

    In remote sensing applications, there is a special interest in the lightweight, cost effective, and high resolution imaging sensors. The combination of linearly frequency modulated continuous wave (LFMCW) technology and synthetic aperture radar (SAR) technique can lead to such a sensor. This paper concentrates on the analysis of waveform errors in millimeter-wave (MMW) LFMCW SAR. The generating scheme of millimeter-wave LFMCW waveforms with phase locked loop (PLL) and direct digital synthesizer (DDS) combined frequency synthesizer is investigated. The impacts of quantization errors, spurs, and frequency nonlinearities are analyzed. Simulation results show that the quality of LFMCW waveforms has a direct influence on the SAR images. Hence a scheme of frequency synthesizer to achieve high performance MMW LFMCW waveform is proposed. This synthesizer driven by a DDS array can adaptive suppress the spurious level without degradation of excellent frequency linearity and fast switching speed.

  3. Electrically optical phase controlling for millimeter wave orbital angular momentum multi-modulation communication

    NASA Astrophysics Data System (ADS)

    Wu, Haotian; Tang, Jin; Yu, Zhenliang; Yi, Jun; Chen, Shuqing; Xiao, Jiangnan; Zhao, Chujun; Li, Ying; Chen, Lin; Wen, Shuangchun

    2017-06-01

    Orbital angular momentum (OAM), an emerging and fascinating degree of freedom, has highlighted an innovation in communication and optical manipulation field. The beams with different OAM state, which manifest as the phase front ;twisting; of electromagnetic waves, are mutually orthogonal, which is exactly what a new freedom applied to practical communication eagers for. Herein, we proposed a novel millimeter-wave OAM modulation technique by electrically optical phase controlling. By modulating OAM and phase of optical-millimeter-wave synchronously, the multi-modulation: quadrature orbital angular momentum modulation (QOM) communication system at W band is structured and simulated, allowing a 50 Gbit/s signal transmitting with bit-error rates less than 10-4. Our work might suggest that OAM could be compounded to more complex multi-modulation signal, and revealed a new insight into OAM based high capacity wireless and radio-over-fiber communication.

  4. Ultra-wide Bandwidth Inter-Chip Interconnects for Heterogeneous Millimeter-Wave and THz Circuits

    NASA Astrophysics Data System (ADS)

    Fay, Patrick; Bernstein, Gary H.; Lu, Tian; Kulick, Jason M.

    2016-09-01

    Heterogeneous chip-to-chip interconnects with low loss and ultra-wide bandwidths have been demonstrated. Coplanar waveguide-based interconnects between GaAs and Si die have been fabricated and characterized and the results compared to expectations from full-wave electromagnetic simulation. Broadband transmission characteristics were obtained, with insertion losses below 0.3 dB at 100 GHz and below 0.8 dB at frequencies up to 220 GHz demonstrated experimentally. The measured return loss exceeded 11.5 dB at all frequencies up to 220 GHz. The interconnects offer low latency, with a measured group delay of 0.69 ps. The measured results are in good agreement with full-wave simulations, indicating that the measured results do not suffer from significant impairments compared to theoretical predictions. The demonstrated interconnects offer an alternative to conventional approaches to millimeter-wave circuit and system integration, by enabling the compact realization of circuits in the microwave, millimeter-wave, sub-millimeter-wave, and THz frequency regimes in heterogeneous device technologies with very low chip-to-chip insertion loss.

  5. Propagation characteristics for millimeter and quasi-millimeter waves by using three Japanese geostationary satellites

    NASA Astrophysics Data System (ADS)

    Hayashi, R.; Furuhama, Y.; Fugono, N.; Otsu, Y.

    1980-11-01

    experiments carried out by using ETS-II, CS, BS and ECS, and propagation characteristics of radio waves mainly above 10 GHz at the main station (Kashima Branch, RRL).

  6. Challenges and Techniques in Measurements of Noise, Cryogenic Noise and Power in Millimeter-Wave and Submillimeter-Wave Amplifiers

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene

    2014-01-01

    We will present the topic of noise measurements, including cryogenic noise measurements, of Monolithic Microwave Integrated Circuit (MMIC) and Sub-Millimeter-Wave Monolithic Microwave Integrated Circuit (S-MMIC) amplifiers, both on-wafer, and interfaced to waveguide modules via coupling probes. We will also present an overview of the state-of-the-art in waveguide probe techniques for packaging amplifier chips, and discuss methods to obtain the lowest loss packaging techniques available to date. Linearity in noise measurements will be discussed, and experimental methods for room temperature and cryogenic noise measurements will be presented. We will also present a discussion of power amplifier measurements for millimeter-wave and submillimeter-wave amplifiers, and the tools and hardware needed for this characterization.

  7. Challenges and Techniques in Measurements of Noise, Cryogenic Noise and Power in Millimeter-Wave and Submillimeter-Wave Amplifiers

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene

    2014-01-01

    We will present the topic of noise measurements, including cryogenic noise measurements, of Monolithic Microwave Integrated Circuit (MMIC) and Sub-Millimeter-Wave Monolithic Microwave Integrated Circuit (S-MMIC) amplifiers, both on-wafer, and interfaced to waveguide modules via coupling probes. We will also present an overview of the state-of-the-art in waveguide probe techniques for packaging amplifier chips, and discuss methods to obtain the lowest loss packaging techniques available to date. Linearity in noise measurements will be discussed, and experimental methods for room temperature and cryogenic noise measurements will be presented. We will also present a discussion of power amplifier measurements for millimeter-wave and submillimeter-wave amplifiers, and the tools and hardware needed for this characterization.

  8. Millimeter-wave radar for brown-out landings using passive imager components

    NASA Astrophysics Data System (ADS)

    Martin, Christopher A.; Kolinko, Vladimir; Lovberg, John A.

    2010-04-01

    A millimeter-wave radar designed for landing helicopters in brown-out conditions is described and data is presented from an initial flight test. The radar operates in a frequency modulated continuous wave architecture, determining range to target by calculating the difference between transmitted and returned frequencies. The millimeter-wave frequency band provides sand and dust penetration and allows for small apertures appropriate for helicopter mounting. This radar also uses a flat panel phased-array receive antenna and phase processor to sample multiple antenna beams simultaneously, an architecture that has previously been successfully used in passive millimeter-wave imaging systems. The radar presents a wide field-of-view image to the operator at a 3 Hz frame rate where range to the ground and obstacles is depicted in grayscale. The flight test showed the radar to be capable of depicting terrain height variations and obstacles such as buildings, vehicles, building materials, and even power lines. Reductions in noise and symbology improvements are necessary developments for a viable landing system.

  9. STUDIES OF MILLIMETER-WAVE ATMOSPHERIC NOISE ABOVE MAUNA KEA

    SciTech Connect

    Sayers, J.; Bock, J. J.; Goldin, A.; Nguyen, H. T.; Golwala, S. R.; Edgington, S. F.; Lange, A. E.; Rossinot, P.; Ade, P. A. R.; Aguirre, J. E.; Haig, D.; Mauskopf, P. D.; Glenn, J.; Laurent, G. T.; Schlaerth, J.

    2010-01-10

    We report measurements of the fluctuations in atmospheric emission (atmospheric noise) above Mauna Kea recorded with Bolocam at 143 and 268 GHz from the Caltech Submillimeter Observatory. The 143 GHz data were collected during a 40 night observing run in late 2003, and the 268 GHz observations were made in early 2004 and early 2005 over a total of 60 nights. Below approx =0.5 Hz, the data time-streams are dominated by atmospheric noise in all observing conditions. The atmospheric noise data are consistent with a Kolmogorov-Taylor turbulence model for a thin wind-driven screen, and the median amplitude of the fluctuations is 280 mK{sup 2} rad{sup -5/3} at 143 GHz and 4000 mK{sup 2} rad{sup -5/3} at 268 GHz. Comparing our results with previous ACBAR data, we find that the normalization of the power spectrum of the atmospheric noise fluctuations is a factor of approx =80 larger above Mauna Kea than above the South Pole at millimeter wavelengths. Most of this difference is due to the fact that the atmosphere above the South Pole is much drier than the atmosphere above Mauna Kea. However, the atmosphere above the South Pole is slightly more stable as well: the fractional fluctuations in the column depth of precipitable water vapor are a factor of approx =sq root2 smaller at the South Pole compared to Mauna Kea. Based on our atmospheric modeling, we developed several algorithms to remove the atmospheric noise, and the best results were achieved when we described the fluctuations using a low-order polynomial in detector position over the 8' field of view. However, even with these algorithms, we were not able to reach photon-background-limited instrument photometer performance at frequencies below approx =0.5 Hz in any observing conditions. We also observed an excess low-frequency noise that is highly correlated between detectors separated by approx<(f/number sign)lambda; this noise appears to be caused by atmospheric fluctuations, but we do not have an adequate model to

  10. NIKA: A millimeter-wave kinetic inductance camera

    NASA Astrophysics Data System (ADS)

    Monfardini, A.; Swenson, L. J.; Bideaud, A.; Désert, F. X.; Yates, S. J. C.; Benoit, A.; Baryshev, A. M.; Baselmans, J. J. A.; Doyle, S.; Klein, B.; Roesch, M.; Tucker, C.; Ade, P.; Calvo, M.; Camus, P.; Giordano, C.; Guesten, R.; Hoffmann, C.; Leclercq, S.; Mauskopf, P.; Schuster, K. F.

    2010-10-01

    Context. Current generation millimeter wavelength detectors suffer from scaling limits imposed by complex cryogenic readout electronics. These instruments typically employ multiplexing ratios well below a hundred. To achieve multiplexing ratios greater than a thousand, it is imperative to investigate technologies that intrinsically incorporate strong multiplexing. One possible solution is the kinetic inductance detector (KID). To assess the potential of this nascent technology, a prototype instrument optimized for the 2 mm atmospheric window was constructed. Known as the Néel IRAM KID Array (NIKA), it has recently been tested at the Institute for Millimetric Radio Astronomy (IRAM) 30-m telescope at Pico Veleta, Spain. Aims: There were four principle research objectives: to determine the practicality of developing a giant array instrument based on KIDs, to measure current in-situ pixel sensitivities, to identify limiting noise sources, and to image both calibration and scientifically-relevant astronomical sources. Methods: The detectors consisted of arrays of high-quality superconducting resonators electromagnetically coupled to a transmission line and operated at ~100 mK. The impedance of the resonators was modulated by incident radiation; two separate arrays were tested to evaluate the efficiency of two unique optical-coupling strategies. The first array consisted of lumped element kinetic inductance detectors (LEKIDs), which have a fully planar design properly shaped to enable direct absorbtion. The second array consisted of antenna-coupled KIDs with individual sapphire microlenses aligned with planar slot antennas. Both detectors utilized a single transmission line along with suitable room-temperature digital electronics for continuous readout. Results: NIKA was successfully tested in October 2009, performing in line with expectations. The measurement resulted in the imaging of a number of sources, including planets, quasars, and galaxies. The images for Mars

  11. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

    NASA Astrophysics Data System (ADS)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

    2017-02-01

    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

  12. Design of a 10-Gb/s satellite downlink at millimeter-wave frequencies

    NASA Astrophysics Data System (ADS)

    Ridgway, Richard W.; Nippa, David W.; Yen, Stephen; Barnum, Thomas J.

    2011-03-01

    System requirements, including carrier frequency, transmitted power and antenna gain are presented for a 10 Gb/s satellite downlink operating at millimeter-wave frequencies. Telecommunications-grade optical components and a high-speed photodiode are used to generate and modulate millimeter-wave carrier frequencies between 90 GHz and 100 GHz at data rates in excess of 10 Gb/s. Experimental results are presented that determine the minimum received power level needed for error-free wireless data transmission. Commercially available W-band power amplifiers are shown to increase the transmitted power level and extend the error-free propagation distance to distances of 10 km. Experimental results and documented atmospheric attenuation values for clouds, fog and rain are used to estimate link budgets for a wireless downlink located on a low-earth-orbiting satellite operating at an altitude of 350 km.

  13. Automatic detection of hidden threats in the TeraSCREEN passive millimeter-wave imaging subsystem

    NASA Astrophysics Data System (ADS)

    Madhogaria, Satish; Schikora, Marek

    2015-05-01

    Passive millimeter-wave imaging systems can play a significant role in security applications. Especially, the detection of hidden threats for border security is a growing field. In this paper we propose a novel approach for automatic threat detection using multiple 94 GHz passive millimeter-wave images. Herein, we discuss four steps essential to solving the task: pre-processing, region-of-interest extraction, threat extraction in each frame and, finally, intelligent fusion of the results from all frames. Besides, showing that the proposed method works reliably for the data-set at hand, we also discuss the advantages of using this method in contrast to state-of-the-art methods.

  14. A Study on Estimating the Aiming Angle Error of Millimeter Wave Radar for Automobile

    NASA Astrophysics Data System (ADS)

    Kuroda, Hiroshi; Okai, Fumihiko; Takano, Kazuaki

    The 76GHz millimeter wave radar has been developed for automotive application such as ACC (Adaptive Cruise Control) and CWS (Collision Warning System). The radar is FSK (Frequency Shift Keying) monopulse type. The radar transmits 2 frequencies in time-duplex manner, and measures distance and relative speed of targets. The monopulse feature detects the azimuth angle of targets without a scanning mechanism. Conventionally a radar unit is aimed mechanically, although self-aiming capability, to detect and correct the aiming angle error automatically, has been required. The new algorithm, which estimates the aiming angle error and vehicle speed sensor error simultaneously, has been proposed and tested. The algorithm is based on the relationship of relative speed and azimuth angle of stationary objects, and the least squares method is used for calculation. The algorithm is applied to measured data of the millimeter wave radar, resulting in aiming angle estimation error of less than 0.6 degree.

  15. Video rate passive millimeter-wave imager utilizing optical upconversion with improved size, weight, and power

    NASA Astrophysics Data System (ADS)

    Martin, Richard D.; Shi, Shouyuan; Zhang, Yifei; Wright, Andrew; Yao, Peng; Shreve, Kevin P.; Schuetz, Christopher A.; Dillon, Thomas E.; Mackrides, Daniel G.; Harrity, Charles E.; Prather, Dennis W.

    2015-05-01

    In this presentation we will discuss the performance and limitations of our 220 channel video rate passive millimeter wave imaging system based on a distributed aperture with optical upconversion architecture. We will cover our efforts to reduce the cost, size, weight, and power (CSWaP) requirements of our next generation imager. To this end, we have developed custom integrated circuit silicon-germanium (SiGe) low noise amplifiers that have been designed to efficiently couple with our high performance lithium niobate upconversion modules. We have also developed millimeter wave packaging and components in multilayer liquid crystal polymer (LCP) substrates which greatly improve the manufacturability of the upconversion modules. These structures include antennas, substrate integrated waveguides, filters, and substrates for InP and SiGe mmW amplifiers.

  16. Research on an artificial dielectric material for millimeter-wave imaging application.

    PubMed

    Wang, Jinbang; Mei, Hanxue; Yang, Kui; Zhao, Lu; Liu, Zhiguo; Zhang, Tao

    2017-03-01

    Material made of artificial molecules fabricated from cage-shaped granules of conductor (CGC) is introduced and its electrical and magnetic characteristics are presented. Its refractive index, calculated using complex relative permittivity and complex relative permeability, is 1.504 at 35 GHz. A two-element lens, consisting of a pair of spherical plano-convex lenses, was designed and fabricated by embedding CGC in poly(methyl methacrylate). The active millimeter-wave imaging system was constructed with the two-element lens by having the curved surfaces face each other. Millimeter-wave (MMW) images of a right trapezoid and twin bars were obtained. The image quality was acceptable, proving that the CGC material has the ability to refract MMWs in MMW imaging and that the ability contrasts with that of some traditional high polymer material.

  17. Real-time passive millimeter-wave imaging from a helicopter platform

    NASA Astrophysics Data System (ADS)

    Martin, Christopher A.; Lovberg, John A.; Clark, Stuart E.; Galliano, Joseph A., Jr.

    2000-07-01

    Real time passive millimeter-wave imaging systems have a wide variety of uses from aircraft navigation and landing in fog to detection of concealed weapons. A useful imaging system for flight platforms requires a large number of pixels and a high frame rate combined with a small antenna volume and a lost cost. We present a millimeter-wave imaging system which uses 32 MMIC low noise amplifiers to display a 60 X 75 pixel image at a 30 Hz frame rate. The system's pupil-plane phased array architecture allows for a relatively thin large aperture antenna. A remotely located processor utilizes microwave guiding circuit boards to perform phase and frequency discrimination on the radiation received by the antenna array.

  18. IR and millimeter waves: Properties, models, and examples of ground target applications

    NASA Astrophysics Data System (ADS)

    Kjellgren, Jan

    1989-08-01

    Literature concerning these objectives was studied. The theory and the background effects are analyzed. Propagation is also addressed. Examples of models of infrared radiometry: PRISM (Physically Reasonable Infrared Signature Model), applied mostly for vehicles; SPACE (Sun, Precipitation, Atmosphere, Clouds, Earth) is used in thermal signatures for military applications. Multispectral image simulation is studied. Concerning multisensors, some applications are reviewed: a counting system for bomber aircraft, and the same for armored cars, based principally on millimeter waves. Some multisensor concepts for propagation problems, such as the identification of remote attack weapons requiring a fitting with three sensors, are given: the laser radar; an infrared sensor for heat data; a sensor of the radiometry in the millimeter wave band.

  19. Passive millimeter-wave imagery of helicopter obstacles in a sand environment

    NASA Astrophysics Data System (ADS)

    Wikner, David A.

    2006-05-01

    Operation of military helicopters in a dusty environment challenges pilots with reduced visibility. Passive millimeter-wave (MMW) imaging has the potential to be used in these environments to image through dust cloud obscurants. The millimeter-wave phenomenology of the sand environment and the obstacles present in that environment are explored in this work. A 93 GHz polarimetric passive MMW imager was used to characterize an obstacle-rich sand environment and the results are presented. It is shown that there is a strong polarimetric signature present for both sand and cinder block between 10 and 30 degrees depression angles. Also shown is the phenomenology associated with shadows on sand. It was determined that berms and ditches can be very difficult to detect using even a sensitive MMW radiometer. The results can be used to model the performance of passive MMW imaging systems in a sandy environment.

  20. The investigation of using 5G millimeter-wave communications links for environmental monitoring

    NASA Astrophysics Data System (ADS)

    Han, Congzheng

    2017-04-01

    There has been significantly increasing recognition that millimeter waves from 30 GHz to 300 GHz as carriers for future 5G cellular networks. This is good for high speed, line-of-sight communication, potentially using very densely deployed infrastructure involving many small cells. High resolution, continuous and accurate monitoring of environmental conditions, such as rainfall and water vapor are of great important to meteorology, hydrology (e.g. flood warning), agriculture, environmental policy (e.g. pollution regulation) and weather forecasting. We have built a 28GHz measurement link at our research institute in central Beijing, China. This work will study the potential of using millimeter wave based wireless links to monitor environmental conditions including rainfall and water vapor.

  1. 36th Annual International Conference on Infrared Millimeter and Terahertz Waves

    SciTech Connect

    Mittleman, Daniel M.

    2011-12-31

    The Major Topic List of the 2011 conference featured a category entitled “IR, millimeter-wave, and THz spectroscopy,” another entitled “Gyro-Oscillators and Amplifiers, Plasma Diagnostics,” and a third called “Free Electron Lasers and Synchrotron Radiation.” Topical areas of interest to meeting participants include millimeter-wave electronics, high-power sources, high-frequency communications systems, and terahertz sensing and imaging, all of which are prominent in the research portfolios of the DOE. The development and study of new materials, components, and systems for use in the IR, THz, and MMW regions of the spectrum are of significant interest as well. a series of technical sessions were organized on the following topics: terahertz metamaterials and plasmonics; imaging techniques and applications; graphene spectroscopy; waveguide concepts; gyrotron science and technology; ultrafast terahertz measurements; and quantum cascade lasers.

  2. Calculation of the line parameters of quasi-planar waveguides for millimeter-wave integrated circuits

    NASA Astrophysics Data System (ADS)

    Schmidt, L.-P.; Menzel, W.

    Mechanical accuracy requirements for waveguide components become more exacting in connection with the use of such components for operation in the millimeter-wave region. Changes in a circuit make it often necessary to construct a new waveguide component. For these reasons, investigations are being conducted with the objective to design millimeter-wave circuits which employ new types of line structures. A number of such structures is considered, taking into account the image guide, the inverted strip image guide, the trapped image guide, the groove guide, the H-guide, the comb guide, the unilateral fin-line, the bilateral fin-line, the antipodal fin-line, the coplanar fin-line, the microstrip line, and the bilateral suspended substrate line. The calculation of the phase coefficients for the waveguides is discussed, giving attention to the use of the equivalent transmission line concept reported by Itoh (1980). The calculation of the line impedance is also considered, and numerical results are presented.

  3. Polarization-based material classification technique using passive millimeter-wave polarimetric imagery.

    PubMed

    Hu, Fei; Cheng, Yayun; Gui, Liangqi; Wu, Liang; Zhang, Xinyi; Peng, Xiaohui; Su, Jinlong

    2016-11-01

    The polarization properties of thermal millimeter-wave emission capture inherent information of objects, e.g., material composition, shape, and surface features. In this paper, a polarization-based material-classification technique using passive millimeter-wave polarimetric imagery is presented. Linear polarization ratio (LPR) is created to be a new feature discriminator that is sensitive to material type and to remove the reflected ambient radiation effect. The LPR characteristics of several common natural and artificial materials are investigated by theoretical and experimental analysis. Based on a priori information about LPR characteristics, the optimal range of incident angle and the classification criterion are discussed. Simulation and measurement results indicate that the presented classification technique is effective for distinguishing between metals and dielectrics. This technique suggests possible applications for outdoor metal target detection in open scenes.

  4. Risks of exposure to ionizing and millimeter-wave radiation from airport whole-body scanners.

    PubMed

    Moulder, John E

    2012-06-01

    Considerable public concern has been expressed around the world about the radiation risks posed by the backscatter (ionizing radiation) and millimeter-wave (nonionizing radiation) whole-body scanners that have been deployed at many airports. The backscatter and millimeter-wave scanners currently deployed in the U.S. almost certainly pose negligible radiation risks if used as intended, but their safety is difficult-to-impossible to prove using publicly accessible data. The scanners are widely disliked and often feared, which is a problem made worse by what appears to be a veil of secrecy that covers their specifications and dosimetry. Therefore, for these and future similar technologies to gain wide acceptance, more openness is needed, as is independent review and regulation. Publicly accessible, and preferably peer-reviewed evidence is needed that the deployed units (not just the prototypes) meet widely-accepted safety standards. It is also critical that risk-perception issues be handled more competently.

  5. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

    PubMed Central

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

    2017-01-01

    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes. PMID:28145513

  6. The imaging algorithm of millimeter-wave forward-looking SAR

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Li, Xingguang; Chen, Dianren

    2017-01-01

    It is studied a new type millimeter-wave forward-looking synthetic aperture radar (SAR) imaging algorithm in this paper, analyzes the imaging principle, echo model of point target is given, deduced the forward-looking synthetic aperture radar RD imaging algorithm, and using MATLAB imaging simulation of point target in 6, a point target simulation results from the peak of 64 * 64 slice contour and azimuth, distance to the envelope of the imaging results were analyzed, found that the distance and azimuth focusing effect is good and the side lobe does not appear distorted and tilted, proved that the system of the millimeter wave synthetic aperture radar imaging of forward-looking , simulation results demonstrate the validity of the system.

  7. Ground station hardware for the ATS-F millimeter wave experiment

    NASA Technical Reports Server (NTRS)

    Duffield, T. L.

    1973-01-01

    The results are presented of a program to design, fabricate, test, and install a primary ATS-F millimeter wave ground receiving station. Propagation parameters at millimeter waves are discussed along with the objective of the overall experiment. A general description is given of the receiving system and its function in the experiment. Typical receiver characteristics are presented which show that the experiment is entirely feasible from a link SNR standpoint. The receiving system hardware designs are discussed with separate treatment given to the propagation and the radiometer receiver designs. The modification and relocation are described of an existing 15-ft antenna to meet the ATS-F requirements. The design of a dual frequency feed subsystem and self calibration equipment is included.

  8. Progress toward a video-rate, passive millimeter-wave imager for brownout mitigation

    NASA Astrophysics Data System (ADS)

    Mackrides, Daniel G.; Schuetz, Christopher A.; Martin, Richard D.; Dillon, Thomas E.; Yao, Peng; Prather, Dennis W.

    2011-05-01

    Currently, brownout is the single largest contributor to military rotary-wing losses. Millimeter-wave radiation penetrates these dust clouds effectively, thus millimeter-wave imaging could provide pilots with valuable situational awareness during hover, takeoff, and landing operations. Herein, we detail efforts towards a passive, video-rate imager for use as a brownout mitigation tool. The imager presented herein uses a distributed-aperture, optically-upconverted architecture that provides real-time, video-rate imagery with minimal size and weight. Specifically, we detail phenomenology measurements in brownout environments, show developments in enabling component technologies, and present results from a 30-element aperiodic array imager that has recently been fabricated.

  9. Glass Melt Emissivity, Viscosity, and Foaming Monitoring with Millimeter-Waves

    SciTech Connect

    Woskov, Paul P.; Sundaram, S.K.; Daniel, William E.; Hadidi, Kamal; Bromberg, Leslie; Miller, Don; Rogers, L.A.

    2003-09-10

    Nuclear waste glass processing efficiencies, improved melter control to anomalies such as foaming, and environmental compliance would be facilitated by the availability of on-line monitoring technologies. It has been shown that the millimeter-wave (MMW) range of the electromagnetic spectrum (0.3-10 mm) is ideally suited to hot melter environments by having wavelengths long enough to penetrate optically obscure views yet short enough to provide spatial resolution with reliable refractory quasi-optical components. A thermal return reflection (TRR) method has been developed that allows a millimeter-wave pyrometer to determine emissivity by returning a portion of the thermal emission as a probe. Melt glass viscosities in the range 20 -2000 Poise and specific gravities have been measured by rates of flow and displacements inside hollow MMW ceramic waveguides immersed into the melts. Glass foaming has been observed by detecting the melt surface swelling followed by the increase in surface emissivity after gases break the surface.

  10. Fiber optic links for microwave/millimeter-wave systems

    NASA Technical Reports Server (NTRS)

    Pan, J. J.

    1989-01-01

    Recent advances in device technology for microwave/mm-wave (M/MMW) analog fiber-optic communication systems are surveyed, with discussion of system parameters, design optimization methods, and hardware selection and manufacturing considerations. Particular attention is given to 1-km-link systems operating at 21, 30, and 12 GHz for satellite-communication, electronic-warfare, and radar applications. The design and fabrication simplicity of direct modulation is weighed against the wide bandwidth, low distortion, and mm-wave and frequency operation advantages of external modulation. Homodyne or heterodyne coherent detection is shown to improve system S/N by 10-20 dB over conventional detection methods. Diagrams, drawings, photographs, and graphs of typical performance data are included.

  11. Fiber optic links for microwave/millimeter-wave systems

    NASA Technical Reports Server (NTRS)

    Pan, J. J.

    1989-01-01

    Recent advances in device technology for microwave/mm-wave (M/MMW) analog fiber-optic communication systems are surveyed, with discussion of system parameters, design optimization methods, and hardware selection and manufacturing considerations. Particular attention is given to 1-km-link systems operating at 21, 30, and 12 GHz for satellite-communication, electronic-warfare, and radar applications. The design and fabrication simplicity of direct modulation is weighed against the wide bandwidth, low distortion, and mm-wave and frequency operation advantages of external modulation. Homodyne or heterodyne coherent detection is shown to improve system S/N by 10-20 dB over conventional detection methods. Diagrams, drawings, photographs, and graphs of typical performance data are included.

  12. Sideband-Separating, Millimeter-Wave Heterodyne Receiver

    NASA Technical Reports Server (NTRS)

    Ward, John S.; Bumble, Bruce; Lee, Karen A.; Kawamura, Jonathan H.; Chattopadhyay, Goutam; Stek, paul; Stek, Paul

    2010-01-01

    Researchers have demonstrated a submillimeter-wave spectrometer that combines extremely broad bandwidth with extremely high sensitivity and spectral resolution to enable future spacecraft to measure the composition of the Earth s troposphere in three dimensions many times per day at spatial resolutions as high as a few kilometers. Microwave limb sounding is a proven remote-sensing technique that measures thermal emission spectra from molecular gases along limb views of the Earth s atmosphere against a cold space background.

  13. Millimeter Wave-based Fatigue Countermeasure Research for Improving Performance and Prolonging Combat Effectiveness of Warfighters

    DTIC Science & Technology

    2011-04-07

    in the Bioelectromagnetics conference held in Seoul, S. Korea in June 2010 and will be presented in the Bioelectromagnetics conference to be held...biological effects of millimeter waves: A review of the literature”, Bioelectromagnetics , vol. 19, pp. 393-413, 1998. [4] A.G. Pakhomov, H.K. Prol, S.P... Bioelectromagnetics , vol. 18, pp. 324-334, 1997. [5] W. Grundler and F. Kaiser, “Experimental evidence for coherent excitations correlated with growth

  14. Millimeter-wave imaging radiometer data processing and development of water vapor retrieval algorithms

    NASA Technical Reports Server (NTRS)

    Chang, L. Aron

    1995-01-01

    This document describes the current status of Millimeter-wave Imaging Radiometer (MIR) data processing and the technical development of the first version of a water vapor retrieval algorithm. The algorithm is being used by NASA/GSFC Microwave Sensors Branch, Laboratory for Hydrospheric Processes. It is capable of a three dimensional mapping of moisture fields using microwave data from airborne sensor of MIR and spaceborne instrument of Special Sensor Microwave/T-2 (SSM/T-2).

  15. Plasma density measurements using FM-CW millimeter wave radar techniques

    SciTech Connect

    Doane, J.L.; Mazzucato, E.; Schmidt, G.L.

    1980-09-01

    Modified FM-CW radar techniques using swept millimeter-wave oscillators are useful for determining when a particular density has been reached in a plasma. Narrowband measurements on the Princeton Large Torus (PLT) demonstrate the suitability of these techniques for controlling high-power auxiliary plasma heating systems. Broadband measurements using these same techniques are proposed, by which the density profile could be determined.

  16. Waveform over fiber: DSP-aided coherent fiber-wireless transmission using millimeter and terahertz waves

    NASA Astrophysics Data System (ADS)

    Kanno, Atsushi; Tien Dat, Pham; Kuri, Toshiaki; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken-ichi

    2015-01-01

    In this paper, we describe seamless networks based on millimeter and terahertz wave radio links using waveform transfer over optical fibers. Coherent optical transceivers with digital signal processing provide transmission impairment compensation in both optical and radio sections, where devices for the signal processing are implemented at edges of the links. Waveforms, which include the modulation formats, the symbol rates, etc., are maintained in the entire links, to reduce transmission latency and energy consumption in the network.

  17. On-Wafer Characterization of Millimeter-Wave Antennas for Wireless Applications

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1998-01-01

    The paper demonstrates a de-embedding technique and a direct on-substrate measurement technique for fast and inexpensive characterization of miniature antennas for wireless applications at millimeter-wave frequencies. The technique is demonstrated by measurements on a tapered slot antenna (TSA). The measured results at Ka-Band frequencies include input impedance, mutual coupling between two TSAs and absolute gain of TSA.

  18. Experimental study of millimeter wave-induced differentiation of bone marrow mesenchymal stem cells into chondrocytes.

    PubMed

    Wu, Guang-Wen; Liu, Xian-Xiang; Wu, Ming-Xia; Zhao, Jin-Yan; Chen, Wen-Lie; Lin, Ru-Hui; Lin, Jiu-Mao

    2009-04-01

    Low power millimeter wave irradiation is widely used in clinical medicine. We describe the effects of this treatment on cultured mesenchymal stem cells (MSCs) and attempted to identify the underlying mechanism. Cells cultured using the whole marrow attachment culture method proliferated dispersedly or in clones. Flow cytometric analyses showed that the MSCs were CD90 positive, but negative for CD45. The negative control group (A) did not express detectable levels of Cbfa1 or Sox9 mRNA at any time point, while cells in the millimeter wave-induced groups (B and C) increasingly expressed both genes after the fourth day post-induction. Statistical analysis showed that starting on the fourth day post-induction, there were very significant differences in the expression of Cbfa1 and Sox9 mRNA between groups A and B as well as A and C at any given time point, between treated groups B and C after identical periods of induction, and within each treated group at different induction times. Transition electron microscopy analysis showed that the rough endoplasmic reticulum of cells in the induced groups was richer and more developed than in cells of the negative control group, and that the shape of cells shifted from long-spindle to near ellipse. Toluidine blue staining revealed heterochromia in the cytoplasm and extracellular matrix of cells in the induced groups, whereas no obvious heterochromia was observed in negative control cells. Induced cells also exhibited positive immunohistochemical staining of collagen II, in contrast to the negative controls. These results show that millimeter wave treatment successfully induced MSCs to differentiate as chondrocytes and the extent of differentiation increased with treatment duration. Our findings suggest that millimeter wave irradiation can be employed as a novel non-drug inducing method for the differentiation of MSCs into chondrocytes.

  19. Millimeter wave radiometer installation in Río Gallegos, southern Argentina

    NASA Astrophysics Data System (ADS)

    Orte, P. F.; Salvador, J.; Wolfram, E.; D'Elia, R.; Nagahama, T.; Kojima, Y.; Tanada, R.; Kuwahara, T.; Morihira, A.; Quel, E.; Mizuno, A.

    2011-05-01

    With the aim of contribution to the study of atmospheric ozone layer, a new sensitive radiometer for atmospheric minor constituents has been installed in the Observatorio Atmosférico de la Patagonia Austral, División LIDAR, CEILAP (CITEDEF-CONICET), in October 2010. This observatory is established in the city of Rio Gallegos (51° 36' S, 69° 19' W), Argentina, close to the spring ozone hole. The millimeter wave radiometer was developed in STEL (Solar Terrestrial Environment Laboratory), Nagoya University, Japan. This passive remote sensing instrument is able to measure the ozone (O3) amount in the high stratosphere and mesosphere continuously and automatically with a high time resolution. The millimeter wave radiometer ozone profiles will be supplemented with the ozone profiles obtained from the DIAL system existent in the observatory. The millimeter wave radiometer is based on the spectral signal detection from the atmosphere due to the molecular rotational transition of molecules under study. The operation is based on a superheterodyne system which uses a Superconductor-Insulator-Superconductor (SIS) mixer receiver operating at 203.6GHz. The SIS mixer junction consists of a sandwich structure of Nb/AlOx/Nb, and is cooled to 4.2K with a closed cycle He-gas refrigerator. Two additional heterodyne-mixed stages are realized with the aim to shift the measured spectral line until a frequency around of 500 MHz. A FFT (Fast Fourier Transform) spectrometer system is used as a back end. The aims of this work are to show the potential of the millimeter wave radiometer installed in the subpolar latitudes close to the polar ozone hole and to present the preliminary result of the first measurements.

  20. Assessment of Possible Hazards Associated with Applications of Millimeter-Wave Systems.

    DTIC Science & Technology

    1981-11-01

    following considerations: a) Effects reported can generally be attributed to changes known to occur upon elevation of temperature (e.g., changes in cell...research, including absorbed dose and temperature regulation. Precautions against false-positive results must be extremely rigid and include...hazards of m-mcrowave radia- tion, 160-172. Polish Medical Publishers, 1974. 19. Edrich, J., and P. C. Hardee. Thermography at millimeter wave lengths

  1. The influence of polarization on millimeter wave propagation through rain. [radio signals

    NASA Technical Reports Server (NTRS)

    Bostian, C. W.; Stutzman, W. L.; Wiley, P. H.; Marshall, R. E.

    1973-01-01

    The measurement and analysis of the depolarization and attenuation that occur when millimeter wave radio signals propagate through rain are described. Progress was made in three major areas: the processing of recorded 1972 data, acquisition and processing of a large amount of 1973 data, and the development of a new theoretical model to predict rain cross polarization and attenuation. Each of these topics is described in detail along with radio frequency system design for cross polarization measurements.

  2. Acute ocular injuries caused by 60-Ghz millimeter-wave exposure.

    PubMed

    Kojima, Masami; Hanazawa, Masahiro; Yamashiro, Yoko; Sasaki, Hiroshi; Watanabe, Soichi; Taki, Masao; Suzuki, Yukihisa; Hirata, Akimasa; Kamimura, Yoshitsugu; Sasaki, Kazuyuki

    2009-09-01

    The goal of this study was to examine the clinical course of 60-GHz millimeter-wave induced damages to the rabbit eye and to report experimental conditions that allow reproducible induction of these injuries. The eyes of pigmented rabbits (total number was 40) were irradiated with 60-GHz millimeter-waves using either a horn antenna or one of two lens antennas (6 and 9 mm diameter; phi6, phi9) Morphological changes were assessed by slit-lamp microscopy. Additional assessments included corneal fluorescein staining, iris fluorescein angiography, and lens epithelium light microscopy. Under the standardized eye-antenna positioning, the three antennas caused varying damages to the eyelids or eyeglobes. The most reproducible injuries without concurrent eyelid edema and corneal desiccation were achieved using the phi6 lens antenna: irradiation for 6 min led to an elevation of the corneal surface temperature (reaching 54.2 +/- 0.9 degrees C) plus corneal edema and epithelial cell loss. Furthermore, mitotic cells appeared in the pupillary area of the lens epithelium. Anterior uveitis also occurred resulting in acute miosis (from 6.6 +/- 1.4 to 2.2 +/- 1.4 mm), an increase in flares (from 6.7 +/- 0.9 to 334.3 +/- 130.8 photons per second), and iris vasodilation or vessel leakage. These findings indicate that the three types of millimeter-wave antennas can cause thermal injuries of varying types and levels. The thermal effects induced by millimeter-waves can apparently penetrate below the surface of the eye.

  3. Millimeter wave radiometry as a means of determining cometary surface and subsurface temperature

    NASA Technical Reports Server (NTRS)

    Hobbs, R. W.; Brandt, J. C.; Maran, S. P.

    1981-01-01

    Thermal emission spectra for a variety of cometary nucleus models were evaluated by a radiative transfer technique adapted from modeling of terrestrial ice and snow fields. It appears that millimeter wave sensing from an interplanetary spacecraft is the most effective available means for distinguishing between alternate models of the nucleus and for evaluating the thermal state of the layer which is below the instantaneous surface where modern theories of the nucleus indicate that sublimation of the cometary volatiles actually occurs.

  4. High-Electron Mobility Graphene Channel Transistors for Millimeter-Wave Applications

    DTIC Science & Technology

    2010-08-31

    introducing this hydrogen treatment process. Figure 3. Change in surface morphology by lithography process: (a) as grown surface of graphenized SiC...characterized. In the FET process, the hydrogen treatment is adapted for the lift-off process in the ohmic contact on graphene . For the gate stack...1 AOARD Grant 09-4074 Final Report High-Electron Mobility Graphene Channel Transistors for Millimeter-Wave Applications Tetsuya Suemitsu

  5. Validation of SCIAMACHY Ozone Column Densities and Profiles Using Ground-Based FTIR and Millimeter Wave Measurements

    NASA Astrophysics Data System (ADS)

    Kopp, G.; Blumenstock, Th.; Brinksma, E.; Eskes, H.; Griesfeller, A.; Hase, F.; Hochschild, G.; Kramer, I.; Mikuteit, S.; Raffalski, U.; van der A, R.

    2004-08-01

    Ground-based FTIR and millimeter wave measurements of the Institute of Meteorology and Climate Research (IMK), Forschungszentrum Karlsruhe, and the Swedish Institute of Space Physics (IRF) are used for validation of SCIAMACHY ozone measurements. FTIR and millimeter wave measurements used for this study were routinely carried out between 2002 and 2004 at IRF at Kiruna, Sweden. In addition IMK carried out millimeter wave measurements on Mount Zugspitze in the Alps in 2003. SCIAMACHY level 2 NRT-products of 2002 are only validated by FTIR data since millimeter wave observations started in late 2002 when SCIAMACHY data were unavailable. For the years 2003 and early 2004 total ozone column abundances retrieved with the TOSOMI algorithm of the Royal Netherlands Meteorological Institute (Koninklijk Nederlands Meteorologisch Instituut, KNMI) are validated by the FTIR and microwave measurements. Finally, ozone limb profiles between July and November 2002 taken from the current SCIA Level 2 Off-Line masterset are validated by the FTIR measurements at Kiruna

  6. ACRF data collection and processing infrastructure.

    SciTech Connect

    Macduff, M. C.; Eagan, R. C.; Decision and Information Sciences; Pacific Northwest National Lab.

    2005-01-01

    Designated a national user facility, the U.S. Department of Energy's (DOE's) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) provides a unique asset for the study of global climate change to the broader national and international research community. It has enormous potential to contribute to a wide range of interdisciplinary science in the areas of meteorology, atmospheric aerosols, hydrology, ecology, oceanography, satellite validation, and to provide potential monitoring sites where remote sensing and modeling related to homeland security can be validated. The primary goals for the ACRF are to (1) provide infrastructure to the scientific community for scientific research pertaining to global climate change and the goals of the ARM Program (Ackerman and Stokes 2003), (2) provide data and information to the scientific community for meeting those goals, and (3) provide education and outreach on the activities and scientific findings that result from ongoing research at the ACRF. The foundation of the ACRF infrastructure is based on the scientific infrastructure created for the ARM Program (DOE 1990). In support of the ARM Program, the ACRF operates three instrumented sites and a mobile facility to provide relevant atmospheric measurements to the ARM Program and to the global scientific community. The goal of the ACRF infrastructure is to deliver these measurement data reliably, quickly, and in a useful format to the scientific community. The basic focus of the infrastructure is to get the data generated by instruments in the field to a central distribution point. The remoteness of the sites and the diversity of the instruments add to the complexity of the solution. Network access to the sites was often limited and significantly impacted options for data flow and the architecture deployed at each location. Because of several iterations and significant work to establish Internet connections at each site, the ACRF has developed an efficient and

  7. Weapon detection using a wideband millimeter-wave linear array imaging technique

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; McMakin, Douglas L.; Collins, H. D.; Hall, Thomas E.

    1994-03-01

    A wideband millimeter-wave imaging technique has been developed by the Pacific Northwest Laboratory (PNL) for the detection of concealed weapons carried by personnel through high- security areas, such as airports. A practical airport system based on this technique should be capable of real-time image frame rate of 10 to 30 frames per second. This technique, similar to an extremely high-resolution radar system, actively probes the target with millimeter-waves and reconstructs an image from the backscattered phase and amplitude data. The primary goal of the system is the detection of weapons and the placement of the detected weapon on the body. An important additional goal is the identification of detected items, which requires a high resolution imaging technique. An experimental system has been developed at PNL which has gathered millimeter wave imagery from clothed mannequins and human beings carrying concealed weapons. This system is capable of forming images in excess of 1 meter by 2 meters at resolutions on the order of 1 cm, and is capable of scanning in less than 5 seconds. This experimental system could be enhanced to function in real time by eliminating the relatively slow mechanical scan. A sequentially switched linear array of transceiver antennas would allow real-time gathering of the imaging information, since the data would be electronically scanned in the lateral direction and electronically swept in frequency. This allows formation of a 2D image from a 1D array of transceiver antennas.

  8. Content-Based Multi-Channel Network Coding Algorithm in the Millimeter-Wave Sensor Network

    PubMed Central

    Lin, Kai; Wang, Di; Hu, Long

    2016-01-01

    With the development of wireless technology, the widespread use of 5G is already an irreversible trend, and millimeter-wave sensor networks are becoming more and more common. However, due to the high degree of complexity and bandwidth bottlenecks, the millimeter-wave sensor network still faces numerous problems. In this paper, we propose a novel content-based multi-channel network coding algorithm, which uses the functions of data fusion, multi-channel and network coding to improve the data transmission; the algorithm is referred to as content-based multi-channel network coding (CMNC). The CMNC algorithm provides a fusion-driven model based on the Dempster-Shafer (D-S) evidence theory to classify the sensor nodes into different classes according to the data content. By using the result of the classification, the CMNC algorithm also provides the channel assignment strategy and uses network coding to further improve the quality of data transmission in the millimeter-wave sensor network. Extensive simulations are carried out and compared to other methods. Our simulation results show that the proposed CMNC algorithm can effectively improve the quality of data transmission and has better performance than the compared methods. PMID:27376302

  9. Anti-reflection Coating for Cryogenic Silicon and Alumina Lenses in Millimeter-Wave Bands

    NASA Astrophysics Data System (ADS)

    Nitta, Tom; Sekiguchi, Shigeyuki; Sekimoto, Yutaro; Mitsui, Kenji; Okada, Norio; Karatsu, Kenichi; Naruse, Masato; Sekine, Masakazu; Matsuo, Hiroshi; Noguchi, Takashi; Seta, Masumichi; Nakai, Naomasa

    2014-09-01

    A dielectric lens with high refractive index is suitable for focusing cryogenic devices in millimeter-wave bands when an appropriate anti-reflection (AR) coating is applied. Two types of AR coatings for silicon and alumina were studied at the millimeter-wave (220 GHz) band: one is by direct machining of mixed epoxy for a silicon lens array, while the other is by laser machining of an antireflective subwavelength structure for a large alumina lens used in a re-imaging optics system. The millimeter-wave optical properties of silicon, alumina, aluminum nitride, and Stycast epoxies were measured with a Fourier Transform Spectrometer (FTS) at cryogenic temperatures. The measured refractive index of the AR coating with a mixture of Stycast 1266 (n = 1.68) and Stycast 2850FTJ (n = 2.2) for silicon at 30 K was 1.84. The thickness of the epoxy AR coating was precisely controlled with direct machining. Transmittance of the AR-coated silicon substrate, measured with FTS, was approximately 95 % at the center frequency of the 220 GHz band with a bandwidth of 25 % at 27 K. An antireflective subwavelength structure was designed for an alumina sample with periodic cylindrical holes. The measured 220-GHz-band transmittance was above 90 % with a bandwidth of 25 % at 25 K.

  10. Biological effects of millimeter-wave irradiation. Final report, 15 April 1984-31 March 1986

    SciTech Connect

    Gandhi, O.P.; Hill, D.W.; Furia, L.; Iskander, M.F.; Ghodgaonkar, D.

    1987-04-01

    Experiments were conducted to verify the reported high degree of sensitivity of growth rates of yeast cultures to frequency of millimeter-wave irradiation in the band 41.650 to 41.798 GHz. A new irradiation chamber was designed and built to allow simultaneous irradiation and sham irradiation of recirculating suspension of Saccharomyces cerevisiae that were maintained with a temperature difference of less than 0.01 C. No difference larger than plus or minus 4% was ever detected in the growth rates at any of the highly stabilized (within plus or minus 50 Hz) irradiation frequencies for which the effects had been reported by earlier workers. Experiments were also performed to determine the Raman spectra of cultures of Bacillus megaterium to investigate if these are dependent on the stage of their life cycle as reported by Webb et al. The results were negative. A further study to investigate the ability of millimeter waves to induce conformational changes in lipid bilayers of dipalmitoylphosphatidycholine (DPPC) liposomes below and above the transition temperature of 41/sup 0/C also gave negative results. For these experiments the conformational characteristics of the liposomes were evaluated using Raman spectra with and without millimeter-wave irradiation at 41.650 GHz.

  11. Three-Dimensional Millimeter-wave Imaging for Concealed Weapon Detection

    SciTech Connect

    Sheen, David M. ); McMakin, Douglas L. ); Hall, Thomas E. )

    2000-12-01

    Millimeter-wave imaging techniques and systems have been developed at the Pacific Northwest National Laboratory (PNNL) for the detection of concealed weapons and contraband at airports and other secure locations. These techniques were derived from microwave holography techniques which utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited to the detection of concealed weapons or other contraband carried on personnel since millimeter-waves are non-ionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, a wide-bandwidth, three-dimensional, holographic microwave imaging technique is described. Practical weapon detection systems for airport, or other high-throughput applications, require high-speed scanning on the order of 3 to 10 seconds. To achieve this goal, a prototype imaging system utilizing a 2 7-33 GHz linear sequentially switched array and a high-speed linear scanner has been developed and tested. This system is described in detail along with numerous imaging results.

  12. Content-Based Multi-Channel Network Coding Algorithm in the Millimeter-Wave Sensor Network.

    PubMed

    Lin, Kai; Wang, Di; Hu, Long

    2016-07-01

    With the development of wireless technology, the widespread use of 5G is already an irreversible trend, and millimeter-wave sensor networks are becoming more and more common. However, due to the high degree of complexity and bandwidth bottlenecks, the millimeter-wave sensor network still faces numerous problems. In this paper, we propose a novel content-based multi-channel network coding algorithm, which uses the functions of data fusion, multi-channel and network coding to improve the data transmission; the algorithm is referred to as content-based multi-channel network coding (CMNC). The CMNC algorithm provides a fusion-driven model based on the Dempster-Shafer (D-S) evidence theory to classify the sensor nodes into different classes according to the data content. By using the result of the classification, the CMNC algorithm also provides the channel assignment strategy and uses network coding to further improve the quality of data transmission in the millimeter-wave sensor network. Extensive simulations are carried out and compared to other methods. Our simulation results show that the proposed CMNC algorithm can effectively improve the quality of data transmission and has better performance than the compared methods.

  13. System-in-package LTCC platform for 3D RF to millimeter wave

    NASA Astrophysics Data System (ADS)

    Vähä-Heikkilä, T.; Lahti, M.

    2011-04-01

    This presentation shows recent trends and results in 3D Low Temperature Co-Fired Ceramics (LTCC) modules in applications from RF to millimeter waves. The system-in-package LTCC platform is a true three dimensional module technology. LTCC is a lightweight multi-layer technology having typically 6-20 ceramic layers and metallizations between. The metallization levels i.e different metal layers can be patterned and connected together with metal vias. Passive devices can also be fabricated on LTCC while active devices and other chips are connected with flip-chip, wire bonding or soldering. In addition to passives directly fabricated to LTCC, several different technologies/ chips can be hybrid integrated to the same module. LTCC platform is also well suited for the realization of antenna arrays for microwave and millimeter wave applications. Potential applications are ranging from short range communications to space and radars. VTT has designed, fabricated and characterized microwave and millimeter wave packages for Radio Frequency (RF) Micro Electro Mechanical Systems (MEMS) as well as active devices. Also, several types of system-in-package modules have been realized containing hybrid integrated CMOS and GaAs MMICs and antenna arrays.

  14. Development and Testing of a Refractory Millimeter-Wave Absorbent Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Lambot, Thomas; Myrabo, Leik; Murakami, David; Parkin, Kevin

    2014-01-01

    Central to the Millimeter-Wave Thermal Launch System (MTLS) is the millimeter-wave absorbent heat exchanger. We have developed metallic and ceramic variants, with the key challenge being the millimeter-wave absorbent coatings for each. The ceramic heat exchanger came to fruition first, demonstrating for the first time 1800 K peak surface temperatures under illumination by a 110 GHz Gaussian beam. Absorption efficiencies of up to 80 are calculated for mullite heat exchanger tubes and up to 50 are calculated for alumina tubes. These are compared with estimates based on stratified layer and finite element analyses. The problem of how to connect the 1800 K end of the ceramic tubes to a graphite outlet manifold and nozzle is solved by press fitting, or by threading the ends of the ceramic tubes and screwing them into place. The problem of how to connect the ceramic tubes to a metallic or nylon inlet pipe is solved by using soft compliant PTFE and PVC tubes that accommodate thermal deformations of the ceramic tubes during startup and operation. We show the resulting heat exchangers in static tests using argon and helium as propellants.

  15. Molten salt dynamics in glass melts using millimeter-wave emissivity measurements

    SciTech Connect

    Woskov, Paul P.; Sundaram, S K.; Daniel, Jr., William E.; Miller, Donald H.

    2004-08-01

    Non-contact millimeter-wave measurements at a frequency of 137 GHz were used to detect the thermal emission and reflectivity from the molten surface of Defense Waste Processing Facility (DWPF) black frit glass as sodium sulfate salt was added. The experiments were carried out in the EV-16 melter at Clemson Environmental Technology Laboratory (CETL) with 245 lbs. (111 kG) of glass and a total of 4.2 lbs. (1.9 kG) of added salt. The dynamics of salt layer build up were observed from the initial formation of small drops of about 5 mm diameter or less to larger pools > 28 mm cross-section that were coincident with the increase in millimeter-wave surface level fluctuations causing the salt to flow back and forth until a continuous layer was formed. The millimeter-wave emissivity at 137 GHz of DWPF black frit glass melt and molten sodium sulfate salt at 950 C was determined to be 0.64 +/-0.05 and 0.44 +/-0.05, respectively.

  16. 1,3-Propanediol millimeter wave spectrum: Conformers I and II

    NASA Astrophysics Data System (ADS)

    Smirnov, I. A.; Alekseev, E. A.; Piddyachiy, V. I.; Ilyushin, V. V.; Motiyenko, R. A.

    2013-11-01

    We present a new study of the millimeter wave spectrum of the lowest two conformers of the 1,3-propanediol (CH2OHCH2CH2OH) molecule. The new measurements involving rotational transitions with J up to 65 and Ka up to 30 for conformer I and J up to 59 and Ka up to 29 for conformer II have been carried out between 49 and 237 GHz using the Kharkov millimeter wave spectrometer. The new data were combined with previously published measurements and fitted using a model that assumes a symmetric potential energy surface with two minima between which the system tunnels. The final fit included 19 parameters for conformer I and 23 parameters for conformer II with weighted root-mean-square deviations of 0.81 and 0.73 achieved for datasets consisting of 3384 and 2947 line frequencies belonging to the ground states of conformer I and conformer II, respectively. The millimeter wave spectra of both conformers reveal a rather strong influence of the Coriolis type perturbation, which previously was not taken into account in the analysis of the 1,3-propanediol spectrum.

  17. Millimeter-Wave Wireless Power Transfer Technology for Space Applications

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Manohara, Harish; Mojarradi, Mohammad M.; Vo, Tuan A.; Mojarradi, Hadi; Bae, Sam Y.; Marzwell, Neville

    2008-01-01

    In this paper we present a new compact, scalable, and low cost technology for efficient receiving of power using RF waves at 94 GHz. This technology employs a highly innovative array of slot antennas that is integrated on substrate composed of gold (Au), silicon (Si), and silicon dioxide (SiO2) layers. The length of the slots and spacing between them are optimized for a highly efficient beam through a 3-D electromagnetic simulation process. Antenna simulation results shows a good beam profile with very low side lobe levels and better than 93% antenna efficiency.

  18. Polarizer design for millimeter-wave plasma diagnostics.

    PubMed

    Leipold, F; Salewski, M; Jacobsen, A S; Jessen, M; Korsholm, S B; Michelsen, P K; Nielsen, S K; Stejner, M

    2013-08-01

    Radiation from magnetized plasmas is in general elliptically polarized. In order to convert the elliptical polarization to linear polarization, mirrors with grooved surfaces are currently employed in our collective Thomson scattering diagnostic at ASDEX Upgrade. If these mirrors can be substituted by birefringent windows, the microwave receivers can be designed to be more compact at lower cost. Sapphire windows (a-cut) as well as grooved high density polyethylene windows can serve this purpose. The sapphire window can be designed such that the calculated transmission of the wave energy is better than 99%, and that of the high density polyethylene can be better than 97%.

  19. Polarizer design for millimeter-wave plasma diagnostics

    SciTech Connect

    Leipold, F.; Salewski, M.; Jacobsen, A. S.; Jessen, M.; Korsholm, S. B.; Michelsen, P. K.; Nielsen, S. K.; Stejner, M.

    2013-08-15

    Radiation from magnetized plasmas is in general elliptically polarized. In order to convert the elliptical polarization to linear polarization, mirrors with grooved surfaces are currently employed in our collective Thomson scattering diagnostic at ASDEX Upgrade. If these mirrors can be substituted by birefringent windows, the microwave receivers can be designed to be more compact at lower cost. Sapphire windows (a-cut) as well as grooved high density polyethylene windows can serve this purpose. The sapphire window can be designed such that the calculated transmission of the wave energy is better than 99%, and that of the high density polyethylene can be better than 97%.

  20. Millimeter-Wave Wireless Power Transfer Technology for Space Applications

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Manohara, Harish; Mojarradi, Mohammad M.; Vo, Tuan A.; Mojarradi, Hadi; Bae, Sam Y.; Marzwell, Neville

    2008-01-01

    In this paper we present a new compact, scalable, and low cost technology for efficient receiving of power using RF waves at 94 GHz. This technology employs a highly innovative array of slot antennas that is integrated on substrate composed of gold (Au), silicon (Si), and silicon dioxide (SiO2) layers. The length of the slots and spacing between them are optimized for a highly efficient beam through a 3-D electromagnetic simulation process. Antenna simulation results shows a good beam profile with very low side lobe levels and better than 93% antenna efficiency.

  1. Examination of millimeter-wave performance potential of modulation doped AlGaAs/GaAs FET structures

    NASA Astrophysics Data System (ADS)

    Das, M. B.

    1985-09-01

    This investigation involved a critical examination of the millimeter-wave performance requirements of the modulation-doped n-AlGaAs/GaAs FET structures. The results of this study revealed the need for a high aspect ration design for the gate structure of MODFET's for millimeter-wave performance. A detailed design procedure has also been developed for submicron gate-length MODFET's, determination of carrier saturation velocity, and power gain and noise figure performance of MODFET's.

  2. Experimental validation of a millimeter wave radar technique to remotely sense atmospheric pressure at the Earth's surface

    NASA Technical Reports Server (NTRS)

    Flower, D. A.; Peckham, G. E.; Bradford, W. J.

    1984-01-01

    Experiments with a millimeter wave radar operating on the NASA CV-990 aircraft which validate the technique for remotely sensing atmospheric pressure at the Earth's surface are described. Measurements show that the precise millimeter wave observations needed to deduce pressure from space with an accuracy of 1 mb are possible, that sea surface reflection properties agree with theory and that the measured variation of differential absorption with altitude corresponds to that expected from spectroscopic models.

  3. Application of Temperature-Dependent Fluorescent Dyes to the Measurement of Millimeter Wave Absorption in Water Applied to Biomedical Experiments

    PubMed Central

    Popenko, Oleksandr

    2014-01-01

    Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in small biological objects. PMID:25435859

  4. Open-path millimeter-wave spectroscopy in the 225--315 GHz range

    SciTech Connect

    Gopalsami, N.; Bakhtiari, S.; Raptis, A.C.

    1996-10-01

    This paper discusses the development of an open-path millimeter-wave (mm-wave) spectroscopy system in the 225--315 GHz atmospheric window. The new system is primarily a monostatic swept-frequency radar consisting of a mm-wave sweeper, hot-electron-bolometer or Schottky detector, and trihedral reflector. The heart of the system is a Russian backward-wave oscillator (BWO) tube that is tunable over 225--350 GHz. A mm-wave sweeper has been built with the BWO tube to sweep the entire frequency range within 1 s. The chemical plume to be detected is situated between the transmitter/receiver and the reflector. Millimeter-wave absorption spectra of chemicals in the plume are determined by measuring swept-frequency radar signals with and without the plume in the beam path. Because of power supply noise and thermal instabilities within the BWO structure over time, the BWO frequencies fluctuate between sweeps and thus cause errors in baseline subtraction. To reduce this frequency-jitter problem, a quasi-optical Fabry-Perot cavity is used in conjunction with the radar for on-line calibration of sweep traces, allowing excellent baseline subtraction and signal averaging. Initial results of the new system are given for open-path detection of chemicals.

  5. The Millimeter-Wave Rotational Spectrum of Phenylacetylene

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Kra'Snicki, Adam

    2010-06-01

    The rotational spectrum of phenylacetylene, C_6H_5-CequivC-H, has hitherto only been studied in the centimeter-wave region, at room-temperature, and in supersonic expansion. There appears to be continuing astrophysical interest in polar species closely related to benzene and we decided to extend the knowledge of the laboratory spectrum of phenylacetylene up to the submillimeter-wave region. We report extensive measurements of the room-temperature spectrum at frequencies from 90 to 340 GHz. Precise spectroscopic constants are determined for the ground state, and the two lowest excited vibrational states: v24=1 and v36=1. The two excited states belong to the out-of-plane and the in-plane C-CequivC bending modes, and are very strongly coupled by an a-axis Coriolis interaction. It was, nevertheless, possible to successfully fit the measured transitions with a minimal number of interaction constants. The present results from rotational spectroscopy are compared with previous normal mode analyses for phenylacetylene and with additional anharmonic force field calculations carried out in this work. A.P.Cox, I.C.Ewart, W.M.Stigliani, J. Chem. Soc. Farad. Trans II 71, 504-514 (1975). H.Dreizler, H.D.Rudolph, B.Hartke, J. Mol. Struct., 698, 1-24 (2004).

  6. Analysis of millimeter-wave imaging and detection

    NASA Astrophysics Data System (ADS)

    Lanigan, W.; Butler, E.; Duffy, E.; Mc Auley, I.; Young, L.; Gradziel, M.; O'Sullivan, C.; Murphy, J. A.; May, R.; Trappe, N.

    2007-02-01

    The properties of terahertz (THz) radiation potentially make it ideal for medical imaging but the difficulty of producing laboratory sources and detectors has meant that it is the last unexplored part of the electromagnetic spectrum. In this paper we report on near-field reflection and absorption measurements of biological samples at 0.1THz as a first step towards developing THz and millimetre-wave imaging schemes. Variation of the absorption and reflection of THz in these samples is investigated as a means of determining information about the sample structure. Operating at 100 GHz with standard detecting devices we illustrate preliminary results in imaging (transmission and reflection) measurements of meat samples using various optical configurations and draw conclusions on the scope of the techniques. Some encouraging provisional results are discussed as well as limitations in "intensity only" measurements due, primarily, to standing waves and a lack of dynamic range. These experiments were performed as part of a Masters thesis. A discussion on a variety of absorbing materials utilized to reduce reflected radiation from surrounding optical components is also given. In addition we report on initial trials in extracting information about an object's size by sparsely measuring points in the equivalent Fourier plane in a simple optical setup, thus avoiding the need for time consuming raster scanning. This technique has many potential applications in detecting and scanning systems. Here the background theory and preliminary results are presented.

  7. Millimeter wave detection via Autler-Townes splitting in rubidium Rydberg atoms

    SciTech Connect

    Gordon, Joshua A. Holloway, Christopher L.; Schwarzkopf, Andrew; Anderson, Dave A.; Miller, Stephanie; Thaicharoen, Nithiwadee; Raithel, Georg

    2014-07-14

    In this paper, we demonstrate the detection of millimeter waves via Autler-Townes splitting in {sup 85}Rb Rydberg atoms. This method may provide an independent, atom-based, SI-traceable method for measuring mm-wave electric fields, which addresses a gap in current calibration techniques in the mm-wave regime. The electric-field amplitude within a rubidium vapor cell in the WR-10 wave guide band is measured for frequencies of 93.71 GHz and 104.77 GHz. Relevant aspects of Autler-Townes splitting originating from a four-level electromagnetically induced transparency scheme are discussed. We measured the E-field generated by an open-ended waveguide using this technique. Experimental results are compared to a full-wave finite element simulation.

  8. Development and testing of a fast Fourier transform high dynamic-range spectral diagnostics for millimeter wave characterization

    SciTech Connect

    Thoen, D. J.; Bongers, W. A.; Westerhof, E.; Baar, M. R. de; Berg, M. A. van den; Beveren, V. van; Goede, A. P. H.; Graswinckel, M. F.; Schueller, F. C.; Oosterbeek, J. W.; Buerger, A.; Hennen, B. A.

    2009-10-15

    A fast Fourier transform (FFT) based wide range millimeter wave diagnostics for spectral characterization of scattered millimeter waves in plasmas has been successfully brought into operation. The scattered millimeter waves are heterodyne downconverted and directly digitized using a fast analog-digital converter and a compact peripheral component interconnect computer. Frequency spectra are obtained by FFT in the time domain of the intermediate frequency signal. The scattered millimeter waves are generated during high power electron cyclotron resonance heating experiments on the TEXTOR tokamak and demonstrate the performance of the diagnostics and, in particular, the usability of direct digitizing and Fourier transformation of millimeter wave signals. The diagnostics is able to acquire 4 GHz wide spectra of signals in the range of 136-140 GHz. The rate of spectra is tunable and has been tested between 200 000 spectra/s with a frequency resolution of 100 MHz and 120 spectra/s with a frequency resolution of 25 kHz. The respective dynamic ranges are 52 and 88 dB. Major benefits of the new diagnostics are a tunable time and frequency resolution due to postdetection, near-real time processing of the acquired data. This diagnostics has a wider application in astrophysics, earth observation, plasma physics, and molecular spectroscopy for the detection and analysis of millimeter wave radiation, providing high-resolution spectra at high temporal resolution and large dynamic range.

  9. Integrated horn antennas for millimeter-wave applications

    NASA Astrophysics Data System (ADS)

    Rebeiz, Gabriel M.; Katehi, Linda P. B.; Ali-Ahmad, Walid Y.; Eleftheriades, George V.; Ling, Curtis C.

    1992-02-01

    The development of integrated horn antennas since their introduction in 1987 is reviewed. The integrated horn is fabricated by suspending a dipole antenna, on a thin dielectric membrane, in a pyramidal cavity etched in silicon. Recent progress has resulted in optimized low- and high-gain designs, with single and double polarization for remote-sensing and communication applications. A full-wave analysis technique has resulted in an integrated antenna with performance comparable to that of waveguide-fed corrugated-horn antennas. The integrated horn design can be extended to large arrays, for imaging and phased-array applications, while leaving plenty of room for the RF and IF processing circuitry. Theoretical and experimental results at microwave frequencies and at 90 GHz, 240 GHz, and 802 GHz are presented.

  10. Millimeter-wave sounders/imagers for spaceborne Earth observations and reconnaissance

    NASA Astrophysics Data System (ADS)

    Kreiss, William T.; Galin, Israel

    1997-06-01

    Microwaves (MW) and Millimeter Waves (MMW) have the known benefit of penetrating the turbid Earth atmosphere under conditions where visible and infrared wave display rather limited optical depth. Radars represent conventional implementations of MMW sensor systems, while radiometers embody evolving, environmentally friendly, covert systems for civilian and military applications. This paper reviews the evolution of spaceborne passive MW and MMW sensor systems as primarily represented by Aerojet sensor products for atmospheric parameter sounding/imaging. The paper assesses current trends, and provides an outlook for the future of such sensor systems.

  11. Electronically swept millimeter-wave interferometer for spatially resolved measurement of plasma electron density.

    PubMed

    Howard, John; Oliver, David

    2006-12-01

    We report the development and initial implementation of what we believe to be a new rapid- spatial-scan millimeter-wave interferometer for plasma density measurements. The fast scan is effected by electronic frequency sweeping of a wideband (180-280 GHz) backward-wave oscillator whose output is focused onto a fixed blazed diffraction grating. The system, which augments the rotating-grating scanned multiview H-1 heliac interferometer, can sweep the plasma cross section in a period of less than 1 ms with a beam diameter in the plasma of 20 mm and phase noise of the order of 0.01 rad.

  12. Simulation of Active and Passive Millimeter-Wave (35GHz) Sensors by Time Series Analysis.

    DTIC Science & Technology

    1982-11-01

    Wave (MMW) Radiometric Data",ARBRL-TR-02338,July 1981. 3 Lon-Mu Liu,"User’s Manual for BMDQ2T(TSPACK) Time Series Analysis (Box- Jenkins)",Technical...ESTIMATED AUTOCORRELATION AND PARTIAL AUTOCORRELATION FUNCIONS OF RESIDUALS (ARTMA(2,0,(2))) MEAN - -.0000403 STANDARD DEVIATION - .0229 ACF 670...R. T.,"A Time Series and !ntervention Analysis of Millimeter-Wave (MMW) Radiometric Data", ARBRL-TR-02338, July 1981. 3. Lon-Mu Liu,"User’s Manual

  13. Quasi-Optical Techniques for Millimeter and Submillimeter-Wave Circuits.

    DTIC Science & Technology

    1981-03-25

    array , Half-wave slot , Printed lines, Patch antennas 211k Amn’q T ) e r 0 ff ne.." d ’ tr by block number) MrITh’is report summarizes research...image guide from a planar printed network in which solid state devices may be installed. The structure consists of a Yagi-Uda slot array created in the...Paul and T. ltoh, "Millimeter-wave planar slot antennas with dielectric feeds," 1981 IEEE MTT International Microwave Symposium, Los Angeles, CA, June

  14. Models of millimeter-wave emission from dust in the coma of Comet 67P

    NASA Astrophysics Data System (ADS)

    Kareta, Theodore R.; Schloerb, F. Peter

    2017-01-01

    The spacecraft Rosetta ended its mission on September 30th, 2016 after spending more than 2 years studying Comet 67P/Churyumov-Gerasimenko. The comet is constantly emitting gas and ejecting dust as it moves through the inner solar system, and understanding the properties of the gas and dust can help us better understand the comet and its origins. We present the results of a Monte Carlo simulation of dust production developed for comparison with millimeter and submillimeter data obtained by the Microwave Instrument for the Rosetta Orbiter (MIRO). The MIRO instrument measures the millimeter-wave continuum emission from the comet at two wavelengths, 0.53 mm and 1.59 mm. During the months around the August 2015 perihelion of the comet, a small emission excess was observed above the sunlit limb of the comet. The excess emission extends many beam widths off the dayside limb and is a persistent feature for months of observations. No excess is observed above the nightside limb, and given the known strong day-night asymmetry of gas production from the nucleus, we interpret the observed continuum excess on the day side to result from thermal emission from dust. A full treatment of the millimeter-wave emission from the large dust particles observed by MIRO must include many effects, including acceleration of dust particles by outflowing gas and the integration of millimeter-wave emission from a broad range of particle sizes. Our model also incorporates an accurate cometary shape model to demonstrate how dust production might vary with solar illumination over the surface. We find that the complex shape of 67P can lead to asymmetric structures in the distribution of the coma dust, with significant enhancements occurring where large areas of the nucleus have similar orientations with respect to the Sun.

  15. High power folded waveguide millimeter-wave gyro-TWT

    SciTech Connect

    Choi, J.J.; Ganguly, A.K.; Armstrong, C.M.

    1994-12-31

    Investigations on a periodic TE serpentine waveguide gyro-TWT are underway at NRL. A high power axis-encircling electron beam interacts with a fundamental TE waveguide mode when it passes through an oversized beam tunnel hole in the narrow wall of the H-plane bend rectangular serpentine waveguide. Potential advantages of the circuit configuration include: easy fabrication, fundamental forward space harmonic operation, large beam tunnel suitable for high power application, natural separation of beam and rf, and simplicity of coupling. To avoid bandwidth reduction due to closely spaced stop-bands and large gap detuning angle, a double rigid TE folded waveguide structure is proposed. To utilize the entire bandwidth, it is necessary to suppress gyro-BWO oscillation at the higher space harmonics. Linear theory predicts that oscillation takes place at {approximately} 7 cm near the stop-band frequency. Therefore, a multi-stage configuration is required to saturate the device without oscillations. An experiment is underway at NRL to verify the negative mass instability in both fast and slow wave regions in a transverse folded waveguide structure and to investigate the basic circuit stability characteristics. Design parameters of the amplifier, large signal simulations using a MAGIC code and cold-test results of the circuit components will be presented.

  16. Properties of barium strontium titanate at millimeter wave frequencies

    SciTech Connect

    Osman, Nurul; Free, Charles

    2015-04-24

    The trend towards using higher millimetre-wave frequencies for communication systems has created a need for accurate characterization of materials to be used at these frequencies. Barium Strontium Titanate (BST) is a ferroelectric material whose permittivity is known to change as a function of applied electric field and have found varieties of application in electronic and communication field. In this work, new data on the properties of BST characterize using the free space technique at frequencies between 145 GHz and 155 GHz for both thick film and bulk samples are presented. The measurement data provided useful information on effective permittivity and loss tangent for all the BST samples. Data on the material transmission, reflection properties as well as loss will also be presented. The outcome of the work shows through practical measurement, that BST has a high permittivity with moderate losses and the results also shows that BST has suitable properties to be used as RAM for high frequency application.

  17. Progress towards dual vertical slot modulator for millimeter wave photonics

    NASA Astrophysics Data System (ADS)

    Kozacik, Stephen T.; Murakowski, Maciej; Konkol, Matthew; Addya, Suman; Eng, David L. K.; Olbricht, Benjamin C.; Zablocki, Mathew J.; Sharkawy, Ahmed; Murakowski, Janusz; Shi, Shouyuan; Prather, Dennis W.

    2013-03-01

    Dual vertical slot modulators leverage the field enhancement provided by the continuity of the normal electric flux density across a boundary between two dielectrics to increase modal confinement and overlap for the propagating optical and RF waves. This effect is achieved by aligning a conventional silicon-based optical slot waveguide with a titanium dioxide RF slot. The TiO2 has an optical refractive index lower than silicon, but a significantly higher index in the RF regime. The dual slot design confines both the optical and RF modes to the same void between the silicon ribs of the optical slot waveguide. To obtain modulation of the optical signal, the void is filled with an organic electro optic material (OEOM), which offers a high optical non-linearity. The optical and RF refractive index of the OEOM is lower than silicon and can be deposited through spin processing. This design causes an extremely large mode overlap between the optical field and the RF field within the non-linear OEOM material which can result in a device with a low Vπ and a high operational bandwidth. We present work towards achieving various prototypes of the proposed device, and we discuss the fabrication challenges inherent to its design.

  18. The Chromospheric Solar Millimeter-wave Cavity Originates in the Temperature Minimum Region

    NASA Astrophysics Data System (ADS)

    De la Luz, Victor; Raulin, Jean-Pierre; Lara, Alejandro

    2013-01-01

    We present a detailed theoretical analysis of the local radio emission at the lower part of the solar atmosphere. To accomplish this, we have used a numerical code to simulate the emission and transport of high-frequency electromagnetic waves from 2 GHz up to 10 THz. As initial conditions, we used VALC, SEL05, and C7 solar chromospheric models. In this way, the generated synthetic spectra allow us to study the local emission and absorption processes with high resolution in both altitude and frequency. Associated with the temperature minimum predicted by these models, we found that the local optical depth at millimeter wavelengths remains constant, producing an optically thin layer that is surrounded by two layers of high local emission. We call this structure the Chromospheric Solar Millimeter-wave Cavity (CSMC). The temperature profile, which features temperature minimum layers and a subsequent temperature rise, produces the CSMC phenomenon. The CSMC shows the complexity of the relation between the theoretical temperature profile and the observed brightness temperature and may help us to understand the dispersion of the observed brightness temperature in the millimeter wavelength range.

  19. THE CHROMOSPHERIC SOLAR MILLIMETER-WAVE CAVITY ORIGINATES IN THE TEMPERATURE MINIMUM REGION

    SciTech Connect

    De la Luz, Victor; Raulin, Jean-Pierre; Lara, Alejandro

    2013-01-10

    We present a detailed theoretical analysis of the local radio emission at the lower part of the solar atmosphere. To accomplish this, we have used a numerical code to simulate the emission and transport of high-frequency electromagnetic waves from 2 GHz up to 10 THz. As initial conditions, we used VALC, SEL05, and C7 solar chromospheric models. In this way, the generated synthetic spectra allow us to study the local emission and absorption processes with high resolution in both altitude and frequency. Associated with the temperature minimum predicted by these models, we found that the local optical depth at millimeter wavelengths remains constant, producing an optically thin layer that is surrounded by two layers of high local emission. We call this structure the Chromospheric Solar Millimeter-wave Cavity (CSMC). The temperature profile, which features temperature minimum layers and a subsequent temperature rise, produces the CSMC phenomenon. The CSMC shows the complexity of the relation between the theoretical temperature profile and the observed brightness temperature and may help us to understand the dispersion of the observed brightness temperature in the millimeter wavelength range.

  20. Proof-of-Concept of a Millimeter-Wave Integrated Heterogeneous Network for 5G Cellular

    PubMed Central

    Okasaka, Shozo; Weiler, Richard J.; Keusgen, Wilhelm; Pudeyev, Andrey; Maltsev, Alexander; Karls, Ingolf; Sakaguchi, Kei

    2016-01-01

    The fifth-generation mobile networks (5G) will not only enhance mobile broadband services, but also enable connectivity for a massive number of Internet-of-Things devices, such as wireless sensors, meters or actuators. Thus, 5G is expected to achieve a 1000-fold or more increase in capacity over 4G. The use of the millimeter-wave (mmWave) spectrum is a key enabler to allowing 5G to achieve such enhancement in capacity. To fully utilize the mmWave spectrum, 5G is expected to adopt a heterogeneous network (HetNet) architecture, wherein mmWave small cells are overlaid onto a conventional macro-cellular network. In the mmWave-integrated HetNet, splitting of the control plane (CP) and user plane (UP) will allow continuous connectivity and increase the capacity of the mmWave small cells. mmWave communication can be used not only for access linking, but also for wireless backhaul linking, which will facilitate the installation of mmWave small cells. In this study, a proof-of-concept (PoC) was conducted to demonstrate the practicality of a prototype mmWave-integrated HetNet, using mmWave technologies for both backhaul and access. PMID:27571074

  1. Proof-of-Concept of a Millimeter-Wave Integrated Heterogeneous Network for 5G Cellular.

    PubMed

    Okasaka, Shozo; Weiler, Richard J; Keusgen, Wilhelm; Pudeyev, Andrey; Maltsev, Alexander; Karls, Ingolf; Sakaguchi, Kei

    2016-08-25

    The fifth-generation mobile networks (5G) will not only enhance mobile broadband services, but also enable connectivity for a massive number of Internet-of-Things devices, such as wireless sensors, meters or actuators. Thus, 5G is expected to achieve a 1000-fold or more increase in capacity over 4G. The use of the millimeter-wave (mmWave) spectrum is a key enabler to allowing 5G to achieve such enhancement in capacity. To fully utilize the mmWave spectrum, 5G is expected to adopt a heterogeneous network (HetNet) architecture, wherein mmWave small cells are overlaid onto a conventional macro-cellular network. In the mmWave-integrated HetNet, splitting of the control plane (CP) and user plane (UP) will allow continuous connectivity and increase the capacity of the mmWave small cells. mmWave communication can be used not only for access linking, but also for wireless backhaul linking, which will facilitate the installation of mmWave small cells. In this study, a proof-of-concept (PoC) was conducted to demonstrate the practicality of a prototype mmWave-integrated HetNet, using mmWave technologies for both backhaul and access.

  2. Photonic integrated circuit for all-optical millimeter-wave signal generation

    SciTech Connect

    Vawter, G.A.; Mar, A.; Zolper, J.; Hietala, V.

    1997-03-01

    Generation of millimeter-wave electronic signals and power is required for high-frequency communication links, RADAR, remote sensing and other applications. However, in the 30 to 300 GHz mm-wave regime, signal sources are bulky and inefficient. All-optical generation of mm-wave signals promises to improve efficiency to as much as 30 to 50 percent with output power as high as 100 mW. All of this may be achieved while taking advantage of the benefits of monolithic integration to reduce the overall size to that of a single semiconductor chip only a fraction of a square centimeter in size. This report summarizes the development of the first monolithically integrated all-optical mm-wave signal generator ever built. The design integrates a mode-locked semiconductor ring diode laser with an optical amplifier and high-speed photodetector into a single optical integrated circuit. Frequency generation is demonstrated at 30, 60 and 90 Ghz.

  3. Planar Superconducting Millimeter-Wave/Terahertz Channelizing Filter

    NASA Technical Reports Server (NTRS)

    Ehsan, Negar; U-yen, Kongpop; Brown, Ari; Hsieh, Wen-Ting; Wollack, Edward; Moseley, Samuel

    2013-01-01

    This innovation is a compact, superconducting, channelizing bandpass filter on a single-crystal (0.45 m thick) silicon substrate, which operates from 300 to 600 GHz. This device consists of four channels with center frequencies of 310, 380, 460, and 550 GHz, with approximately 50-GHz bandwidth per channel. The filter concept is inspired by the mammalian cochlea, which is a channelizing filter that covers three decades of bandwidth and 3,000 channels in a very small physical space. By using a simplified physical cochlear model, and its electrical analog of a channelizing filter covering multiple octaves bandwidth, a large number of output channels with high inter-channel isolation and high-order upper stopband response can be designed. A channelizing filter is a critical component used in spectrometer instruments that measure the intensity of light at various frequencies. This embodiment was designed for MicroSpec in order to increase the resolution of the instrument (with four channels, the resolution will be increased by a factor of four). MicroSpec is a revolutionary wafer-scale spectrometer that is intended for the SPICA (Space Infrared Telescope for Cosmology and Astrophysics) Mission. In addition to being a vital component of MicroSpec, the channelizing filter itself is a low-resolution spectrometer when integrated with only an antenna at its input, and a detector at each channel s output. During the design process for this filter, the available characteristic impedances, possible lumped element ranges, and fabrication tolerances were identified for design on a very thin silicon substrate. Iterations between full-wave and lumped-element circuit simulations were performed. Each channel s circuit was designed based on the availability of characteristic impedances and lumped element ranges. This design was based on a tabular type bandpass filter with no spurious harmonic response. Extensive electromagnetic modeling for each channel was performed. Four channels

  4. Planar millimeter wave radar frontend for automotive applications

    NASA Astrophysics Data System (ADS)

    Grubert, J.; Heyen, J.; Metz, C.; Stange, L. C.; Jacob, A. F.

    2003-05-01

    A fully integrated planar sensor for 77 GHz automotive applications is presented. The frontend consists of a transceiver multichip module and an electronically steerable microstrip patch array. The antenna feed network is based on a modified Rotman-lens and connected to the array in a multilayer approach offering higher integration. Furthermore, the frontend comprises a phase lock loop to allow proper frequency-modulated continuous wave (FMCW) radar operation. The latest experimental results verify the functionality of this advanced frontend design featuring automatic cruise control, precrash sensing and cut-in detection. These promising radar measurements give reason to a detailed theoretical investigation of system performance. Employing commercially available MMIC various circuit topologies are compared based on signal-tonoise considerations. Different scenarios for both sequential and parallel lobing hint to more advanced sensor designs and better performance. These improvements strongly depend on the availability of suitable MMIC and reliable packaging technologies. Within our present approach possible future MMIC developments are already considered and, thus, can be easily adapted by the flexible frontend design. Es wird ein integrierter planarer Sensor für 77 GHz Radaranwendungen vorgestellt. Das Frontend besteht aus einem Sende- und Empfangs-Multi-Chip-Modul und einer elektronisch schwenkbaren Antenne. Das Speisenetzwerk der Antenne basiert auf einer modifizierten Rotman- Linse. Für eine kompakte Bauweise sind Antenne und Speisenetzwerk mehrlagig integriert. Weiterhin umfasst das Frontend eine Phasenregelschleife für eine präzise Steuerung des frequenzmodulierten Dauerstrichradars. Die aktuellen Messergebnisse bestätigen die Funktionalit¨at dieses neuartigen Frontend-Designs, das automatische Geschwindigkeitsregelung, Kollisionswarnung sowie Nahbereichsüberwachung ermöglicht. Die Qualität der Messergebnisse hat weiterf

  5. Millimeter and submillimeter wave spectroscopy of higher energy conformers of 1,2-propanediol

    NASA Astrophysics Data System (ADS)

    Zakharenko, O.; Bossa, J.-B.; Lewen, F.; Schlemmer, S.; Müller, H. S. P.

    2017-03-01

    We have performed a study of the millimeter/submillimeter wave spectrum of four higher energy conformers of 1,2-propanediol. The present analysis of rotational transitions carried out in the frequency range 38-400 GHz represents a significant extension of previous microwave work. The new data were combined with previously-measured microwave transitions and fitted using a Watson's S-reduced Hamiltonian. The final fits were within experimental accuracy, and included spectroscopic parameters up to sixth order of angular momentum, for the ground states of the four higher energy conformers following previously studied ones: g‧Ga, gG‧g‧, aGg‧ and g‧Gg. The present analysis provides reliable frequency predictions for astrophysical detection of 1,2-propanediol by radio telescope arrays at millimeter wavelengths.

  6. Physics of propagation in left-handed guided wave structures at microwave and millimeter-wave frequencies.

    PubMed

    Krowne, Clifford M

    2004-02-06

    A microstrip configuration is loaded with a left-handed medium substrate and studied regarding its dispersion diagrams over the microwave and millimeter-wave frequency bands for a number of different modal solutions. Ab initio calculations are accomplished self-consistently with a computer code using a full-wave integral equation numerical method based upon a Green's function employing appropriate boundary conditions. Bands of both propagating and evanescent behavior are discovered in some of the modes. Electromagnetic field plots in the cross-sectional dimension are made. New electric field line and magnetic circulation patterns are discovered.

  7. Reflection imaging in the millimeter-wave range using a video-rate terahertz camera

    NASA Astrophysics Data System (ADS)

    Marchese, Linda E.; Terroux, Marc; Doucet, Michel; Blanchard, Nathalie; Pancrati, Ovidiu; Dufour, Denis; Bergeron, Alain

    2016-05-01

    The ability of millimeter waves (1-10 mm, or 30-300 GHz) to penetrate through dense materials, such as leather, wool, wood and gyprock, and to also transmit over long distances due to low atmospheric absorption, makes them ideal for numerous applications, such as body scanning, building inspection and seeing in degraded visual environments. Current drawbacks of millimeter wave imaging systems are they use single detector or linear arrays that require scanning or the two dimensional arrays are bulky, often consisting of rather large antenna-couple focal plane arrays (FPAs). Previous work from INO has demonstrated the capability of its compact lightweight camera, based on a 384 x 288 microbolometer pixel FPA with custom optics for active video-rate imaging at wavelengths of 118 μm (2.54 THz), 432 μm (0.69 THz), 663 μm (0.45 THz), and 750 μm (0.4 THz). Most of the work focused on transmission imaging, as a first step, but some preliminary demonstrations of reflection imaging at these were also reported. In addition, previous work also showed that the broadband FPA remains sensitive to wavelengths at least up to 3.2 mm (94 GHz). The work presented here demonstrates the ability of the INO terahertz camera for reflection imaging at millimeter wavelengths. Snapshots taken at video rates of objects show the excellent quality of the images. In addition, a description of the imaging system that includes the terahertz camera and different millimeter sources is provided.

  8. Diagnosis and Treatment of Neurological Disorders by Millimeter-Wave Stimulation

    NASA Technical Reports Server (NTRS)

    Siegel, Peter H.; Pikov, Victor

    2011-01-01

    Increasingly, millimeter waves are being employed for telecomm, radar, and imaging applications. To date in the U.S, however, very few investigations on the impact of this radiation on biological systems at the cellular level have been undertaken. In the beginning, to examine the impact of millimeter waves on cellular processes, researchers discovered that cell membrane depolarization may be triggered by low levels of integrated power at these high frequencies. Such a situation could be used to advantage in the direct stimulation of neuronal cells for applications in neuroprosthetics and diagnosing or treating neurological disorders. An experimental system was set up to directly monitor cell response on exposure to continuous-wave, fixed-frequency, millimeter-wave radiation at low and modest power levels (0.1 to 100 safe exposure standards) between 50 and 100 GHz. Two immortalized cell lines derived from lung and neuronal tissue were transfected with green fluorescent protein (GFP) that locates on the inside of the cell membrane lipid bi-layer. Oxonol dye was added to the cell medium. When membrane depolarization occurs, the oxonal bound to the outer wall of the lipid bi-layer can penetrate close to the inner wall where the GFP resides. Under fluorescent excitation (488 nm), the normally green GFP (520 nm) optical signal quenches and gives rise to a red output when the oxonol comes close enough to the GFP to excite a fluorescence resonance energy transfer (FRET) with an output at 620 nm. The presence of a strong FRET signature upon exposures of 30 seconds to 2 minutes at 5-10 milliwatts per square centimeter RF power at 50 GHz, followed by a return to the normal 520-nm GFP signal after a few minutes indicating repolarization of the membrane, indicates that low levels of RF energy may be able to trigger non-destructive membrane depolarization without direct cell contact. Such a mechanism could be used to stimulate neuronal cells in the cortex without the need for

  9. Characterization and Applications of Micro- and Nano- Ferrites at Microwave and Millimeter Waves

    NASA Astrophysics Data System (ADS)

    Chao, Liu

    Ferrite materials are one of the most widely used magnetic materials in microwave and millimeter wave applications such as radar, wireless communication. They provide unique properties for microwave and millimeter wave devices especially non-reciprocal devices. Some ferrite materials with strong magnetocrystalline anisotropy fields can extend these applications to tens of GHz range while reducing the size, weight and cost. This thesis focuses on characterization of such ferrite materials as micro- and nano-powder and the fabrication of the devices. The ferrite materials with strong magnetocrystalline anisotropy field are metal/non-metal substituted iron oxides oriented in low crystal symmetry. The ferrite materials characterized in this thesis include M-type hexagonal ferrites such as barium ferrite (BaFe12O19), strontium ferrite (SrFe12O19), epsilon phase iron oxide (epsilon-Fe 2O3), substituted epsilon phase iron oxide (epsilon-Ga xFe2-xO3, epsilon-AlxFe2-xO 3). These ferrites exhibit great anisotropic magnetic fields. A transmission-reflection based in-waveguide technique that employs a vector network analyzer was used to determine the scattering parameters for each sample in the microwave bands (8.2--40 GHz). From the S-parameters, complex dielectric permittivity and complex magnetic permeability are evaluated by an improved algorithm. The millimeter wave measurement is based on a free space quasi-optical spectrometer. Initially precise transmittance spectra over a broad millimeter wave frequency range from 40 GHz to 120 GHz are acquired. Later the transmittance spectra are converted into complex permittivity and permeability spectra. These ferrite powder materials are further characterized by x-ray diffraction (XRD) to understand the crystalline structure relating to the strength and the shift of the ferromagnetic resonance affected by the particle size. A Y-junction circulator working in the 60 GHz frequency band is designed based on characterized M

  10. Module integration and amplifier design optimization for optically enabled passive millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Wright, Andrew A.; Martin, Richard D.; Schuetz, Christopher A.; Shi, Shouyuan; Zhang, Yifei; Yao, Peng; Shreve, Kevin P.; Dillon, Thomas E.; Mackrides, Daniel G.; Harrity, Charles E.; Prather, Dennis W.

    2016-05-01

    This paper will discuss the development of a millimeter-wave (mm-wave) receiver module used in a sparse array passive imaging system. Using liquid crystal polymer (LCP) technology and low power InP low noise amplifiers (LNA), enables the integration of the digital circuitry along with the RF components onto a single substrate significantly improves the size, weight, power, and cost (SWaP-C) of the mm-wave receiver module compared to previous iterations of the module. Also comparing with previous generation modules, the operating frequency has been pushed from 77 GHz to 95 GHz in order to improve the resolution of the captured image from the sparse array imaging system.

  11. Modeling of Millimeter-Wave Modulation Characteristics of Semiconductor Lasers under Strong Optical Feedback

    PubMed Central

    Bakry, Ahmed

    2014-01-01

    This paper presents modeling and simulation on the characteristics of semiconductor laser modulated within a strong optical feedback (OFB-)induced photon-photon resonance over a passband of millimeter (mm) frequencies. Continuous wave (CW) operation of the laser under strong OFB is required to achieve the photon-photon resonance in the mm-wave band. The simulated time-domain characteristics of modulation include the waveforms of the intensity and frequency chirp as well as the associated distortions of the modulated mm-wave signal. The frequency domain characteristics include the intensity modulation (IM) and frequency modulation (FM) responses in addition to the associated relative intensity noise (RIN). The signal characteristics under modulations with both single and two mm-frequencies are considered. The harmonic distortion and the third order intermodulation distortion (IMD3) are examined and the spurious free dynamic range (SFDR) is calculated. PMID:25383381

  12. High power water load for microwave and millimeter-wave radio frequency sources

    DOEpatents

    Ives, R. Lawrence; Mizuhara, Yosuke M.; Schumacher, Richard V.; Pendleton, Rand P.

    1999-01-01

    A high power water load for microwave and millimeter wave radio frequency sources has a front wall including an input port for the application of RF power, a cylindrical dissipation cavity lined with a dissipating material having a thickness which varies with depth, and a rear wall including a rotating reflector for the reflection of wave energy inside the cylindrical cavity. The dissipation cavity includes a water jacket for removal of heat generated by the absorptive material coating the dissipation cavity, and this absorptive material has a thickness which is greater near the front wall than near the rear wall. Waves entering the cavity reflect from the rotating reflector, impinging and reflecting multiple times on the absorptive coating of the dissipation cavity, dissipating equal amounts of power on each internal reflection.

  13. Modeling of millimeter-wave modulation characteristics of semiconductor lasers under strong optical feedback.

    PubMed

    Bakry, Ahmed

    2014-01-01

    This paper presents modeling and simulation on the characteristics of semiconductor laser modulated within a strong optical feedback (OFB-)induced photon-photon resonance over a passband of millimeter (mm) frequencies. Continuous wave (CW) operation of the laser under strong OFB is required to achieve the photon-photon resonance in the mm-wave band. The simulated time-domain characteristics of modulation include the waveforms of the intensity and frequency chirp as well as the associated distortions of the modulated mm-wave signal. The frequency domain characteristics include the intensity modulation (IM) and frequency modulation (FM) responses in addition to the associated relative intensity noise (RIN). The signal characteristics under modulations with both single and two mm-frequencies are considered. The harmonic distortion and the third order intermodulation distortion (IMD3) are examined and the spurious free dynamic range (SFDR) is calculated.

  14. Multi-Band Multi-Tone Tunable Millimeter-Wave Frequency Synthesizer For Satellite Beacon Transmitter

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Wintucky, Edwin G.

    2016-01-01

    This paper presents the design and test results of a multi-band multi-tone tunable millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a satellite beacon transmitter for radio wave propagation studies at K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). In addition, the architecture for a compact beacon transmitter, which includes the multi-tone synthesizer, polarizer, horn antenna, and power/control electronics, has been investigated for a notional space-to-ground radio wave propagation experiment payload on a small satellite. The above studies would enable the design of robust high throughput multi-Gbps data rate future space-to-ground satellite communication links.

  15. Millimeter Wave Synthetic Aperture Imaging System with a Unique Rotary Scanning System

    NASA Technical Reports Server (NTRS)

    Ghasr, M. T.; Pommerenke, D.; Case, J. T.; McClanahan, A. D.; Afaki-Beni, A.; Abou-Khousa, M.; Guinn, K.; DePaulis, F.; Kharkovsky, S.; Zoughi, R.

    2008-01-01

    In recent years, millimeter wave imaging techniques, using synthetic aperture focusing and holographical approaches, have shown tremendous potential for nondestructive testing applications, involving materials and structures used in space vehicles, including the space shuttle external fuel tank spray on foam insulation and its acreage heat tiles. The ability of signals at millimeter wave frequencies (30 - 300 GHz) to easily penetrate inside of low loss dielectric materials, their relatively small wavelengths, and the possibility of detecting coherent (magnitude and phase) reflections make them suitable for high resolution synthetic aperture focused imaging the interior of such materials and structures. To accommodate imaging requirements, commonly a scanning system is employed that provides for a raster scan of the desired structure. However, most such scanners, although simple in design and construction, are inherently slow primarily due to the need to stop and start at the beginning and end of each scan line. To this end, a millimeter wave synthetic aperture focusing system including a custom-designed transceiver operating at 35 - 45 GHz (Q-band) and unique and complex rotary scanner was designed and developed. The rotary scanner is capable of scanning an area with approximately 80 cm in diameter in less than 10 minutes at step sizes of 3 mm and smaller. The transceiver is capable of producing accurate magnitude and phase of reflected signal from the structure under test. Finally, a synthetic aperture focusing algorithm was developed that translates this rotary-obtained magnitude and phase into a synthetic aperture focusing image of inspected structures. This paper presents the design of the transceiver and the rotary scanning system along with showing several images obtained with this system from various complicated structures.

  16. Millimeter wave ferromagnetic resonance in gallium-substituted ε-iron oxide

    SciTech Connect

    Chao, Liu Afsar, Mohammed N.; Ohkoshi, Shin-ichi

    2014-05-07

    In millimeter wave frequency range, hexagonal ferrites with high uniaxial anisotropic magnetic fields are used as absorbers. These ferrites include M-type barium ferrite (BaFe{sub 12}O{sub 19}) and strontium ferrite (SrFe{sub 12}O{sub 19}), which have natural ferromagnetic resonant frequency range from 40 GHz to 60 GHz. However, the higher frequency range lacks suitable materials that support the higher frequency ferromagnetic resonance. A new series of gallium-substituted ε-iron oxides (ε-Ga{sub x}Fe{sub 2−x}O{sub 3}) are synthesized which have ferromagnetic resonant frequencies appearing over the frequency range 30 GHz–150 GHz. The ε-Ga{sub x}Fe{sub 2−x}O{sub 3} is synthesized by the combination of reverse micelle and sol-gel techniques or the sol-gel method only. The particle sizes are observed to be smaller than 100 nm. In this paper, the free space magneto-optical approach has been employed to study these newly developed ε-Ga{sub x}Fe{sub 2−x}O{sub 3} particles in millimeter waves. This technique enables to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the millimeter wave frequency range from a single set of direct measurements. The transmittance and absorbance spectra of ε-Ga{sub x}Fe{sub 2−x}O{sub 3} are shown in this paper. Strong ferromagnetic resonances at different frequencies determined by the x parameter are found.

  17. Determining bonding quality in polymer composites with a millimeter wave sensor

    SciTech Connect

    Bakhtiari, S.; Gopalsami, N.; Raptis, A.C.

    1996-12-01

    Microwave nondestructive testing (NDT) techniques offer alternative solutions to other conventional NDT methods. Microwave/millimeter wave (determined roughly to cover 0.3 to 300 GHz) techniques are particularly useful for examination of dielectric composite materials that their low dielectric losses provide good depth of penetration of electromagnetic radiation in this band. Limitations associated with conventional NDT techniques such as high frequency ultrasonic testing (UT), namely, large variations in elastic properties of low density composite materials cause interpretation of complex UT signals difficult. Further, criticality of coupling of transducer to the sample surface limits the use of such techniques for on-line applications. High frequency microwave (millimeter waves, 30--300 GHz) systems compared to their low frequency counterparts offer higher resolution and sensitivity to variations in dielectric properties of low-loss composites. Further, higher frequencies render utilization of more compact systems which are often important for practical applications. A millimeter wave sensor is described in this work which can be utilized for non-contact NDT of a wide range of thin-sheet dielectric composite materials either as a laboratory-based instrument or for on-line quality control applications. Experimental results are presented on noncontact measurement of bonding quality in polyethylene/carbon composite samples. The w-band monostatic sensor operates based on measurement of the reflection properties of the material under test, which are then used to determine the volumetric uniformity of the joint area. Preliminary experimental results indicate the potential for the use of this sensor in fabrication process control of low-loss dielectric composite materials.

  18. Speckle in Active Millimeter-Wave and Terahertz Imaging and Spectroscopy

    SciTech Connect

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2007-04-01

    Wideband millimeter-wave imaging techniques and systems have been developed at PNNL for concealed weapon detection and other applications. These techniques evolved from single-frequency millimeter-wave holographic imaging methods to wideband three-dimensional planar and cylindrical techniques and systems. The single-frequency holographic method was derived from optical and ultrasonic holography techniques. Speckle is highly significant in this case, and is caused by constructive and destructive interference from multiple scattering locations or depths within a single resolution cell. The wideband three-dimensional techniques developed at PNNL significantly reduce the speckle effect through the use of high depth resolution obtained from the wide bandwidth of the illumination. For these techniques, speckle can still be significant in some cases and affect image quality. In this paper, we explore the situations in which speckle occurs and it's relationship to lateral and depth resolution. This will be accomplished through numerical simulation and demonstrated in actual imaging results. Speckle may also play a significant role in altering reflection spectra in wideband terahertz spectra. Reflection from rough surfaces will generate speckle, which will result in significant variation in the reflection spectrum as measured over very wide bandwidths. This effect may make if difficult to interpret spectral absorption features from general reflectance data. In this paper, physical optics numerical simulation techniques will be used to model the reflection from arbitrary random surfaces and explore the effect of the surface on the reflection spectra and reconstructed image. Laboratory imaging and numerical modeling results in the millimeter-wave through the terahertz frequency ranges are presented.

  19. A high-sensitivity 135 GHz millimeter-wave imager by compact split-ring-resonator in 65-nm CMOS

    NASA Astrophysics Data System (ADS)

    Li, Nan; Yu, Hao; Yang, Chang; Shang, Yang; Li, Xiuping; Liu, Xiong

    2015-11-01

    A high-sensitivity 135 GHz millimeter-wave imager is demonstrated in 65 nm CMOS by on-chip metamaterial resonator: a differential transmission-line (T-line) loaded with split-ring-resonator (DTL-SRR). Due to sharp stop-band introduced by the metamaterial load, high-Q oscillatory amplification can be achieved with high sensitivity when utilizing DTL-SRR as quench-controlled oscillator to provide regenerative detection. The developed 135 GHz mm-wave imager pixel has a compact core chip area of 0.0085 mm2 with measured power consumption of 6.2 mW, sensitivity of -76.8 dBm, noise figure of 9.7 dB, and noise equivalent power of 0.9 fW/√{HZ } Hz. Millimeter-wave images has been demonstrated with millimeter-wave imager integrated with antenna array.

  20. Higher energy states in the CO dimer: millimeter-wave spectra and rovibrational calculations.

    PubMed

    Surin, Leonid A; Fourzikov, Dmitri N; Giesen, Thomas F; Schlemmer, Stephan; Winnewisser, Gisbert; Panfilov, Victor A; Dumesh, Boris S; Vissers, Gé W M; van der Avoird, Ad

    2007-12-13

    New extensive millimeter-wave measurements of the 12C16O dimer have been made, and more than 300 new spectral transitions have been observed in the frequency range 81-135 GHz. A joint analysis of these and previous millimeter-wave data yielded the precise location of 33 new energy levels of A+ symmetry and 20 levels of A- symmetry. These energy levels are located at 8-18 cm(-1) above the zero-point level. Some of them belong to already known stacks, and others make up 9 new stacks of the dimer. Newly determined stacks have K=0, 1, and, for the first time, 2, where K is the projection of the total angular momentum on the intermolecular axis. The energy levels from accompanying rovibrational calculations with the use of a recently developed hybrid CCSD(T)/DFT-SAPT potential are in very good agreement with experiment. Analysis of the calculated wave functions revealed that two new stacks of A+ symmetry with K=2 correspond to overall rotation of the dimer while the other newly observed stacks belong to the geared bend overtone modes. The ground vibrational states of the two "isomers" found are more or less localized at the two minima in the potential surface, whereas all the geared bend excited states show a considerable amount of delocalization.

  1. Millimeter-wave phase resonances in compound reflection gratings with subwavelength grooves.

    PubMed

    Beruete, Miguel; Navarro-Cía, Miguel; Skigin, Diana C; Sorolla, Mario

    2010-11-08

    Experimental evidence of phase resonances in a dual-period reflection structure comprising three subwavelength grooves in each period is provided in the millimeter-wave regime. We have analyzed and measured the response of these structures and show that phase resonances are characterized by a minimum in the reflected response, as predicted by numerical calculations. It is also shown that under oblique incidence these structures exhibit additional phase resonances not present for normal illumination because of the potentially permitted odd field distribution. A satisfactory agreement between the experimental and numerical reflectance curves is obtained. These results confirm the recent theoretical predictions of phase resonances in reflection gratings in the millimeter-wave regime, and encourage research in this subject due to the multiple potential applications, such as frequency selective surfaces, backscattering reduction and complex-surface-wave-based sensing. In addition, it is underlined here that the response becomes much more complex than the mere infinite analysis when one considers finite periodic structures as in the real experiment.

  2. Millimeter- and submillimeter-wave nanoscience : LDRD project 122359 final report.

    SciTech Connect

    Lee, Mark

    2008-09-01

    LDRD Project 122359 was a nine-month, late-start effort that pursued initial experiments studying the fundamental electrodynamic response properties of various nanomaterials from millimeter-wave (above roughly 30 GHz) up to submillimeter-wave (above roughly 0.1 THz) frequencies. The nine months of this project's duration produced two main empirical findings. First, Fourier transform reflectance spectroscopy on SrTiO{sub 3} nanocrystals from 0.2 to 10 THz frequency showed signatures of two optical phonons that correspond to known optical modes in bulk crystal SrTiO{sub 3}. However, quantitative differences between the nanoparticle and bulk spectra suggest that one or both of these phonons may shift frequency and weaken in nanoparticles relative to bulk crystal. Second, heavily doped n-type GaAs nanowires were synthesized for the purpose of creating high frequency diodes to study non-linear frequency conversion properties of compound semiconductor nanowires. It was found that incorporation of a heavy concentration of dopants interferes with the growth of these nanowires. While DC measurements showed reasonable diode-like current-voltage properties, the current state-of-the-art material properties of these nanowires are still unsuitable for millimeter-wave testing and applications.

  3. Telecommunication service markets through the year 2000 in relation to millimeter wave satellite systems

    NASA Technical Reports Server (NTRS)

    Stevenson, S. M.

    1979-01-01

    NASA is currently conducting a series of millimeter wave satellite system market studies to develop 30/20 GHz satellite system concepts that have commercial potential. Four contractual efforts were undertaken: two parallel and independent system studies and two parallel and independent market studies. The marketing efforts are focused on forecasting the total domestic demand for long haul telecommunications services for the 1980-2000 period. Work completed to date and reported in this paper include projections of: geographical distribution of traffic; traffic volume as a function of urban area size; and user identification and forecasted demand.

  4. Millimeter-wave spectroscopy of hydantoin, a possible precursor of glycine

    NASA Astrophysics Data System (ADS)

    Ozeki, Hiroyuki; Miyahara, Rio; Ihara, Hiroto; Todaka, Satoshi; Kobayashi, Kaori; Ohishi, Masatoshi

    2017-04-01

    Context. Hydantoin (Imidazolidine-2, 4-dione, C3H4N2O2) is a five-membered heterocyclic compound that is known to arise from prebiotic molecules such as glycolic acid and urea, and to give the simplest amino acid, glycine, by hydrolysis under acidic condition. The gas chromatography combined with the mass spectrometry of carbonaceous chondrites lead to the detection of this molecule as well as several kinds of amino acids. Aims: The lack of spectroscopic information, especially on the rotational constants, has prevented us from conducting a search for hydantoin in interstellar space. If a rotational temperature of 100 K is assumed as the kinetic temperature of a star-forming region, the spectral intensity is expected to be at its maximum in the millimeter-wave region. Laboratory spectroscopy of hydantoin in the millimeter-wave region is the most important in providing accurate rest frequencies to be used for astronomical research. Methods: Pure rotational spectra of hydantoin were observed in the millimeter-wave region using the frequency modulated microwave spectrometer at Toho University. Solid hydantoin was heated to around 150 °C to provide appropriate vapor pressure. Quantum chemical calculations suggest that the permanent dipole moment of this molecule lies almost along the b-molecular axis, so that spectral search for b-type R-branch transition has been conducted. Results: Rotational and centrifugal distortion constants up to the fourth order for the ground vibrational state of hydantoin were accurately determined by measuring 161 b-type transitions in the frequency range between 90 and 370 GHz. In addition, we succeeded in assigning 230 satellite lines, which were attributed to the two vibrationally excited states. The spectral intensity ratio of these lines indicates that these states correspond to the low-lying (approximately 150 cm-1 above the ground state) vibrational modes. Conclusions: The frequency catalog of hydantoin in the millimeter-wave range

  5. An Airborne Conical Scanning Millimeter-Wave Imaging Radiometer (CoSMIR)

    NASA Technical Reports Server (NTRS)

    Piepmeier, J.; Racette, P.; Wang, J.; Crites, A.; Doiron, T.; Engler, C.; Lecha, J.; Powers, M.; Simon, E.; Triesky, M.; hide

    2001-01-01

    An airborne Conical Scanning Millimeter-wave Imaging Radiometer (CoSMIR) for high-altitude observations from the NASA Research Aircraft (ER-2) is discussed. The primary application of the CoSMIR is water vapor profile remote sensing. Four radiometers operating at 50 (three channels), 92, 150, and 183 (three channels) GHz provide spectral coverage identical to nine of the Special Sensor Microwave Imager/Sounder (SSMIS) high-frequency channels. Constant polarization-basis conical and cross-track scanning capabilities are achieved using an elevation-under-azimuth two-axis gimbals.

  6. Characterization of delamination and disbonding in stratified dielectric composites by millimeter wave imaging

    SciTech Connect

    Bakhtiari, S.; Gopalsami, N.; Raptis, A.C.

    1995-04-01

    Electromagnetic radiation at microwave frequencies has been in use for nondestructive evaluation (NDE) of various low-loss and generally lossy dielectric materials. A monostatic backscatter millimeter wave imaging system was utilized for non-destructive characterization of defects in low-loss composites of Kevlar/epoxy. Defects consisting of subsurface delamination and disbonding defects were successfully detected and characterized. Images are constructed by measuring the relative amplitude and phase of the reflected radiation. The results clearly indicate the potential of such high-frequency systems for nondestructive characterization of small defects in low-loss dielectric composite materials.

  7. Design and testing of an active 190-GHz millimeter-wave imager

    NASA Astrophysics Data System (ADS)

    Timms, Greg P.; Brothers, Michael L.; Bunton, John D.; Archer, John W.; Rosolen, Grahame C.; Li, Yue; Hellicar, Andrew D.; Tello, Juan Y.; Hay, Stuart G.

    2010-10-01

    The design and testing of an active 190-GHz imaging system is presented. The system features two beam-scanning antennas, one of which transmits a vertical fan beam, and the other which receives a horizontal fan beam. By correlating the transmitted and received signals, an output is obtained that is proportional to the millimeter-wave reflectivity at the intersection of the two fan beams. Beam scanning is obtained by rotating a small subreflector within each antenna, allowing rapid scanning. The system has an angular resolution of 0.3 deg, a field of view of 14×14 deg, and operates at a standoff distance of 5 m.

  8. Millimeter-wave imaging with frequency scanning antenna and optical arrayed waveguide gratings

    NASA Astrophysics Data System (ADS)

    He, Yuntao; Yu, Guoxin; Fu, Xinyu; Jiang, Yuesong

    2012-12-01

    The principle of a novel passive millimeter-wave (MMW) imaging method using frequency scanning antenna (FSA) and arrayed waveguide grating (AWG) is analyzed theoretically. The imaging processes are divided to three stages and discussed respectively. Then the FSA with 33~ 43GHz frequency scanning range is designed carefully with a field of view of +/-25°for the MMW imaging system. An AWG of 1×24 is then simply designed with a channel spacing of 0.5GHz. The designing and simulating demonstrated the feasibility to build such an imaging system which is progressing.

  9. The use of two modes of oscillator operation in millimeter-wave interferometry

    NASA Astrophysics Data System (ADS)

    Skibenko, A. I.; Fomin, I. P.; Skubko, V. A.

    1980-11-01

    An investigation of the electronic tuning characteristics of diffraction-radiation oscillators for use in millimeter-wave interferometers is presented. Two modes of oscillator operation were discovered: a mode of large electronic tuning steepness and a mode of small steepness. It is shown that different phase shifts can be obtained in the same interferometer circuit at different modulation voltages. An interferometer based on this phase-shift effect was constructed; a maximum phase shift of 30pi was recorded at a wavelength of 6 mm.

  10. Review of data analysis procedures for the ATS-6 millimeter wave experiment

    NASA Technical Reports Server (NTRS)

    Meneghini, R.

    1975-01-01

    Predictions of satellite downlink attenuation through the use of ground based measurements form a substantial part of the ATS-6 millimeter wave experiment (MWE). At the downlink frequencies (20 and 30 GHz), the major causes of attenuation are the density and the size distribution of rain drops along the propagation path. Ground station data, which include radar and rain gauge records, measure quantities related to the meteorological parameters of interest and thereby provide a prediction of downlink attenuation with which the measured attenuation can be compared. The calibration and data analysis procedures used in the MWE are reviewed with the object of improving the accuracy of such ground based predictions.

  11. Millimeter wave transmission spectroscopy of gated two-dimensional hole systems

    NASA Astrophysics Data System (ADS)

    Stone, K.; Du, R. R.; Manfra, M. J.; Pfeiffer, L. N.; West, K. W.

    2012-05-01

    We developed a differential transmission to study cyclotron resonance of GaAs/AlxGa1-xAs two-dimensional hole samples. The technique utilizes a modulated AuPd gate isolated by a Si3 N4 dielectric from the sample, which is irradiated opposite the gate by millimeter waves ranging from 2 to 40 GHz. This technique effectively removes the background signal and yields a hole effective mass of 0.41me with a cyclotron scattering time of ˜20 ps, consistent with the previous results using different techniques.

  12. High-performance packaging for monolithic microwave and millimeter-wave integrated circuits

    NASA Technical Reports Server (NTRS)

    Shalkhauser, K. A.; Li, K.; Shih, Y. C.

    1992-01-01

    Packaging schemes are developed that provide low-loss, hermetic enclosure for enhanced monolithic microwave and millimeter-wave integrated circuits. These package schemes are based on a fused quartz substrate material offering improved RF performance through 44 GHz. The small size and weight of the packages make them useful for a number of applications, including phased array antenna systems. As part of the packaging effort, a test fixture was developed to interface the single chip packages to conventional laboratory instrumentation for characterization of the packaged devices.

  13. Ka-band Dielectric Waveguide Antenna Array for Millimeter Wave Active Imaging System

    NASA Astrophysics Data System (ADS)

    Fang, Weihai; Fei, Peng; Nian, Feng; Yang, Yujie; Feng, Keming

    2014-11-01

    Ka-band compact dielectric waveguide antenna array for active imaging system is given. Antenna array with WR28 metal waveguide direct feeding is specially designed with small size, high gain, good radiation pattern, easy realization, low insertion loss and low mutual coupling. One practical antenna array for 3-D active imaging system is shown with theoretic analysis and experimental results. The mutual coupling of transmitting and receiving units is less than -30dB, the gain from 26.5GHz to 40GHz is (12-16) dB. The results in this paper provide guidelines for the designing of millimeter wave dielectric waveguide antenna array.

  14. Millimeter Wave Nondestructive Evaluation of Corrosion Under Paint in Steel Structures

    SciTech Connect

    Kharkovsky, S.; Zoughi, R.

    2006-03-06

    Millimeter wave nondestructive evaluation techniques have shown great potential for detection of corrosion under paint in steel structures. They may also provide for detection of other anomalies associated with the corrosion process such as precursor pitting. This paper presents the results of an extensive investigation spanning a frequency range of 30-100 GHz and using magnitude- and phase-sensitive reflectometers. Using 2D automated scanning mechanisms, raster images of two corrosion patches are produced showing the spatial resolution capabilities of these systems as well as their potential for evaluating localized corrosion severity.

  15. Limitations on millimeter-wave power generation with spiraling electron beams.

    NASA Technical Reports Server (NTRS)

    Kulke, B.

    1972-01-01

    A study is made of the suitability of the interaction between a thin, solid, spiraling electron beam of 5-15-kV energy and a microwave cavity, for the purpose of generating watts of CW millimeter-wave power. The effect of finite energy spread in the electron beam is considered both theoretically and experimentally. Measured results are given for a prototype device operating at 9.4 GHz. Power outputs of 5 W and electronic efficiencies near 2% have been obtained. The data agree well with the theory, subject to some ambiguity in the energy-distribution parameters. The performance is strongly limited by the energy spread in the beam.

  16. Identifying explosives by dielectric properties obtained through wide-band millimeter-wave illumination

    NASA Astrophysics Data System (ADS)

    Weatherall, James C.; Barber, Jeffrey; Smith, Barry T.

    2015-05-01

    A method for extracting dielectric constant from free-space 18 - 40 GHz millimeter-wave reflection data is demonstrated. The reflection coefficient is a function of frequency because of propagation effects, and numerically fitting data to a theoretical model based on geometric optics gives a solution for the complex dielectric constant and target thickness. The discriminative value is illustrated with inert substances and military sheet explosive. In principle, the measurement of reflectivity across multiple frequencies can be incorporated into Advanced Imaging Technology (AIT) systems to automatically identify the composition of anomalies detected on persons at screening checkpoints.

  17. Human Skin as Arrays of Helical Antennas in the Millimeter and Submillimeter Wave Range

    NASA Astrophysics Data System (ADS)

    Feldman, Yuri; Puzenko, Alexander; Ben Ishai, Paul; Caduff, Andreas; Agranat, Aharon J.

    2008-03-01

    Recent studies of the minute morphology of the skin by optical coherence tomography showed that the sweat ducts in human skin are helically shaped tubes, filled with a conductive aqueous solution. A computer simulation study of these structures in millimeter and submillimeter wave bands show that the human skin functions as an array of low-Q helical antennas. Experimental evidence is presented that the spectral response in the sub-Terahertz region is governed by the level of activity of the perspiration system. It is also correlated to physiological stress as manifested by the pulse rate and the systolic blood pressure.

  18. High-performance packaging for monolithic microwave and millimeter-wave integrated circuits

    NASA Technical Reports Server (NTRS)

    Shalkhauser, K. A.; Li, K.; Shih, Y. C.

    1992-01-01

    Packaging schemes are developed that provide low-loss, hermetic enclosure for enhanced monolithic microwave and millimeter-wave integrated circuits. These package schemes are based on a fused quartz substrate material offering improved RF performance through 44 GHz. The small size and weight of the packages make them useful for a number of applications, including phased array antenna systems. As part of the packaging effort, a test fixture was developed to interface the single chip packages to conventional laboratory instrumentation for characterization of the packaged devices.

  19. A selective pyroelectric detector of millimeter-wave radiation with an ultrathin resonant meta-absorber

    NASA Astrophysics Data System (ADS)

    Paulish, A. G.; Kuznetsov, S. A.

    2016-11-01

    The results of experimental investigations of spectral and amplitude-frequency characteristics for a discrete wavelength-selective pyroelectric detector operating in the millimetric band are presented. The high spectral selectivity is attained due to integrating the detector with a resonant meta-absorber designed for a close-to-unity absorptivity at 140 GHz. It is demonstrated that the use of this meta-absorber provides an opportunity to construct small-sized and inexpensive multispectral polarization-sensitive systems for radiation detection in the range of millimeter and submillimeter waves.

  20. Dual-band double-negative-index fishnet metamaterial at millimeter-waves.

    PubMed

    Navarro-Cía, Miguel; García-Meca, Carlos; Beruete, Miguel; Martínez, Alejandro; Sorolla, Mario

    2011-11-01

    An effective negative refractive index (NRI) is demonstrated and experimentally verified for the first two propagation bands of a fishnet-like metamaterial at millimeter-wave frequencies. The dual-band NRI behavior is achieved by engineering the diffraction order (±1, ±1) associated with the internal mode supported between holey layers to correspond with the second propagation band. In addition to the experimental interferometric technique that accounts for the handedness of the propagation, numerical results are given to predict the dual-band effective NRI and to confirm dual-band negative refraction for a prism composed of the proposed metamaterial.