Imaging of spatial distributions of the millimeter wave intensity by using visible continuum radiation from a discharge in a Cs–Xe mixture. Part I: Review of the method and its fundamentals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gitlin, M. S., E-mail: gitlin@appl.sci-nnov.ru

The first part of the review is presented which is dedicated to the time-resolved method of imaging and measuring the spatial distribution of the intensity of millimeter waves by using visible continuum (VC) emitted by the positive column (PC) of a dc discharge in a mixture of cesium vapor with xenon. The review focuses on the operating principles, fundamentals, and applications of this new technique. The design of the discharge tube and experimental setup used to create a wide homogeneous plasma slab with the help of the Cs–Xe discharge at a gas pressure of 45 Torr are described. The millimeter-wavemore » effects on the plasma slab are studied experimentally. The mechanism of microwave-induced variations in the VC brightness and the causes of violation of the local relation between the VC brightness and the intensity of millimeter waves are discussed. Experiments on the imaging of the field patterns of horn antennas and quasi-optical beams demonstrate that this technique can be used for good-quality imaging of millimeter-wave beams in the entire millimeter-wavelength band. The method has a microsecond temporal resolution and a spatial resolution of about 2 mm. Energy sensitivities of about 10 μJ/cm{sup 2} in the Ka-band and about 200 μJ/cm{sup 2} in the D-band have been demonstrated.« less

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.

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.

Threat detection in desert environment with passive millimeter-wave sensor

NASA Astrophysics Data System (ADS)

Wilson, John P.; Schuetz, Christopher A.; Martin, Richard D.; Dillon, Thomas E.; Murakowski, Maciej; Prather, Dennis W.

2011-06-01

A new technique for improvised explosive device (IED) creation uses an explosive device buried in foam and covered in a layer of dirt. These devices are difficult to detect visually, however, their material characteristics make them detectable by passive millimeter-wave (pmmW) sensors. Results are presented from a test using a mock IED and an outdoor set-up consisting of two mock IEDs on a dirt background. The results show that the mock IEDs produces a millimeter-wave signature which is distinguishable from the background surrounding the mock IEDs. Simulations based on the measured data are presented and a design for a future vehicle mounted sensor is shown.

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.

Millimeter-wave signal generation for a wireless transmission system based on on-chip photonic integrated circuit structures.

PubMed

Guzmán, R; Carpintero, G; Gordon, C; Orbe, L

2016-10-15

We demonstrate and compare two different photonic-based signal sources for generating the carrier wave in a wireless communication link operating in the millimeter-wave range. The first signal source uses the optical heterodyne technique to generate a 113 GHz carrier wave frequency, while the second employs a different technique based on a pulsed mode-locked source with 100 GHz repetition rate frequency. The two optical sources were fabricated in a multi-project wafer run from an active/passive generic integration platform process using standardized building blocks, including multimode interference reflectors which allow us to define the structures on chip, without the need for cleaved facet mirrors. We highlight the superior performance of the mode-locked sources over an optical heterodyne technique. Error-free transmission was achieved in this experiment.

Comparison of Focused and Near-Field Imaging of Spray on Foam Insulation (SOFI) at Millimeter Wave Frequencies

NASA Technical Reports Server (NTRS)

Kharkovshy, S.; Zoughi, R.; Hepburn, F. L.

2007-01-01

Millimeter wave imaging techniques can provide high spatial-resolution images of various composites. Lens antennas may be incorporated into the imaging system to provide a small incident beam footprint. Another approach may involve the use of horn antennas, which if operating in their near-fields, images with reasonably high spatial-resolutions may also be obtained. This paper gives a comparison between such near-field and focused far-field imaging of the Space Shuttle Spray on Foam Insulation (SOFI) used in its external fuel tank at millimeter wave frequencies. Small horn antennas and lens antennas with relatively long depth of focus were used in this investigation.

Millimeter-wave monolithic integrated circuit characterization by a picosecond optoelectronic technique

NASA Astrophysics Data System (ADS)

Hung, Hing-Loi A.; Smith, Thane; Huang, Ho C.; Polak-Dingels, Penny; Webb, Kevin J.

1989-08-01

The characterization of microwave and millimeter-wave monolithic integrated circits (MIMICs) using picosecond pulse-sampling techniques is developed with emphasis on improving broadband coverage and measurement accuracy. GaAs photoconductive swithces are used for signal generation and sampling operations. The measured time-domain response allows the spectral transfer function of the MIMIC to be obtained. This measurement technique is verified by characterization of the frequency response (magnitude and phase) of a reference 50-ohm microstrip line and a two-stage Ka-band MIMIC amplifier. The measured broadband results agree with those obtained from conventional frequency-domain measurements using a network analyzer. The application of this optical technique to on-wafer MIMIC characterization is described.

International Conference on Antennas and Propagation (ICAP 89), 6th, University of Warwick, Coventry, England, Apr. 4-7, 1989, Proceedings. Part 1 - Antennas. Part 2 - Propagation

NASA Astrophysics Data System (ADS)

Various papers on antennas and propagation are presented. The general topics addressed include: phased arrays; reflector antennas; slant path propagation; propagation data for HF radio systems performance; satellite and earth station antennas; radio propagation in the troposphere; propagation data for HF radio systems performance; microstrip antennas; rain radio meteorology; conformal antennas; horns and feed antennas; low elevation slant path propagation; radio millimeter wave propagation; array antennas; propagation effects on satellite mobile, satellite broadcast, and aeronautical systems; ionospheric irregularities and motions; adaptive antennas; transient response; measurement techniques; clear air radio meteorology; ionospheric and propagation modeling; millimeter wave and lens antennas; electromagnetic theory and numerical techniques; VHF propagation modeling, system planning methods; radio propagation theoretical techniques; scattering and diffraction; transhorizon rain scatter effects; ELF-VHF and broadcast antennas; clear air millimeter propagation; scattering and frequency-selective surfaces; antenna technology; clear air transhorizon propagation.

Antenna-coupled Superconducting Bolometers for Observations of the Cosmic Microwave Background Polarization

NASA Astrophysics Data System (ADS)

Myers, Michael James

We describe the development of a novel millimeter-wave cryogenic detector. The device integrates a planar antenna, superconducting transmission line, bandpass filter, and bolometer onto a single silicon wafer. The bolometer uses a superconducting Transition-Edge Sensor (TES) thermistor, which provides substantial advantages over conventional semiconductor bolometers. The detector chip is fabricated using standard micro-fabrication techniques. This highly-integrated detector architecture is particularly well-suited for use in the de- velopment of polarization-sensitive cryogenic receivers with thousands of pixels. Such receivers are needed to meet the sensitivity requirements of next-generation cosmic microwave background polarization experiments. The design, fabrication, and testing of prototype array pixels are described. Preliminary considerations for a full array design are also discussed. A set of on-chip millimeter-wave test structures were developed to help understand the performance of our millimeter-wave microstrip circuits. These test structures produce a calibrated transmission measurement for an arbitrary two-port circuit using optical techniques, rather than a network analyzer. Some results of fabricated test structures are presented.

Microwave and Millimeter Wave Imaging of the Space Shuttle External Fuel Tank Spray on Foam Insulation (SOFI) using Synthetic Aperture Focusing Techniques (SAFT}

NASA Technical Reports Server (NTRS)

Case, J. T.; Robbins, J.; Kharkivskiy, S.; Hepburn, F.; Zoughi, R.

2005-01-01

The Space Shuttle Columbia s catastrophic failure is thought to have been caused by a dislodged piece of external tank spray on foam insulation (SOFI) striking the left wing of the orbiter causing significant damage to some of the reinforced carbodcarbon leading edge wing panels. Microwave and millimeter wave nondestructive evaluation methods have shown great potential for inspecting SOFI for the purpose of detecting anomalies such as small air voids that may cause separation of the SOFI from the external tank during a launch. These methods are capable of producing relatively high-resolution images of the interior of SOFI particularly when advanced imaging algorithms are incorporated into the overall system. To this end, synthetic aperture focusing techniques (SAFT) are being developed. This paper presents some of the preliminary results of this investigation using SAFT-based methods and microwave holography at relatively low frequencies illustrating their potential capabilities for operation at millimeter wave frequencies.

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.

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.

Computer aided design of monolithic microwave and millimeter wave integrated circuits and subsystems

NASA Astrophysics Data System (ADS)

Ku, Walter H.

1989-05-01

The objectives of this research are to develop analytical and computer aided design techniques for monolithic microwave and millimeter wave integrated circuits (MMIC and MIMIC) and subsystems and to design and fabricate those ICs. Emphasis was placed on heterojunction-based devices, especially the High Electron Mobility Transition (HEMT), for both low noise and medium power microwave and millimeter wave applications. Circuits to be considered include monolithic low noise amplifiers, power amplifiers, and distributed and feedback amplifiers. Interactive computer aided design programs were developed, which include large signal models of InP MISFETs and InGaAs HEMTs. Further, a new unconstrained optimization algorithm POSM was developed and implemented in the general Analysis and Design program for Integrated Circuit (ADIC) for assistance in the design of largesignal nonlinear circuits.

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.

Millimeter Wave Detection of Localized Anomalies in the Space Shuttle External Fuel Tank Insulating Foam and Acreage Heat Tiles

NASA Technical Reports Server (NTRS)

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

2005-01-01

The Space Shuttle Columbia's catastrophic accident emphasizes the growing need for developing and applying effective, robust and life-cycle oriented nondestructive testing (NDT) methods for inspecting the shuttle external fuel tank spray on foam insulation (SOFI) and its protective acreage heat tiles. Millimeter wave NDT techniques were one of the methods chosen for evaluating their potential for inspecting these structures. Several panels with embedded anomalies (mainly voids) were produced and tested for this purpose. Near-field and far-field millimeter wave NDT methods were used for producing millimeter wave images of the anomalies in SOFI panel and heat tiles. This paper presents the results of an investigation for the purpose of detecting localized anomalies in two SOFI panels and a set of heat tiles. To this end, reflectometers at a relatively wide range of frequencies (Ka-band (26.5 - 40 GHz) to W-band (75 - 110 GHz)) and utilizing different types of radiators were employed. The results clearly illustrate the utility of these methods for this purpose.

A ground-based technique for millimeter wave spectroscopic observations of stratospheric trace constituents

NASA Technical Reports Server (NTRS)

Parrish, A.; Dezafra, R. L.; Solomon, P. M.; Barrett, J. W.

1988-01-01

Recent concern over possible long term stratospheric changes caused by the introduction of man-made compounds has increased the need for instrumentation that can accurately measure stratospheric minor constituents. The technique of radio spectroscopy at millimeter wavelengths was first used to observe rotational transitions of stratospheric ozone nearly two decades ago, but has not been highly developed until recently. A ground-based observing technique is reported which employs a millimeter-wave superheterodyne receiver and multichannel filter spectrometer for measurements of stratospheric constituents that have peak volume mixing ratios that are less than 10 to the -9th, more than 3 orders of magnitude less than that for ozone. The technique is used for an extensive program of observations of stratospheric chlorine monoxide and also for observations of other stratospheric trace gases such as (O-16)3, vibrationally excited (O-16)3, (O-18)2(O-16), N2O, HO2, and HCN. In the present paper, analysis of the observing technique is given, including the method of calibration and analysis of sources of error. The technique is found to be a reliable means of observing and monitoring important stratospheric trace constituents.

Energy-efficient process-stacking multiplexing access for 60-GHz mm-wave wireless personal area networks.

PubMed

Estevez, Claudio; Kailas, Aravind

2012-01-01

Millimeter-wave technology shows high potential for future wireless personal area networks, reaching over 1 Gbps transmissions using simple modulation techniques. Current specifications consider dividing the spectrum into effortlessly separable spectrum ranges. These low requirements open a research area in time and space multiplexing techniques for millimeter-waves. In this work a process-stacking multiplexing access algorithm is designed for single channel operation. The concept is intuitive, but its implementation is not trivial. The key to stacking single channel events is to operate while simultaneously obtaining and handling a-posteriori time-frame information of scheduled events. This information is used to shift a global time pointer that the wireless access point manages and uses to synchronize all serviced nodes. The performance of the proposed multiplexing access technique is lower bounded by the performance of legacy TDMA and can significantly improve the effective throughput. Work is validated by simulation results.

Carbon loaded Teflon (CLT): a power density meter for biological experiments using millimeter waves.

PubMed

Allen, Stewart J; Ross, James A

2007-01-01

The standard technique for measurement of millimeter wave fields utilizes an open-ended waveguide attached to a HP power meter. The alignment of the waveguide with the propagation (K) vector is critical to making accurate measurements. Using this technique, it is difficult and time consuming to make a detailed map of average incident power density over areas of biological interest and the spatial resolution of this instrument does not allow accurate measurements in non-uniform fields. For biological experiments, it is important to know the center field average incident power density and the distribution over the exposed area. Two 4 ft x 4 ft x 1/32 inch sheets of carbon loaded Teflon (CLT) (one 15% carbon and one 25% carbon) were procured and a series of tests to determine the usefulness of CLT in defining fields in the millimeter wavelength range was initiated. Since the CLT was to be used both in the laboratory, where the environment was well controlled, and in the field, where the environment could not be controlled, tests were made to determine effects of change in environmental conditions on ability to use CLT as a millimeter wave dosimeter. The empirical results of this study indicate CLT to be an effective dosimeter for biological experiments both in the laboratory and in the field.

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.

The impact of environmental factors on the performance of millimeter wave seekers in smart munitions

NASA Astrophysics Data System (ADS)

Hager, R.

1987-08-01

An assessment has been made of the degradation in performance of horizontal-glide smart munitions incorporating millimeter wave seekers operating in three types of environments. Atmospheric effects are shown to degrade performance appreciably only in very severe weather conditions. Electromagnetic line-of-sight masking due to foliage (forest canopy and tree-lined roads) will limit submunition usage and may be a potential problem. The most serious problem involves the confident detection of military vehicles in the presence of land clutter. Standard signal processing techniques involving signal amplitude and signal averaging are not likely to be adequate for detection. Observations regarding more sophisticated techniques and the current state of research are included.

Millimeter-Wave GaN MMIC Integration with Additive Manufacturing

NASA Astrophysics Data System (ADS)

Coffey, Michael

This thesis addresses the analysis, design, integration and test of microwave and millimeter-wave monolithic microwave integrated circuits (MMIC or MMICs). Recent and ongoing progress in semiconductor device fabrication and MMIC processing technology has pushed the upper limit in MMIC frequencies from millimeter-wave (30-300 GHz) to terahertz (300-3000 GHz). MMIC components operating at these frequencies will be used to improve the sensitivity and performance of radiometers, receivers for communication systems, passive remote sensing systems, transceivers for radar instruments and radio astronomy systems. However, a serious hurdle in the utilization of these MMIC components, and a main topic presented in this thesis, is the development and reliable fabrication of practical packaging techniques. The focus of this thesis is the investigation of first, the design and analysis of microwave and millimeter-wave GaN MMICs and second, the integration of those MMICs into usable waveguide components. The analysis, design and testing of various X-band (8-12 GHz) thru H-band (170-260 GHz) GaN MMIC power amplifier (PA or PAs), including a V-band (40-75 GHz) voltage controlled oscillator, is the majority of this work. Several PA designs utilizing high-efficiency techniques are analyzed, designed and tested. These examples include a 2nd harmonic injection amplifier, a Class-E amplifier fabricated with a GaN-on-SiC 300 GHz fT process, and an example of the applicability of supply-modulation with a Doherty power amplifier, all operating at 10 GHz. Two H-band GaN MMIC PAs are designed, one with integrated CPW-to-waveguide transitions for integration. The analysis of PA stability is especially important for wideband, high- fT devices and a new way of analyzing stability is explored and experimentally validated. Last, the challenges of integrating MMICs operating at millimeter-wave frequencies are discussed and assemblies using additive and traditional manufacturing are demonstrated.

Basic examination of a technique to visualize space filled with dense smoke using millimeter-wave radar

NASA Astrophysics Data System (ADS)

Omine, Yukio; Sakai, Masaki; Aoki, Yoshimitsu; Takagi, Mikio

2004-10-01

In recent years, crisis management in response to terrorist attacks and natural disasters, as well as accelerating rescue operations has become an important issue. Rescue operations greatly influence human lives, and require the ability to accurately and swiftly communicate information as well as assess the status of the site. Currently, considerable amount of research is being conducted for assisting rescue operations, with the application of various engineering techniques such as information technology and radar technology. In the present research, we believe that assessing the status of the site is most crucial in rescue and firefighting operations at a fire disaster site, and aim to visualize the space that is smothered with dense smoke. In a space filled with dense smoke, where visual or infrared sensing techniques are not feasible, three-dimensional measurements can be realized using a compact millimeter wave radar device combined with directional information from a gyro sensor. Using these techniques, we construct a system that can build and visualize a three-dimensional geometric model of the space. The final objective is to implement such a system on a wearable computer, which will improve the firefighters' spatial perception, assisting them in the baseline assessment and the decision-making process. In the present paper, we report the results of the basic experiments on three-dimensional measurement and visualization of a space that is smoke free, using a millimeter wave radar.

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.

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.

Low-Power Testing of Losses in Millimeter-Wave Transmission Lines for High-Power Applications

PubMed Central

Han, S. T.; Comfoltey, E. N.; Shapiro, M. A.; Sirigiri, J. R.; Tax, D. S.; Temkin, R. J.; Woskov, P. P.; Rasmussen, D. A.

2008-01-01

We report the measurement of small losses in transmission line (TL) components intended for high-power millimeter-wave applications. Measurements were made using two different low-power techniques: a coherent technique using a vector network analyzer (VNA) and an incoherent technique using a radiometer. The measured loss in a 140 GHz 12.7 mm diameter TL system, consisting of 1.7 m of circular corrugated waveguide and three miter bends, is dominated by the miter bend loss. The measured loss was 0.3±0.1 dB per miter bend using a VNA; and 0.22±0.1 dB per miter bend using a radiometer. Good agreement between the two measurement techniques implies that both are useful for measuring small losses. To verify the methodology, the VNA technique was employed to measure the extremely small transmission loss in a 170 GHz ITER prototype TL system consisting of three lengths of 1 m, 63.5 mm diameter, circular corrugated waveguide and two miter bends. The measured loss of 0.05±0.02 dB per miter bend may be compared with the theoretical loss of 0.027 dB per miter bend. These results suggest that low-power testing of TL losses, utilizing a small, simple TL system and a VNA, is a reliable method for evaluating performance of low-loss millimeter-wave TL components intended for use in high-power applications. PMID:19081774

Ultrasonic, microwave, and millimeter wave inspection techniques for adhesively bonded stacked open honeycomb core composites

NASA Astrophysics Data System (ADS)

Thomson, Clint D.; Cox, Ian; Ghasr, Mohammad Tayeb Ahmed; Ying, Kuang P.; Zoughi, Reza

2015-03-01

Honeycomb sandwich composites are used extensively in the aerospace industry to provide stiffness and thickness to lightweight structures. A common fabrication method for thick, curved sandwich structures is to stack and bond multiple honeycomb layers prior to machining core curvatures. Once bonded, each adhesive layer must be inspected for delaminations and the presence of unwanted foreign materials. From a manufacturing and cost standpoint, it can be advantageous to inspect the open core prior to face sheet closeout in order to reduce end-article scrap rates. However, by nature, these honeycomb sandwich composite structures are primarily manufactured from low permittivity and low loss materials making detection of delamination and some of the foreign materials (which also are low permittivity and low loss) quite challenging in the microwave and millimeter wave regime. Likewise, foreign materials such as release film in adhesive layers can be sufficiently thin as to not cause significant attenuation in through-transmission ultrasonic signals, making them difficult to detect. This paper presents a collaborative effort intended to explore the efficacy of different non-contact NDI techniques for detecting flaws in a stacked open fiberglass honeycomb core panel. These techniques primarily included air-coupled through-transmission ultrasonics, single-sided wideband synthetic aperture microwave and millimeter-wave imaging, and lens-focused technique. The goal of this investigation has been to not only evaluate the efficacy of these techniques, but also to determine their unique advantages and limitations for evaluating parameters such as flaw type, flaw size, and flaw depth.

A hybrid MAC protocol design for energy-efficient very-high-throughput millimeter wave, wireless sensor communication networks

NASA Astrophysics Data System (ADS)

Jian, Wei; Estevez, Claudio; Chowdhury, Arshad; Jia, Zhensheng; Wang, Jianxin; Yu, Jianguo; Chang, Gee-Kung

2010-12-01

This paper presents an energy-efficient Medium Access Control (MAC) protocol for very-high-throughput millimeter-wave (mm-wave) wireless sensor communication networks (VHT-MSCNs) based on hybrid multiple access techniques of frequency division multiplexing access (FDMA) and time division multiplexing access (TDMA). An energy-efficient Superframe for wireless sensor communication network employing directional mm-wave wireless access technologies is proposed for systems that require very high throughput, such as high definition video signals, for sensing, processing, transmitting, and actuating functions. Energy consumption modeling for each network element and comparisons among various multi-access technologies in term of power and MAC layer operations are investigated for evaluating the energy-efficient improvement of proposed MAC protocol.

Millimeter Wave Radar Applications to Weapons Systems

DTIC Science & Technology

1976-06-01

meter wave region compared with the high attenuation in the optical region. It is this unique characteristic of millimeter waves to penetrate fog...miiliaeter wave radars in graund-to-- air , ground-to-ground, and air -to-ground weapons systems aye presented. The advantages and limitation~s¶ of operating...MILLIMETER WAVE RADAR CHARACTERISTICS ..... ............ .. 27 A, General ................ ......................... ... 27 B. Ground-to- Air Millimeter

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.

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. Copyright © 2012 Wiley Periodicals, Inc.

Full-duplex bidirectional transmission of 10-Gb/s millimeter-wave QPSK signal in E-band optical wireless link.

PubMed

Fang, Yuan; Yu, Jianjun; Chi, Nan; Xiao, Jiangnan

2014-01-27

We experimentally demonstrated full-duplex bidirectional transmission of 10-Gb/s millimeter-wave (mm-wave) quadrature phase shift keying (QPSK) signal in E-band (71-76 GHz and 81-86 GHz) optical wireless link. Single-mode fibers (SMF) are connected at both sides of the antenna for uplink and downlink which realize 40-km SMF and 2-m wireless link for bidirectional transmission simultaneously. We utilized multi-level modulation format and coherent detection in such E-band optical wireless link for the first time. Mm-wave QPSK signal is generated by photonic technique to increase spectrum efficiency and received signal is coherently detected to improve receiver sensitivity. After the coherent detection, digital signal processing is utilized to compensate impairments of devices and transmission link.

Wide-Bandwidth, Wide-Beamwidth, High-Resolution, Millimeter-Wave Imaging for Concealed Weapon Detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheen, David M.; Fernandes, Justin L.; Tedeschi, Jonathan R.

2013-06-12

Active millimeter-wave imaging is currently being used for personnel screening at airports and other high-security facilities. The lateral resolution, depth resolution, clothing penetration, and image illumination quality obtained from next-generation systems can be significantly enhanced through the selection the aperture size, antenna beamwidth, center frequency, and bandwidth. In this paper, the results of an extensive imaging trade study are presented using both planar and cylindrical three-dimensional imaging techniques at frequency ranges of 10-20 GHz, 10 – 40 GHz, 40 – 60 GHz, and 75 – 105 GHz

Millimeter-wave studies

NASA Technical Reports Server (NTRS)

Allen, Kenneth C.

1988-01-01

Progress on millimeter-wave propagation experiments in Hawaii is reported. A short path for measuring attenuation in rain at 9.6, 28.8, 57.6, and 96.1 GHz is in operation. A slant path from Hilo to the top of Mauna Kea is scheduled. On this path, scattering from rain and clouds that may cause interference for satellites closely spaced in geosynchronous orbit will be measured at the same frequencies at 28.8 and 96.1 GHz. In addition the full transmission matrix will be measured at the same frequencies on the slant path. The technique and equipment used to measure the transmission matrix are described.

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.

Fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave and free-space-optics architecture with an adaptive diversity combining technique.

PubMed

Zhang, Junwen; Wang, Jing; Xu, Yuming; Xu, Mu; Lu, Feng; Cheng, Lin; Yu, Jianjun; Chang, Gee-Kung

2016-05-01

We propose and experimentally demonstrate a novel fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave (MMW) and free-space-optics (FSO) architecture using an adaptive combining technique. Both 60 GHz MMW and FSO links are demonstrated and fully integrated with optical fibers in a scalable and cost-effective backhaul system setup. Joint signal processing with an adaptive diversity combining technique (ADCT) is utilized at the receiver side based on a maximum ratio combining algorithm. Mobile backhaul transportation of 4-Gb/s 16 quadrature amplitude modulation frequency-division multiplexing (QAM-OFDM) data is experimentally demonstrated and tested under various weather conditions synthesized in the lab. Performance improvement in terms of reduced error vector magnitude (EVM) and enhanced link reliability are validated under fog, rain, and turbulence conditions.

Tolerance of the frequency deviation of LO sources at a MIMO system

NASA Astrophysics Data System (ADS)

Xiao, Jiangnan; Li, Xingying; Zhang, Zirang; Xu, Yuming; Chen, Long; Yu, Jianjun

2015-11-01

We analyze and simulate the tolerance of frequency offset at a W-band optical-wireless transmission system. The transmission system adopts optical polarization division multiplexing (PDM), and multiple-input multiple-output (MIMO) reception. The transmission signal adopts optical quadrature phase shift keying (QPSK) modulation, and the generation of millimeter-wave is based on the optical heterodyning technique. After 20-km single-mode fiber-28 (SMF-28) transmission, tens of Gb/s millimeter-wave signal is delivered. At the receiver, two millimeter-wave signals are down-converted into electrical intermediate-frequency (IF) signals in the analog domain by mixing with two electrical local oscillators (LOs) with different frequencies. We investigate the different frequency LO effect on the 2×2 MIMO system performance for the first time, finding that the process during DSP of implementing frequency offset estimation (FOE) before cascaded multi-modulus-algorithm (CMMA) equalization can get rid of the inter-channel interference (ICI) and improve system bit-error-ratio (BER) performance in this type of transmission system.

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.

Investigation of Passive Atmospheric Sounding Using Millimeter- and Submillimeter- Wavelength Channels

NASA Technical Reports Server (NTRS)

Gasiewski, Albin J.

1996-01-01

This report summarizes progress made during the period from July 1, 1994 through June 30, 1996 on the development of satellite-based observational techniques for high resolution imaging of precipitation and sounding of atmospheric ice and water vapor using passive microwave radiometers in the millimeter (MMW)- and submillimeter (SMMW)-wavelength. This is being achieved by radiative transfer modeling a millimeter and submillimeter wave frequencies and by the development and operation of an airborne millimeter wave imaging radiometer (MIR). The MIR has been used in both airborne and ground-based experiments. Its primary application is to provide calibrated radiometric imagery to verify MMW and SMMW radiative transfer models in clear air, cloud, and precipitation and to develop retrieval techniques using MMW and SMMW channels. The MIR imagery over convective storm cells has been used to illustrate the potentially useful cloud and water vapor sensing and storm-cell mapping capabilities of SMMW channels. The radiometric data has also been used to analyze radiative transfer model discrepancies caused by water vapor errors in radiosondes. The MMW and SMMW channels can be used to extend the altitude that water vapor sounding can be performed up into the lower stratosphere. Together, the use of both SMMW and MMW channels are expected to provide additional observational degrees of freedom related to cloud ice particle size.

Microwave and Millimeter Wave Imaging of the Space Shuttle External Fuel Tank Spray on Foam Insulation (SOFI) Using Synthetic Aperture Focusing Techniques (SAFT)

NASA Technical Reports Server (NTRS)

Case, J. T.; Robbins, J.; Kharkovshy, S.; Hepburn, F. L.; Zoughi, R.

2005-01-01

The Space Shuttle Columbia's catastrophic failure is thought to have been caused by a dislodged piece of external tank SOFI (Spray On Foam Insulation) striking the left wing of the orbiter causing significant damage to some of the reinforced carbodcarbon leading edge wing panels. Microwave and millimeter wave nondestructive evaluation methods, have shown great potential for inspecting the SOFI for the purpose of detecting anomalies such as small voids that may cause separation of the foam from the external tank during the launch. These methods are capable of producing relatively high-resolution images of the interior of SOH particularly when advanced imaging algorithms are incorporated into the overall system. To this end, synthetic aperture focusing techniques are being deveioped for this purpose. These iechniqiies pradiice high-resolution images that are independent of the distance of the imaging probe to the SOFI with spatial resolution in the order of the half size of imaging probe aperture. At microwave and millimeter wave frequencies these apertures are inherently small resulting in high-resolution images. This paper provides the results of this investigation using 2D and 3D SAF based methods and holography. The attributes of these methods and a full discussion of the results will also be provided.

Universal test fixture for monolithic mm-wave integrated circuits calibrated with an augmented TRD algorithm

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.; Shalkhauser, Kurt A.

1989-01-01

The design and evaluation of a novel fixturing technique for characterizing millimeter wave solid state devices is presented. The technique utilizes a cosine-tapered ridge guide fixture and a one-tier de-embedding procedure to produce accurate and repeatable device level data. Advanced features of this technique include nondestructive testing, full waveguide bandwidth operation, universality of application, and rapid, yet repeatable, chip-level characterization. In addition, only one set of calibration standards is required regardless of the device geometry.

Microwave and millimeter wave dielectric permittivity and magnetic permeability of epsilon-gallium-iron-oxide nano-powders

NASA Astrophysics Data System (ADS)

Chao, Liu; Afsar, Mohammed N.; Ohkoshi, Shin-ichi

2015-05-01

In millimeter wave frequency range, hexagonal ferrites with high uniaxial anisotropic magnetic fields are used as absorbers. These ferrites include M-type barium ferrite (BaFe12O19) and strontium ferrite (SrFe12O19), 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 series of gallium-substituted ɛ-iron oxides (ɛ-GaxFe2-xO3) are synthesized, which have ferromagnetic resonant frequencies appearing over the frequency range of 30 GHz to 150 GHz. The ɛ-GaxFe2-xO3 is synthesized by the sol-gel method. The particle sizes are observed to be smaller than 100 nm. In this paper, in-waveguide transmission and reflection method and the free space magneto-optical approach have been employed to study these newly developed ɛ-GaxFe2-xO3 particles in millimeter waves. These techniques enable to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the microwave and millimeter wave frequency range from single set of direct measurements. The complex dielectric permittivity and magnetic permeability spectra of ɛ-GaxFe2-xO3 are shown in this paper. Strong ferromagnetic resonances at different frequencies determined by the x parameter are found.

A cusp electron gun for millimeter wave gyrodevices

NASA Astrophysics Data System (ADS)

Donaldson, C. R.; He, W.; Cross, A. W.; Li, F.; Phelps, A. D. R.; Zhang, L.; Ronald, K.; Robertson, C. W.; Whyte, C. G.; Young, A. R.

2010-04-01

The experimental results of a thermionic cusp electron gun, to drive millimeter and submillimeter wave harmonic gyrodevices, are reported in this paper. Using a "smooth" magnetic field reversal formed by two coils this gun generated an annular-shaped, axis-encircling electron beam with 1.5 A current, and an adjustable velocity ratio α of up to 1.56 at a beam voltage of 40 kV. The beam cross-sectional shape and transported beam current were measured by a witness plate technique and Faraday cup, respectively. These measured results were found to be in excellent agreement with the simulated results using the three-dimensional code MAGIC.

A Millimeter Wave BPF using WG Mode High Permittivity Dielectric Resonators

NASA Astrophysics Data System (ADS)

Sato, Yosuke; Kogami, Yoshinori; Tomabechi, Yoshiro; Matsumura, Kazuhito

In this paper, a design technique of whispering gallery mode high Q value dielectric disk resonators for a millimeter-wave bandpass filter is described. To minimize the resonator size, some high permittivity materials are used. In this resonator design, unloaded Q value of an interested mode and the higher order modes are calculated and then optimum resonator size for the WG mode dielectric filter is determined. For a designed resonator, the higher order modes are hardly excited while the Q value of the fundamental mode can be maximized. Finally, some 3stage BPFs are constructed at 60GHz by using these designed resonators.

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.

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.

Advanced radiometric and interferometric milimeter-wave scene simulations

NASA Technical Reports Server (NTRS)

Hauss, B. I.; Moffa, P. J.; Steele, W. G.; Agravante, H.; Davidheiser, R.; Samec, T.; Young, S. K.

1993-01-01

Smart munitions and weapons utilize various imaging sensors (including passive IR, active and passive millimeter-wave, and visible wavebands) to detect/identify targets at short standoff ranges and in varied terrain backgrounds. In order to design and evaluate these sensors under a variety of conditions, a high-fidelity scene simulation capability is necessary. Such a capability for passive millimeter-wave scene simulation exists at TRW. TRW's Advanced Radiometric Millimeter-Wave Scene Simulation (ARMSS) code is a rigorous, benchmarked, end-to-end passive millimeter-wave scene simulation code for interpreting millimeter-wave data, establishing scene signatures and evaluating sensor performance. In passive millimeter-wave imaging, resolution is limited due to wavelength and aperture size. Where high resolution is required, the utility of passive millimeter-wave imaging is confined to short ranges. Recent developments in interferometry have made possible high resolution applications on military platforms. Interferometry or synthetic aperture radiometry allows the creation of a high resolution image with a sparsely filled aperture. Borrowing from research work in radio astronomy, we have developed and tested at TRW scene reconstruction algorithms that allow the recovery of the scene from a relatively small number of spatial frequency components. In this paper, the TRW modeling capability is described and numerical results are presented.

Tunable ferromagnetic resonance in La-Co substituted barium hexaferrites at millimeter wave frequencies

NASA Astrophysics Data System (ADS)

Korolev, Konstantin A.; Wu, Chuanjian; Yu, Zhong; Sun, Ke; Afsar, Mohammed N.; Harris, Vincent G.

2018-05-01

Transmittance measurements have been performed on La-Co substituted barium hexaferrites in millimeter waves. Broadband millimeter-wave measurements have been carried out using the free space quasi-optical spectrometer, equipped with a set of high power backward wave oscillators covering the frequency range of 30 - 120 GHz. Strong absorption zones have been observed in the millimeter-wave transmittance spectra of all La-Co substituted barium hexaferrites due to the ferromagnetic resonance. Linear shift of ferromagnetic resonance frequency as functions of La-Co substitutions have been found. Real and imaginary parts of dielectric permittivity of La-Co substituted barium hexaferrites have been calculated using the analysis of recorded high precision transmittance spectra. Frequency dependences of magnetic permeability of La-Co substituted barium hexaferrites, as well as saturation magnetization and anisotropy field have been determined based on Schlömann's theory for partially magnetized ferrites. La-Co substituted barium hexaferrites have been further investigated by DC magnetization to assess magnetic behavior and compare with millimeter wave data. Consistency of saturation magnetization determined independently by both millimeter wave absorption and DC magnetization have been found for all La-Co substituted barium hexaferrites. These materials seem to be quite promising as tunable millimeter wave absorbers, filters, circulators, based on the adjusting of their substitution parameters.

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.

A practical double-sided frequency selective surface for millimeter-wave applications

NASA Astrophysics Data System (ADS)

Mohyuddin, Wahab; Woo, Dong Sik; Choi, Hyun Chul; Kim, Kang Wook

2018-02-01

Analysis, design, and implementation of a practical, high-rejection frequency selective surface (FSS) are presented in this paper. An equivalent circuit model is introduced for predicting the frequency response of the FSS. The FSS consists of periodic square loop structures fabricated on both sides of the thin dielectric substrate by using the low-cost chemical etching technique. The proposed FSS possesses band-stop characteristics and is implemented to suppress the 170 GHz signal with attenuation of more than 45 dB with insensitivity to an angle of incident plane wave over 20°. Good agreement is observed among calculated, simulated, and measured results. The proposed FSS filter can be used in various millimeter-wave applications such as the protection of imaging diagnostic systems from high spurious input power.

Microfabricated Millimeter-Wave High-Power Vacuum Electronic Amplifiers

DTIC Science & Technology

2015-01-01

Applications filed 2012). In spite of the challenges, high power sources of electromagnetic radiation are needed in the mmW bands for advanced DoD...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... s of watts power range at several percent instantaneous bandwidth. Keywords: Traveling wave tube; millimeter wave; vacuum electron device

INVESTIGATION OF NEW CONCEPTS AND LINEAR BEAM TECHNIQUES FOR MICROWAVE POWER GENERATION.

DTIC Science & Technology

ARSENIC ALLOYS, MILLIMETER WAVES, CAVITY RESONATORS, ELECTRON GUNS, ELECTRON DENSITY, EPITAXIAL GROWTH, OSCILLATORS, S BAND , X BAND , GERMANIUM...ELECTRIC FIELDS, SCATTERING, BRILLOUIN ZONES, RUBY, ELECTROSTRICTION, IONIZATION, MICROWAVE OSCILLATORS, KLYSTRONS , EXPERIMENTAL DESIGN.

[Acoustic detection of absorption of millimeter-band electromagnetic waves in biological objects].

PubMed

Polnikov, I G; Putvinskiĭ, A V

1988-01-01

Principles of photoacoustic spectroscopy were applied to elaborate a new method for controlling millimeter electromagnetic waves absorption in biological objects. The method was used in investigations of frequency dependence of millimeter wave power absorption in vitro and in vivo in the commonly used experimental irradiation systems.

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.

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.

Multilevel photonic modules for millimeter-wave phased-array antennas

NASA Astrophysics Data System (ADS)

Paolella, Arthur C.; Bauerle, Athena; Joshi, Abhay M.; Wright, James G.; Coryell, Louis A.

2000-09-01

Millimeter wave phased array systems have antenna element sizes and spacings similar to MMIC chip dimensions by virtue of the operating wavelength. Designing modules in traditional planar packaing techniques are therefore difficult to implement. An advantageous way to maintain a small module footprint compatible with Ka-Band and high frequency systems is to take advantage of two leading edge technologies, opto- electronic integrated circuits (OEICs) and multilevel packaging technology. Under a Phase II SBIR these technologies are combined to form photonic modules for optically controlled millimeter wave phased array antennas. The proposed module, consisting of an OEIC integrated with a planar antenna array will operate on the 40GHz region. The OEIC consists of an InP based dual-depletion PIN photodetector and distributed amplifier. The multi-level module will be fabricated using an enhanced circuit processing thick film process. Since the modules are batch fabricated using an enhanced circuit processing thick film process. Since the modules are batch fabricated, using standard commercial processes, it has the potential to be low cost while maintaining high performance, impacting both military and commercial communications systems.

Laboratory measurements of microwave and millimeter-wave properties of planetary atmospheric constituents

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1989-01-01

Accurate data on microwave and millimeter-wave properties of potential planetary atmospheric constituents is critical for the proper interpretation of radio occultation measurements, and of radio astronomical observations of both continuum and spectral line emissions. Such data is also needed to correct for atmospheric effects on radar studies of surface reflectivity. Since the refractive and absorptive properties of atmospheric constituents often vary drastically from theoretically-predicted profiles, especially under the extreme conditions characteristic of the planetary atmosphere, laboratory measurements under simulated planetary conditions are required. This paper reviews the instrumentation and techniques used for laboratory measurement of the refractivity and absorptivity of atmospheric constituents at wavelengths longward of 1 mm, under simulated planetary conditions (temperature, pressure, and broadening gases). Techniques for measuring both gases and condensates are considered. Also reviewed are the relative accuracies of the various techniques. Laboratory measurements are reviewed which have already been made, and additional measurements which are needed for interpretation of data from Venus and the outer planets, are highlighted.

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.

Manipulation of Bloch surface waves: from subwavelength focusing to nondiffracting beam

NASA Astrophysics Data System (ADS)

Kim, Myun-Sik; Herzig, Hans Peter

2018-01-01

We present a different type of electromagnetic surface wave than a surface plasmon polariton (SPP), called Bloch surface wave (BSW). BSWs are sustained by dielectric multilayers, and therefore they do not suffer from dissipation. Their propagation length is unbeatably long, e.g., over several millimeters. Thanks to this feature, larger integrations of 2D photonic chips are realizable. To do this, 2D optical components and corresponding techniques are necessary to manipulate in-plane propagation of surface waves. We overview recent progresses of the BSW research on manipulation techniques and developed components. Our study will provide a good guideline of the BSW components for users.

Microwave Thermal Propulsion

NASA Technical Reports Server (NTRS)

Parkin, Kevin L. G.; Lambot, Thomas

2017-01-01

We have conducted research in microwave thermal propulsion as part of the space exploration access technologies (SEAT) research program, a cooperative agreement (NNX09AF52A) between NASA and Carnegie Mellon University. The SEAT program commenced on the 19th of February 2009 and concluded on the 30th of September 2015. The DARPA/NASA Millimeter-wave Thermal Launch System (MTLS) project subsumed the SEAT program from May 2012 to March 2014 and one of us (Parkin) served as its principal investigator and chief engineer. The MTLS project had no final report of its own, so we have included the MTLS work in this report and incorporate its conclusions here. In the six years from 2009 until 2015 there has been significant progress in millimeter-wave thermal rocketry (a subset of microwave thermal rocketry), most of which has been made under the auspices of the SEAT and MTLS programs. This final report is intended for multiple audiences. For researchers, we present techniques that we have developed to simplify and quantify the performance of thermal rockets and their constituent technologies. For program managers, we detail the facilities that we have built and the outcomes of experiments that were conducted using them. We also include incomplete and unfruitful lines of research. For decision-makers, we introduce the millimeter-wave thermal rocket in historical context. Considering the economic significance of space launch, we present a brief but significant cost-benefit analysis, for the first time showing that there is a compelling economic case for replacing conventional rockets with millimeter-wave thermal rockets.

Microwave and Millimeter Wave Imaging Using Synthetic Aperture Focusing and Holographical Techniques

NASA Technical Reports Server (NTRS)

Case, Joseph Tobias

2005-01-01

Microwave and millimeter wave nondestructive testing and evaluation (NDT&E) methods have shown great potential for determining material composition in composite structures, determining material thickness or debond thickness between two layers, and determining the location and size of flaws, defects, and anomalies. The same testing methods have also shown great potential to produce relatively high-resolution images of voids inside Spray On Foam Insulation (SOFI) test panels using real focused methods employing lens antennas. An alternative to real focusing methods are synthetic focusing methods. The essence of synthetic focusing is to match the phase of the scattered signal to measured points spaced regularly on a plane. Many variations of synthetic focusing methods have already been developed for radars, ultrasonic testing applications, and microwave concealed weapon detection. Two synthetic focusing methods were investigated; namely, a) frequency-domain synthetic aperture focusing technique (FDSAFT), and b) wide-band microwave holography. These methods were applied towards materials whose defects were of low dielectric contrast like air void in SOFI. It is important to note that this investigation used relatively low frequencies from 8.2 GHz to 26.5 GHz that are not conducive for direct imaging of the SOFI. The ultimate goal of this work has been to demonstrate the capability of these methods before they are applied to much higher frequencies such as the millimeter wave frequency spectrum (e.g., 30-300 GHz).

Inspection of the Space Shuttle External Tank SOFI Using Near-Field and Focused Millimeter Wave Nondestructive Testing Techniques

NASA Technical Reports Server (NTRS)

Kharkovsky, S.; Hepburn, F.; Walker, J.; Zoughi, R.

2005-01-01

The Space Shuttle Columbia's catastrophic failure has been attributed to a piece of external tank SOFI (Spray On Foam Insulation) striking the left wing of the orbiter causing significant damage to some of the reinforced carbon/carbon leading edge wing panels. Subsequently, several nondestructive testing (NDT) techniques have been considered for inspecting the external tank. One such method involves using millimeter waves which have been shown to easily penetrate through the foam and provide high resolution images of its interior structures. This paper presents the results of inspecting three different SOFI covered panels by reflectometers at millimeter wave frequencies, specifically at 100 GHz. Each panel was fitted with various embedded anomalies/inserts representing voids and unbonds of diferent shapes, sizes and locations within each panel. In conjunction with these reJqectome&rs, radiators including a focused lens antenna and a small horn antenna were used. The focused lens antenna provided for a footprint diameter of approximately 1.25 cm (0.5") at 25.4 cm (10") away from the lens surface. The horn antenna was primarily operated in its near-field for obtaining relatively high resolution images. These images were produced using 2 0 scanning mechanisms. Discussions of the difference between the capabilities of these two types of antennas (radiators) for the purpose of inspecting the SOFI as it relates to the produced images are also presented.

High Resolution Millimeter Wave Inspecting of the Orbiter Acreage Heat Tiles of the Space Shuttle

NASA Technical Reports Server (NTRS)

Case, J. T.; Khakovsky, S.; Zoughi, r.; Hepburn, F.

2007-01-01

Presence of defects such as disbonds, delaminations, impact damage, in thermal protection systems can significantly reduce safety of the Space Shuttle and its crew. The physical cause of Space Shuttle Columbia's catastrophic failure was a breach in its thermal protection system, caused by a piece of external tank insulating foam separating from the external tank and striking the leading edge of the left wing of the orbiter. There is an urgent need for a rapid, robust and life-circle oriented nondestructive testing (NDT) technique capable of inspecting the external tank insulating foam as well as the orbiter's protective (acreage) heat tiles and its fuselage prior and subsequent to a launch. Such a comprehensive inspection technique enables NASA to perform life-cycle inspection on critical components of the orbiter and its supporting hardware. Consequently, NASA Marshall Space Flight Center initiated an investigation into several potentially viable NDT techniques for this purpose. Microwave and millimeter wave NDT methods have shown great potential to achieve these goals. These methods have been successfully used to produce images of the interior of various complex, thick and thin external tank insulating foam structures for real focused reflectometer at operating frequency from 50-100 GHz and for synthetic aperture techniques at Ku-band (12-18 GHz) and K-band (18-26 GHz). Preliminary results of inspecting heat tile specimens show that increasing resolution of the measurement system is an important issue. This paper presents recent results of an investigation for the purpose of detecting anomalies such as debonds and corrosion in metal substrate in complex multi-sectioned protective heat tile specimens using a real focused 150 GHz (D-band) reflectometer and wide-band millimeter wave holography at 33-50, GHz (Q-band).

Heterodyne Detection in MM & Sub-mm Waves Developed at Paris Observatory

NASA Astrophysics Data System (ADS)

Beaudin, G.; Encrenaz, P.

Millimeter and submillimeter-wave observations provide important informations for the studies of atmospheric chemistry and of astrochemistry (molecular clouds, stars formation, galactic study, comets and cosmology). But, these observations depend strongly on instrumentation techniques and on the site quality. New techniques or higher detector performances result in unprecedented observations and sometimes, the observational needs drive developments of new detector technologies, for example, superconducting junctions (SIS mixers) because of its high sensitivity in heterodyne detection in the millimeter and submillimeter wave range (100 GHz - 700 GHz), HEB (Hot Electron Bolometer) mixers which are being developed by several groups for application in THz observations. For the submillimetre wavelengths heterodyne receivers, the local oscillator (LO) is still a critical element. So far, solid state sources are often not powerful enough for most of the applications at millimetre or sub-millimetre wavelengths: large efforts using new planar components and integrated circuits on membrane substrate or new techniques (photomixing, QCL) are now in progress in few groups. The new large projects as SOFIA, Herschel, ALMA and the post-Herschel missions for astronomy, the other projects for aeronomy, meteorology (Megha-tropiques-Saphir) and for planetary science (ROSETTA, Mars exploration, ...), will benefit from the new developments to hunt more molecules.

Guided wave phenomena in millimeter wave integrated circuits and components

NASA Astrophysics Data System (ADS)

Itoh, Tatsuo

1993-01-01

Representative projects from Army Research Office are summarized. Following the narrative descriptions with appropriate illustrations, a complete list of articles published in scientific journals and those presented at national and international conferences is provided. Lists of personnel and advanced degrees are also included. The projects were carried out at The University of Texas at Austin and later at UCLA. Topics covered include: quasi-optical technique; active antenna; active filter; traveling wave transistor; slow wave, planar transmission line; and discontinuities.

Contactless measurement of electrical conductivity of semiconductor wafers using the reflection of millimeter waves

NASA Astrophysics Data System (ADS)

Ju, Yang; Inoue, Kojiro; Saka, Masumi; Abe, Hiroyuki

2002-11-01

We present a method for quantitative measurement of electrical conductivity of semiconductor wafers in a contactless fashion by using millimeter waves. A focusing sensor was developed to focus a 110 GHz millimeter wave beam on the surface of a silicon wafer. The amplitude and the phase of the reflection coefficient of the millimeter wave signal were measured by which electrical conductivity of the wafer was determined quantitatively, independent of the permittivity and thickness of the wafers. The conductivity obtained by this method agrees well with that measured by the conventional four-point-probe method.

Research in millimeter wave techniques

NASA Technical Reports Server (NTRS)

Forsythe, R. E.; King, J. L.

1979-01-01

The following technical developments are described: (1) a reliable 183 GHz subharmonic mixer, (2) a precision noise figure test setup, (3) the successful deposition of SiO2 on a noncontacting backshort, and (4) sturdier whisker points used for diode contacting.

Millimeter and Sub-millimeter High Resolution Spectroscopy: New Frontiers with ALMA

NASA Astrophysics Data System (ADS)

Ziurys, Lucy M.

2016-06-01

It is becoming increasingly clear that new laboratory data will be critical for the next decade of observations with the Atacama Large Millimeter Array (ALMA). The high spatial resolution offered by ALMA will probe new regions of molecular complexity, including the inner envelopes of evolved stars, regions dominated by UV radiation, and the densest cores of molecular clouds. New molecular lines will be discovered in the wide wavelength range covered by the ALMA bands, and high resolution, gas-phase spectroscopy are needed to provide crucial “rest frequencies.” In particular, highly accurate methods that measure millimeter and sub-millimeter rotational transitions, such as direct absorption and Fourier transform mm-wave techniques, are important, especially when coupled to exotic molecular production schemes. Recent ALMA studies of SH+ and larger organic species have already demonstrated the need for laboratory measurements. New laboratory work will likely be required for circumstellar refractory molecules, radicals and ions generated near photon-dominated regions (PDRs), and large, organic-type species. This talk will give an overview of current contributions of laboratory spectroscopy to ALMA observations, summarize relevant spectroscopic techniques, and provide input into future prospects and directions.

Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies.

PubMed

Balal, Nezah; Pinhasi, Gad A; Pinhasi, Yosef

2016-05-23

The wide band at extremely high frequencies (EHF) above 30 GHz is applicable for high resolution directive radars, resolving the lack of free frequency bands within the lower part of the electromagnetic spectrum. Utilization of ultra-wideband signals in this EHF band is of interest, since it covers a relatively large spectrum, which is free of users, resulting in better resolution in both the longitudinal and transverse dimensions. Noting that frequencies in the millimeter band are subjected to high atmospheric attenuation and dispersion effects, a study of the degradation in the accuracy and resolution is presented. The fact that solid-state millimeter and sub-millimeter radiation sources are producing low power, the method of continuous-wave wideband frequency modulation becomes the natural technique for remote sensing and detection. Millimeter wave radars are used as complementary sensors for the detection of small radar cross-section objects under bad weather conditions, when small objects cannot be seen by optical cameras and infrared detectors. Theoretical analysis for the propagation of a wide "chirped" Frequency-Modulated Continuous-Wave (FMCW) radar signal in a dielectric medium is presented. It is shown that the frequency-dependent (complex) refractivity of the atmospheric medium causes distortions in the phase of the reflected signal, introducing noticeable errors in the longitudinal distance estimations, and at some frequencies may also degrade the resolution.

Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies

PubMed Central

Balal, Nezah; Pinhasi, Gad A.; Pinhasi, Yosef

2016-01-01

The wide band at extremely high frequencies (EHF) above 30 GHz is applicable for high resolution directive radars, resolving the lack of free frequency bands within the lower part of the electromagnetic spectrum. Utilization of ultra-wideband signals in this EHF band is of interest, since it covers a relatively large spectrum, which is free of users, resulting in better resolution in both the longitudinal and transverse dimensions. Noting that frequencies in the millimeter band are subjected to high atmospheric attenuation and dispersion effects, a study of the degradation in the accuracy and resolution is presented. The fact that solid-state millimeter and sub-millimeter radiation sources are producing low power, the method of continuous-wave wideband frequency modulation becomes the natural technique for remote sensing and detection. Millimeter wave radars are used as complementary sensors for the detection of small radar cross-section objects under bad weather conditions, when small objects cannot be seen by optical cameras and infrared detectors. Theoretical analysis for the propagation of a wide “chirped” Frequency-Modulated Continuous-Wave (FMCW) radar signal in a dielectric medium is presented. It is shown that the frequency-dependent (complex) refractivity of the atmospheric medium causes distortions in the phase of the reflected signal, introducing noticeable errors in the longitudinal distance estimations, and at some frequencies may also degrade the resolution. PMID:27223286

ATS-5 millimeter wave propagation measurements

NASA Technical Reports Server (NTRS)

Ippolito, L. J.

1973-01-01

Long term experimental measurements to determine the propagation characteristics of 15 and 32 GHz earth-space links and to evaluate performance characteristics of operational millimeter wave systems are reported. The ATS 5 millimeter wave experimental link experienced attenuation and fading characteristics as a function of rainfall rate and other meteorological parameters. A method of site selection for the lowest attenuation rainfall rate improved reception tremendously.

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.

Generating millimeter-wave Bessel beam with orbital angular momentum using reflective-type metasurface inherently integrated with source

NASA Astrophysics Data System (ADS)

Shen, Yizhu; Yang, Jiawei; Meng, Hongfu; Dou, Wenbin; Hu, Sanming

2018-04-01

Metasurfaces, orbital angular momenta (OAM), and non-diffractive Bessel beams have been attracting worldwide research. Combining the benefits of these three promising techniques, this paper proposes a metasurface-based reflective-type approach to generate a first-order Bessel beam carrying OAM. To validate this approach, a millimeter-wave metasurface is analyzed, designed, fabricated, and measured. Experimental results agree well with simulation. Moreover, this reflective-type metasurface, generating a Bessel beam with OAM, is inherently integrated with a planar feeding source in the same single-layer printed circuit board. Therefore, the proposed design features low profile, low cost, easy integration with front-end active circuits, and no alignment error between the feeding source and the metasurface.

Architectural Considerations of Fiber-Radio Millimeter-Wave Wireless Access Systems

NASA Astrophysics Data System (ADS)

Kitayama, Ken-Ichi

The architecture of fiber-radio mm-wave wireless access systems critically depends upon the optical mm-wave generation and transport techniques. Four optical mm-wave generation and transport techniques: 1) optical self-heterodyning, 2) external modulation, 3) up- and downconversion, and 4) optical transceiver, will be assessed. From the technical viewpoints, their advantages and disadvantages are discussed. The economical assessment, focusing on the cost of a base station BS ( ), will suggest that the optical transceiver looks the most promising in the long run, but in the near future, however, the external modulation will be cost-effective. The experimental results of 60 GHz testbeds using the external modulation will support the conclusion.

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 for backscattering and transmission measurements are presented for both targets for the frequencies from 95.1 to 110.1 GHz.

Microwave and millimeter wave dielectric permittivity and magnetic permeability of epsilon-gallium-iron-oxide nano-powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Liu, E-mail: liu.chao@tufts.edu; Afsar, Mohammed N.; Ohkoshi, Shin-ichi

2015-05-07

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 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 of 30 GHz to 150 GHz. The ε-Ga{sub x}Fe{sub 2−x}O{sub 3} is synthesized by the sol-gel method. The particlemore » sizes are observed to be smaller than 100 nm. In this paper, in-waveguide transmission and reflection method and the free space magneto-optical approach have been employed to study these newly developed ε-Ga{sub x}Fe{sub 2−x}O{sub 3} particles in millimeter waves. These techniques enable to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the microwave and millimeter wave frequency range from single set of direct measurements. The complex dielectric permittivity and magnetic permeability 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.« less

Development of Millimeter-Wave Velocimetry and Acoustic Time-of-Flight Tomography for Measurements in Densely Loaded Gas-Solid Riser Flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fort, James A.; Pfund, David M.; Sheen, David M.

2007-04-01

The MFDRC was formed in 1998 to advance the state-of-the-art in simulating multiphase turbulent flows by developing advanced computational models for gas-solid flows that are experimentally validated over a wide range of industrially relevant conditions. The goal was to transfer the resulting validated models to interested US commercial CFD software vendors, who would then propagate the models as part of new code versions to their customers in the US chemical industry. Since the lack of detailed data sets at industrially relevant conditions is the major roadblock to developing and validating multiphase turbulence models, a significant component of the work involvedmore » flow measurements on an industrial-scale riser contributed by Westinghouse, which was subsequently installed at SNL. Model comparisons were performed against these datasets by LANL. A parallel Office of Industrial Technology (OIT) project within the consortium made similar comparisons between riser measurements and models at NETL. Measured flow quantities of interest included volume fraction, velocity, and velocity-fluctuation profiles for both gas and solid phases at various locations in the riser. Some additional techniques were required for these measurements beyond what was currently available. PNNL’s role on the project was to work with the SNL experimental team to develop and test two new measurement techniques, acoustic tomography and millimeter-wave velocimetry. Acoustic tomography is a promising technique for gas-solid flow measurements in risers and PNNL has substantial related experience in this area. PNNL is also active in developing millimeter wave imaging techniques, and this technology presents an additional approach to make desired measurements. PNNL supported the advanced diagnostics development part of this project by evaluating these techniques and then by adapting and developing the selected technology to bulk gas-solids flows and by implementing them for testing in the SNL riser testbed.« less

Development of a contrast phantom for active millimeter-wave imaging systems

NASA Astrophysics Data System (ADS)

Barber, Jeffrey; Weatherall, James C.; Brauer, Carolyn S.; Smith, Barry T.

2011-06-01

As the development of active millimeter wave imaging systems continues, it is necessary to validate materials that simulate the expected response of explosives. While physics-based models have been used to develop simulants, it is desirable to image both the explosive and simulant together in a controlled fashion in order to demonstrate success. To this end, a millimeter wave contrast phantom has been created to calibrate image grayscale while controlling the configuration of the explosive and simulant such that direct comparison of their respective returns can be performed. The physics of the phantom are described, with millimeter wave images presented to show successful development of the phantom and simulant validation at GHz frequencies.

PNNL Expert Doug McMakin Discusses Millimeter Wave Technology

ScienceCinema

McMakin, Doug

2018-02-13

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.

Reflectometric measurement of plasma imaging and applications

NASA Astrophysics Data System (ADS)

Mase, A.; Ito, N.; Oda, M.; Komada, Y.; Nagae, D.; Zhang, D.; Kogi, Y.; Tobimatsu, S.; Maruyama, T.; Shimazu, H.; Sakata, E.; Sakai, F.; Kuwahara, D.; Yoshinaga, T.; Tokuzawa, T.; Nagayama, Y.; Kawahata, K.; Yamaguchi, S.; Tsuji-Iio, S.; Domier, C. W.; Luhmann, N. C., Jr.; Park, H. K.; Yun, G.; Lee, W.; Padhi, S.; Kim, K. W.

2012-01-01

Progress in microwave and millimeter-wave technologies has made possible advanced diagnostics for application to various fields, such as, plasma diagnostics, radio astronomy, alien substance detection, airborne and spaceborne imaging radars called as synthetic aperture radars, living body measurements. Transmission, reflection, scattering, and radiation processes of electromagnetic waves are utilized as diagnostic tools. In this report we focus on the reflectometric measurements and applications to biological signals (vital signal detection and breast cancer detection) as well as plasma diagnostics, specifically by use of imaging technique and ultra-wideband radar technique.

Microwave Remote Sensing of Falling Snow

NASA Technical Reports Server (NTRS)

Kim, Min-Jeong; Wang, J. R.; Meneghini, R.; Johnson, B.; Tanelli, S.; Roman-Nieves, J. I.; Sekelsky, S. M.; Skofronick-Jackson, G.

2005-01-01

This study analyzes passive and active microwave measurements during the 2003 Wakasa Bay field experiment for understanding of the electromagnetic characteristics of frozen hydrometeors at millimeter-wave frequencies. Based on these understandings, parameterizations of the electromagnetic scattering properties of snow at millimeter-wave frequencies are developed and applied to the hydrometeor profiles obtained by airborne radar measurements. Calculated brightness temperatures and radar reflectivity are compared with the millimeter-wave measurements.

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.

Wide-field-of-view millimeter-wave telescope design with ultra-low cross-polarization

NASA Astrophysics Data System (ADS)

Bernacki, Bruce E.; Kelly, James F.; Sheen, David; Hatchell, Brian; Valdez, Patrick; Tedeschi, Jonathan; Hall, Thomas; McMakin, Douglas

2012-06-01

As millimeter-wave arrays become available, off-axis imaging performance of the fore optics increases in importance due to the relatively large physical extent of the arrays. Typically, simple optical telescope designs are adapted to millimeter-wave imaging but single-mirror spherical or classic conic designs cannot deliver adequate image quality except near the optical axis. Since millimeter-wave designs are quasi-optical, optical ray tracing and commercial design software can be used to optimize designs to improve off-axis imaging as well as minimize cross-polarization. Methods that obey the Dragone-Mizuguchi condition for the design of reflective millimeter-wave telescopes with low cross-polarization also provide additional degrees of freedom that offer larger fields of view than possible with single-reflector designs. Dragone's graphical design method does not lend itself readily to computer-based optical design approaches, but subsequent authors expanded on Dragone's geometric design approach with analytic expressions that describe the location, shape, off-axis height and tilt of the telescope elements that satisfy Dragone's design rules and can be used as a first-order design for subsequent computer-based design and optimization. We investigate two design variants that obey the Dragone-Mizuguchi conditions that exhibit ultra-low cross-polarization and a large diffraction-limited field of view well suited to millimeter-wave imaging arrays.

Millimeter wave micro-CPW integrated antenna

NASA Astrophysics Data System (ADS)

Tzuang, Ching-Kuang C.; Lin, Ching-Chyuan

1996-12-01

This paper presents the latest result of applying the microstrip's leaky mode for a millimeter-wave active integrated antenna design. In contrast to the use of the first higher-order leaky mode, the second higher-order leaky mode, the second higher-order leaky mode of even symmetry is employed in the new approach, which allows larger dimension for leaky-wave antenna design and thereby reduces its performance sensitivity to the photolithographic tolerance. The new active integrated antenna operating at frequency about 34 GHz comprises of a microstrip and a coplanar waveguide stacked on top of each other, named as the millimeter wave micro-CPW integrated antenna. The feed is through the CPW that would be connected to the active uniplanar millimeter-wave (M)MIC's. Our experimental and theoretical investigations on the new integrated antenna show good input matching characteristics for such a highly directed leaky-wave antenna with the first-pass success.

Dual-surface dielectric depth detector for holographic millimeter-wave security scanners

NASA Astrophysics Data System (ADS)

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

2009-05-01

The Transportation Security Administration (TSA) is presently deploying millimeter-wave whole body scanners at over 20 airports in the United States. Threats that may be concealed on a person are displayed to the security operator of this scanner. "Passenger privacy is ensured through the anonymity of the image. The officer attending the passenger cannot view the image, and the officer viewing the image is remotely located and cannot see the passenger. Additionally, the image cannot be stored, transmitted or printed and is deleted immediately after being viewed. Finally, the facial area of the image has been blurred to further ensure privacy." Pacific Northwest National Laboratory (PNNL) originated research into this novel security technology which has been independently commercialized by L-3 Communications, SafeView, Inc. PNNL continues to perform fundamental research into improved software techniques which are applicable to the field of holographic security screening technology. This includes performing significant research to remove human features from the imagery. Both physical and software imaging techniques have been employed. The physical imaging techniques include polarization diversity illumination and reception, dual frequency implementation, and high frequency imaging at 100 GHz. This paper will focus on a software privacy technique using a dual surface dielectric depth detector method.

Photonic Materials and Devices for RF (mmW) Sensing and Imaging

DTIC Science & Technology

2012-12-31

wave encoding thereby eliminating the need for bulky LO distribution cables. Also, optical processing techniques can be utilized to provide simple... optical powers, can be close to unity and low -noise photodetectors make the detection of exceedingly low power millimeter-waves practical. In... optically -filtering the modulated signal to pass only a single sideband and detecting the resultant optical signal with a low -noise photodetector we have

A silicon technology for millimeter-wave monolithic circuits

NASA Astrophysics Data System (ADS)

Stabile, P. J.; Rosen, A.

1984-12-01

A silicon millimeter-wave integrated-circuit (SIMMWIC) technology that includes high-energy ion implantation and pulsed-laser annealing, secondary ion mass spectrometry (SIMS) profile diagnostics, and novel wafer thinning has been developed. This technology has been applied to a SIMMWIC single-pole single-throw (SPST) switch and to IMPATT and p-i-n diode fabrication schemes. Thus, the SIMMWIC technology is a proven base for monolithic millimeter-wave sources and control circuit applications.

Full colorless transmission of millimeter-wave band gigabit data over WDM-PON using sideband routing

NASA Astrophysics Data System (ADS)

Won, Yong-Yuk; Kim, Hyun-Seung; Son, Yong-Hwan; Han, Sang-Kook

2011-12-01

A new wavelength division multiplexed-radio over fiber (WDM-RoF) access network scheme supporting the simultaneous transmission of a 1.25-Gb/s wired data as well as a 1.25-Gb/s wireless data is proposed in this paper. An optical carrier suppression effect and sideband routing using the multiplexing of arrayed waveguide grating (AWG) with 50-GHz channel spacing are utilized to generate a millimeter wave band carrier. These techniques make the proposed architecture transmit both a wired data and a wireless one at the same time. A reflective semiconductor optical amplifier (RSOA) is employed at both central office and base station so that this architecture is operated colorlessly. Error free transmissions (BER of 10-9) of both downlink and uplink are achieved simultaneously.

Millimeter-Wave Time Resolved Studies of the Formation and Decay of CO^+

NASA Astrophysics Data System (ADS)

Oesterling, Lee; Herbst, Eric; de Lucia, Frank

1998-04-01

Since the rate constants for ion-molecule interactions are typically much larger than neutral-neutral interactions, understanding ion-molecule interactions is essential to interpreting radio astronomical spectra from interstellar clouds and modeling the processes which lead to the formation of stars in these regions. We have developed a cell which allows us to study ion-molecule interactions in gases at low temperatures and pressures by using an electron gun technique to create ions. By centering our millimeter-wave source on a rotational resonance and gating the electron beam on and off, we are able to study the time-dependent rotational state distribution of the ion during its formation and decay, and so learn about excitation and relaxation processes as functions of temperature, pressure, electron beam energy, and electron beam current.

A technique to measure the thermal diffusivity of high Tc superconductors

NASA Technical Reports Server (NTRS)

Powers, Charles E.

1991-01-01

High T(sub c) superconducting electrical current leads and ground straps will be used in cryogenic coolers in future NASA Goddard Space Flight Center missions. These superconducting samples are long, thin leads with a typical diameter of two millimeters. A longitudinal method is developed to measure the thermal diffusivity of candidate materials for this application. This technique uses a peltier junction to supply an oscillatory heat wave into one end of a sample and will use low mass thermocouples to follow the heat wave along the sample. The thermal diffusivity is calculated using both the exponential decay of the heat wave and the phase shift to the wave. Measurements are performed in a cryostat between 10 K and room temperature.

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.

Critical object recognition in millimeter-wave images with robustness to rotation and scale.

PubMed

Mohammadzade, Hoda; Ghojogh, Benyamin; Faezi, Sina; Shabany, Mahdi

2017-06-01

Locating critical objects is crucial in various security applications and industries. For example, in security applications, such as in airports, these objects might be hidden or covered under shields or secret sheaths. Millimeter-wave images can be utilized to discover and recognize the critical objects out of the hidden cases without any health risk due to their non-ionizing features. However, millimeter-wave images usually have waves in and around the detected objects, making object recognition difficult. Thus, regular image processing and classification methods cannot be used for these images and additional pre-processings and classification methods should be introduced. This paper proposes a novel pre-processing method for canceling rotation and scale using principal component analysis. In addition, a two-layer classification method is introduced and utilized for recognition. Moreover, a large dataset of millimeter-wave images is collected and created for experiments. Experimental results show that a typical classification method such as support vector machines can recognize 45.5% of a type of critical objects at 34.2% false alarm rate (FAR), which is a drastically poor recognition. The same method within the proposed recognition framework achieves 92.9% recognition rate at 0.43% FAR, which indicates a highly significant improvement. The significant contribution of this work is to introduce a new method for analyzing millimeter-wave images based on machine vision and learning approaches, which is not yet widely noted in the field of millimeter-wave image analysis.

Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1987-01-01

Laboratory measurements were conducted to evaluate properties of atmospheric gases under simulated conditions for the outer planets. A significant addition to this effort was the capability to make such measurements at millimeter wavelengths. Measurements should soon be completed on the millimeter wave absorption from ammonia under Jovian conditions. Also studied will be the feasibility of measuring the microwave and millimeter wave properties of phosphine (PH3) under simulated Jovian conditions. Further analysis and application of the laboratory results to microwave and millimeter wave absorption data for the outer planet, such as Voyager Radio Occultation experiments, will be pursued.

Wide-Field-of-View Millimeter-Wave Telescope Design with Ultra-Low Cross-Polarization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernacki, Bruce E.; Kelly, James F.; Sheen, David M.

2012-05-01

As millimeter-wave arrays become available, off-axis imaging performance of the fore optics increases in importance due to the relatively large physical extent of the arrays. Typically, simple optical telescope designs are adapted to millimeter-wave imaging but single-mirror spherical or classic conic designs cannot deliver adequate image quality except near the optical axis. Since most millimeter-wave designs are quasi-optical, optical ray tracing and commercial design software can be used to optimize designs to improve off-axis imaging as well as minimize cross-polarization. Methods that obey the Dragone-Mizuguchi condition for the design of reflective millimeter-wave telescopes with low cross-polarization also provide additional degreesmore » of freedom that offer larger fields of view than possible with single-reflector designs. Dragone’s graphical design method does not lend itself readily to computer-based optical design approaches, but subsequent authors expanded on Dragone’s geometric design approach with analytic expressions that describe the location, shape, off-axis height and tilt of the telescope elements that satisfy Dragone’s design rules and can be used as a first-order design for subsequent computer-based design and optimization. We investigate two design variants that obey the Dragone-Mizuguchi conditions that exhibit ultra-low polarization crosstalk and a large diffraction-limited field of view well suited to millimeter-wave imaging arrays.« less

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.

Microwave, Millimeter, Submillimeter, and Far Infrared Spectral Databases

NASA Technical Reports Server (NTRS)

Pearson, J. C.; Pickett, H. M.; Drouin, B. J.; Chen, P.; Cohen, E. A.

2002-01-01

The spectrum of most known astrophysical molecules is derived from transitions between a few hundred to a few hundred thousand energy levels populated at room temperature. In the microwave and millimeter wave regions. spectroscopy is almost always performed with traditional microwave techniques. In the submillimeter and far infrared microwave technique becomes progressively more technologically challenging and infrared techniques become more widely employed as the wavelength gets shorter. Infrared techniques are typically one to two orders of magnitude less precise but they do generate all the strong features in the spectrum. With microwave technique, it is generally impossible and rarely necessary to measure every single transition of a molecular species, so careful fitting of quantum mechanical Hamiltonians to the transitions measured are required to produce the complete spectral picture of the molecule required by astronomers. The fitting process produces the most precise data possible and is required in the interpret heterodyne observations. The drawback of traditional microwave technique is that precise knowledge of the band origins of low lying excited states is rarely gained. The fitting of data interpolates well for the range of quantum numbers where there is laboratory data, but extrapolation is almost never precise. The majority of high resolution spectroscopic data is millimeter or longer in wavelength and a very limited number of molecules have ever been studied with microwave techniques at wavelengths shorter than 0.3 millimeters. The situation with infrared technique is similarly dire in the submillimeter and far infrared because the black body sources used are competing with a very significant thermal background making the signal to noise poor. Regardless of the technique used the data must be archived in a way useful for the interpretation of observations.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 carriedmore » 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.« less

Ultra-Wideband Millimeter-Wave Dielectric Characteristics of Freshly Excised Normal and Malignant Human Skin Tissues.

PubMed

Mirbeik-Sabzevari, Amir; Ashinoff, Robin; Tavassolian, Negar

2018-06-01

Millimeter waves have recently gained attention for the evaluation of skin lesions and the detection of skin tumors. Such evaluations heavily rely on the dielectric contrasts existing between normal and malignant skin tissues at millimeter-wave frequencies. However, current studies on the dielectric properties of normal and diseased skin tissues at these frequencies are limited and inconsistent. In this study, a comprehensive dielectric spectroscopy study is conducted for the first time to characterize the ultra-wideband dielectric properties of freshly excised normal and malignant skin tissues obtained from skin cancer patients having undergone Mohs micrographic surgeries at Hackensack University Medical Center. Measurements are conducted using a precision slim-form open-ended coaxial probe in conjunction with a millimeter-wave vector network analyzer over the frequency range of 0.5-50 GHz. A one-pole Cole-Cole model is fitted to the complex permittivity dataset of each sample. Statistically considerable contrasts are observed between the dielectric properties of malignant and normal skin tissues over the ultra-wideband millimeter-wave frequency range considered.

Effects of Different Types of Burn Wounds and its Dressings on Millimeter-Wave Images

NASA Astrophysics Data System (ADS)

Daniel, Oppelt; Patrick, Korf; Julian, Adametz; Jannis, Groh; Martin, Vossiek; Kristina, Zhuravleva; Ole, Goertz

2018-03-01

Millimeter-wave imaging is a promising technology for diagnosing skin burns, that may make it easier to assess and determine the burn depth in the near future. However, up to now, it has not yet been brought to clinical use due to the lack of clinical trails on patients and a millimeter-wave-aided classification of skin burns. In this paper, in a preliminary step, ex-vivo burned porcine skin is utilized to visualize and quantify skin that has been burned in different ways, and to access its effect on millimeter-wave images. For the first time, a 24 hour study of in-vivo human skin visualizes the effect of wound dressings using a fast imaging system operating at frequencies from 70 to 80 GHz. For validation, the effective relative permittivity of the skin and the dressings are measured using a open-ended coaxial probe. An analytical model is applied to calculate the reflection coefficient which are compared to the intensity of the millimeter-wave images to validate the model.

Semiconductor millimeter wavelength electronics

NASA Astrophysics Data System (ADS)

Rosenbaum, F. J.

1985-12-01

This final report summarizes the results of research carried out on topics in millimeter wavelength semiconductor electronics under an ONR Selected Research Opportunity program. Study areas included III-V compound semiconductor growth and characterization, microwave and millimeter wave device modeling, fabrication and testing, and the development of new device concepts. A new millimeter wave mixer and detector, the Gap diode was invented. Topics reported on include ballistic transport, Zener oscillations, impurities in GaAs, electron velocity-electric field calculation and measurements, etc., calculations.

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.

Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

NASA Technical Reports Server (NTRS)

Gasiewski, Albin J.; Adelberg, L. K.; Kunkee, D. B.; Jackson, D. M.

1993-01-01

Activities within the period from July 1, 1992 through December 31, 1992 by Georgia Tech researchers in millimeter and submillimeter wavelength tropospheric remote sensing have been centered around the calibration of the Millimeter-wave Imaging Radiometer (MIR), preliminary flight data analysis, and preparation for TOGA/COARE. The MIR instrument is a joint project between NASA/GSFC and Georgia Tech. In the current configuration, the MIR has channels at 90, 150, 183(+/-1,3,7), and 220 GHz. Provisions for three additional channels at 325(+/-1,3) and 8 GHz have been made, and a 325-GHz receiver is currently being built by the ZAX Millimeter Wave Corporation for use in the MIR. Past Georgia Tech contributions to the MIR and its related scientific uses have included basic system design studies, performance analyses, and circuit and radiometric load design, in-flight software, and post-flight data display software. The combination of the above millimeter wave and submillimeter wave channels aboard a single well-calibrated instrument will provide unique radiometric data for radiative transfer and cloud and water vapor retrieval studies. A paper by the PI discussing the potential benefits of passive millimeter and submillimeter wave observations for cloud, water vapor and precipitation measurements has recently been published, and is included as an appendix.

Millimeter wavelength observations of solar flares for Max 1991

NASA Technical Reports Server (NTRS)

Kundu, M. R.; Gopalswamy, N.; Nitta, N.; Schmahl, E. J.; White, S. M.; Welch, W. J.

1988-01-01

The Hat Creek millimeter-wave interferometer (to be known as the Berkeley-Illinois-Maryland Array, BIMA) is being upgraded. The improved array will become available during the coming solar maximum, and will have guaranteed time for solar observing. The Hat Creek millimeter-wave interferometer is described along with the improvements. The scientific objectives are briefly discussed.

High-Resolution Millimeter Wave Detection of Vertical Cracks in the Space Shuttle External Tank (ET) Spray-on-Foam Insulation (SOFI)

NASA Technical Reports Server (NTRS)

Kharkovsky, S.; Zoughi, R.; Hepburn, Frank L.

2006-01-01

Space Shuttle Columbia's catastrophic failure has been attributed to a piece of spray-on-foam insulation (SOFI) that was dislodged from the external tank (ET) and struck the leading edge of the left wing. A piece of SOFI was also dislodged in the Space Shuttle Discovery's flight in 2005 and recently a crack was detected in its ET foam prior to its successful launch. Millimeter wave nondestructive testing methods have been considered as potential effective inspection tools for evaluating the integrity of the SOFI. Recently, in a specific investigation into the potential of these methods for detecting vertical cracks in SOFI was explored using a focused millimeter wave reflectometer at 150 GHz. The results showed the capability of these methods for detecting tight vertical cracks (also as a function of crack opening dimension) in exposed SOFI panels and while covered by a piece of SOFI ramp simulating a more realistic and challenging situation. Some crack-like anomalies were also detected in a blind SOFI panel. This paper presents the background for these techniques as well as representative images of the vertical crack in the SOFI panel, crack-like anomalies in the blind panel and a discussion of the practical attributes of these inspection methods.

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

Application of temperature-dependent fluorescent dyes to the measurement of millimeter wave absorption in water applied to biomedical experiments.

PubMed

Kuzkova, Nataliia; Popenko, Oleksandr; Yakunov, Andrey

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.

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.

Chirped-Pulse Millimeter-Wave Spectroscopy of Rydberg-Rydberg Transitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prozument, Kirill; Colombo, Anthony P.; Zhou Yan

2011-09-30

Transitions between Rydberg states of Ca atoms, in a pulsed, supersonic atomic beam, are directly detected by chirped-pulse millimeter-wave spectroscopy. Broadband, high-resolution spectra with accurate relative intensities are recorded instantly. Free induction decay (FID) of atoms, polarized by the chirped pulse, at their Rydberg-Rydberg transition frequencies, is heterodyne detected, averaged in the time domain, and Fourier transformed into the frequency domain. Millimeter-wave transient nutations are observed, and the possibility of FID evolving to superradiance is discussed.

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-type barium micro- and nano-ferrite. A new fabrication process using ferrite composite is proposed to integrate the Y-junction circulator into the semiconductor substrate. Theoretical design of a high gain Traveling Wave Tube (TWT) amplifier using a metamaterial (MTM) structure and cold-test of the MTM structure are also included in this dissertation. An SWS working around 6 GHz below the X-band waveguide TE10 cutoff frequency is fabricated.

A Tri-Band Frequency Selective Surface (FSS) to Diplex Widely Separated Bands for Millimeter Wave Remote Sensing

NASA Astrophysics Data System (ADS)

Poojali, Jayaprakash; Ray, Shaumik; Pesala, Bala; Chitti, Krishnamurthy V.; Arunachalam, Kavitha

2016-10-01

A substrate-backed frequency selective surface (FSS) is presented for diplexing the widely separated frequency spectrum centered at 55, 89, and 183 GHz with varying bandwidth for spatial separation in the quasi-optical feed network of the millimeter wave sounder. A unit cell composed of a crossed dipole integrated with a circular ring and loaded inside a square ring is optimized for tri-band frequency response with transmission window at 89 GHz and rejection windows at 55 and 183 GHz. The reflection and transmission losses predicted for the optimized unit cell (728 μm × 728 μm) composed of dissimilar resonant shapes is less than 0.5 dB for transverse electric (TE) and transverse magnetic (TM) polarizations and wide angle of incidence (0°-45°). The FSS is fabricated on a 175-μm-thick quartz substrate using microfabrication techniques. The transmission characteristics measured with continuous wave (CW) terahertz transmit receive system are in good agreement with the numerical simulations.

Concentric Parallel Combining Balun for Millimeter-Wave Power Amplifier in Low-Power CMOS with High-Power Density

NASA Astrophysics Data System (ADS)

Han, Jiang-An; Kong, Zhi-Hui; Ma, Kaixue; Yeo, Kiat Seng; Lim, Wei Meng

2016-11-01

This paper presents a novel balun for a millimeter-wave power amplifier (PA) design to achieve high-power density in a 65-nm low-power (LP) CMOS process. By using a concentric winding technique, the proposed parallel combining balun with compact size accomplishes power combining and unbalance-balance conversion concurrently. For calculating its power combination efficiency in the condition of various amplitude and phase wave components, a method basing on S-parameters is derived. Based on the proposed parallel combining balun, a fabricated 60-GHz industrial, scientific, and medical (ISM) band PA with single-ended I/O achieves an 18.9-dB gain and an 8.8-dBm output power at 1-dB compression and 14.3-dBm saturated output power ( P sat) at 62 GHz. This PA occupying only a 0.10-mm2 core area has demonstrated a high-power density of 269.15 mW/mm2 in 65 nm LP CMOS.

Performance Investigation of Millimeter Wave Generation Reliant on Stimulated Brillouin Scattering

NASA Astrophysics Data System (ADS)

Tickoo, Sheetal; Gupta, Amit

2018-04-01

In this work, photonic method of generating the millimeter waves has been done based on Brillouin scattering effect in optical fiber. Here different approaches are proposed to get maximum frequency shift in mm-wave region using only pumps, radio signals with Mach-Zehnder modulator. Moreover for generated signal validation, signals modulated and send to both wired and wireless medium in optical domain. It is observed that maximum shift of 300 GHz is realized using 60 GHz input sine wave. Basically a frequency doubler is proposed which double shift of input frequency and provide better SNR. For the future generation network system, the generation of millimeter waves makes them well reliable for the transmission of the data.

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

NASA Technical Reports Server (NTRS)

Ippolito, L. J.

1976-01-01

Studies at 11 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 using the Applications Technology Satellite-6(ATS-6). 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 were presented. The first section describes the experiment objectives, flight hardware, and modes of operation. The remaining six sections present papers prepared by the major participating organizations in the experiment. The papers present a comprehensive summary of the significant results of the initial 11 months of ATS-6 experiment measurements and related radiometric, radar, and radio-meteorology studies.

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.

Application of the planar-scanning technique to the near-field dosimetry of millimeter-wave radiators.

PubMed

Zhao, Jianxun; Lu, Hongmin; Deng, Jun

2015-02-01

The planar-scanning technique was applied to the experimental measurement of the electric field and power flux density (PFD) in the exposure area close to the millimeter-wave (MMW) radiator. In the near-field region, the field and PFD were calculated from the plane-wave spectrum of the field sampled on a scan plane far from the radiator. The measurement resolution was improved by reducing the spatial interval between the field samples to a fraction of half the wavelength and implementing multiple iterations of the fast Fourier transform. With the reference to the results from the numerical calculation, an experimental evaluation of the planar-scanning measurement was made for a 50 GHz radiator. Placing the probe 1 to 3 wavelengths from the aperture of the radiator, the direct measurement gave the near-field data with significant differences from the numerical results. The planar-scanning measurement placed the probe 9 wavelengths away from the aperture and effectively reduced the maximum and averaged differences in the near-field data by 70.6% and 65.5%, respectively. Applied to the dosimetry of an open-ended waveguide and a choke ring antenna for 60 GHz exposure, the technique proved useful to the measurement of the PFD in the near-field exposure area of MMW radiators. © 2015 Wiley Periodicals, Inc.

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.

Millimeter wave propagation measurements using the ATS 5 satellite

NASA Technical Reports Server (NTRS)

Ippolito, L. J.

1972-01-01

The ATS 5 millimeter wave propagation experiment determines long- and short-term attenuation statistics of operational millimeter wavelength earthspace links as functions of defined meteorological conditions. A preliminary analysis of results with 15 GHz downlink and 32 GHz uplink frequency bands indicates that both frequency bands exhibit an excellent potential for utilization in reliable high data rate earth-space communications systems.

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.

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.

Investigation of Microwave Monolithic Integrated Circuit (MMIC) Non-Reciprocal Millimeterwave Components

DTIC Science & Technology

1991-09-01

nickel zinc ferrite films and (2) sputtering of barium hexaferrites with C-axis oriented normally to the film plane. The SSP tech- nique potential for...M-Wave, Components, Ferrites, Films , Yig, Nickel, Zinc , Hexagonal, R96E Measurements, Frequency, Magnetic, Barium Ferrite 17. SECURITY CLASSIFICATION...techniques to integrate millimeter-wave ferrite devices with GaAs VI&Cs. APPROACH Our approach was to deposit ferrite thin films on GaAs sub- strates in a

Millimeter wave radar for automobile crash avoidance systems

NASA Astrophysics Data System (ADS)

Huguenin, G. Richard

1994-08-01

Low cost, millimeter wave, forward looking radar sensors for applications in Autonomous Collision Warning and Autonomous Intelligent Cruise Control systems will be described. These safety related systems promise the largest payoff in preventing highway crashes.

High power broadband millimeter wave TWTs

NASA Astrophysics Data System (ADS)

James, Bill G.

1999-05-01

In the early 1980's the requirement for high power broadband millimeter wave sources encouraged the development of microwave vacuum device amplifiers for radar and communication systems. Many government funded programs were implemented for the development of high power broadband millimeter wave amplifiers that would meet the needs of the high power community. The tube design capable of meeting these goals was the slow wave coupled cavity traveling wave device, which had a proven technology base at the lower frequencies (X Band). However scaling this technology to the millimeter frequencies had severe shortcomings in both thermal and manufacturing design. These shortcomings were overcome with the development of the Ladder Circuit technology. In conjunction with the circuit development high power electron beam systems had to be developed for the generation of high rf powers. These beam systems had to be capable of many megawatts of beam power density and high current densities. The cathode technology required to be capable of operating at current densities of 10 amperes per square centimeter at long pulse lengths and high duty cycle. Since the introduction of the Ladder Circuit technology a number of high power broadband millimeter wave amplifiers have been developed using this technology, and have been deployed in operating radar and communication systems. Broadband millimeter wave sources have been manufactured in the frequency range from 27 GHz to 100 GHz with power levels ranging from 100 watts to 50 kilowatts. Today the power levels achieved by these devices are nearing the limits of this technology; therefore to gain a significant increase in power at the millimeter wave frequencies other technologies will have to be considered particularly fast wave devices. This paper will briefly review the ladder circuit technology and present the designs of a number of broadband high power devices developed at Ka and W band. The discussion will include the beam systems employed in these devices which are the highest power density linear beams generated to date. In conclusion the limits of the power generating capability of this technology will be presented.

High Power Broadband Millimeter Wave TWTs

NASA Astrophysics Data System (ADS)

James, Bill G.

1998-04-01

In the early 1980's the requirement for high power broadband millimeter wave sources encouraged the development of microwave vacuum device amplifiers for radar and communication systems. Many government funded programs were implemented for the development of high power broadband millimeter wave amplifiers that would meet the needs of the high power community. The tube design capable of meeting these goals was the slow wave coupled cavity traveling wave device, which had a proven technology base at the lower frequencies (X Band). However scaling this technology to the millimeter frequencies had severe shortcomings in both thermal and manufacturing design. These shortcomings were overcome with the development of the Ladder Circuit technology. In conjunction with the circuit development high power electron beam systems had to be developed for the generation of high rf powers. These beam systems had to be capable of many megawatts of beam power density and high current densities. The cathode technology required to be capable of operating at current densities of 10 amperes per square centimeter at long pulse lengths and high duty cycle. Since the introduction of the Ladder Circuit technology a number of high power broadband millimeter wave amplifiers have been developed and deployed in operating radar and communication systems. Broadband millimeter wave sources have been manufactured in the frequency range from 27 GHz to 100 GHz with power levels ranging from 100 watts CW to 10 kilowatts Peak at W band over a 2 GHz bandwidth. Also a 50 kW peak power and 10 kW average power device at Ka band with 2 GHz bandwidth has been developed. Today the power levels achieved by these devices are nearing the limits of this technology; therefore to gain a significant increase in power at the millimeter wave frequencies, other technologies will have to be considered, particularly fast wave devices. This paper will briefly review the ladder circuit technology and present the designs of a number of broadband high power devices developed at Ka and W band. The discussion will include the beam systems employed in these devices which are the highest power density linear beams generated to date. In conclusion the limits of the power generating capability of this technology will be presented.

Demonstration of a Sub-Millimeter Wave Integrated Circuit (S-MMIC) using InP HEMT with a 35-nm Gate

NASA Technical Reports Server (NTRS)

Deal, W. R.; Din, S.; Padilla, J.; Radisic, V.; Mei, G.; Yoshida, W.; Liu, P. S.; Uyeda, J.; Barsky, M.; Gaier, T.;

Producibility consideration for millimeter-wave transceivers

NASA Astrophysics Data System (ADS)

Seashore, Charles R.

1995-10-01

Considerable progress has been made in the development and demonstration of millimeter wave MMIC technology up to frequencies approaching 100 GHz. The recently completed multiyear, ARPA-sponsored, MIMIC program provided a considerable amount of funding and government-contractor team energy to advance the state-of-art with a number of important GaAs-based transceiver building blocks. Unfortuanely, producibility of millimeter wave MMIC transceiver modules has not been similarly addressed to provide a truly low cost, marketable product. This paper considers the module producibility problem and its various technological implications.

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.

International Conference on Infrared and Millimeter Waves, 18th, Univ. of Essex, Colchester, United Kingdom, Sept. 6-10, 1993, Conference Digest

NASA Astrophysics Data System (ADS)

Birch, James R.; Parker, Terence J.

Papers presented in these proceedings are grouped under the topics of FEL, detectors and sources, gas lasers, spectroscopy, windows for high-power applications, scattering, plasma diagnostics, waveguides, gyrotron, quasi-optical components, biological effects of IR and millimeter waves, and astronomical and atmospheric systems. Particular attention is given to the ENEA compact millimeter wave FEL, excitonic detectors of IR and submm waves, identification of submm CD2O lines, a two-frequency quasi-optical radiospectrometer for substance investigations, the effect of window tolerances on gyrotron performance, and analysis of scattering of the open resonator field from the cavity-backed aperture. Other papers are on submm laser interferometer-polarimeter for plasma diagnostics, the characteristics of the closed circular groove guide, a kW sixth-harmonic gyrofrequency multiplier, rugged FIR bandpass filters, millimeter waves and quantum medicines, and a horizontal atmospheric temperature sounder based on the 60-GHz oxygen absorptions.

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.

Design of a Millimeter-Wave Concentrator for Beam Reception in High-Power Wireless Power Transfer

NASA Astrophysics Data System (ADS)

Fukunari, Masafumi; Wongsuryrat, Nat; Yamaguchi, Toshikazu; Nakamura, Yusuke; Komurasaki, Kimiya; Koizumi, Hiroyuki

2017-02-01

This study examined the performance of a developed taper-tube concentrator for 94-GHz millimeter-wave beam reception during wireless power transfer. The received energy is converted into kinetic energy of a working gas in the tube to drive an engine or thruster. The concentrator, which is assumed to have mirror reflection of millimeter waves in it, is designed to be shorter than conventional tapered waveguides of millimeter waves. A dimensionless design law of a concentrator is proposed based on geometric optics theory. Because the applicability of geometric optics theory is unclear, the ratio of its bore diameter to its wavelength was set as small compared to those in other possible applications. Then, the discrepancy between the designed and measured power reception was examined. Results show that the maximum discrepancy was as low as 7 % for the bore-to-wavelength ratio of 20 at the narrow end of the concentrator.

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.

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.

Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

NASA Technical Reports Server (NTRS)

Gasiewski, A. J.; Adelberg, L. K.; Kunkee, D. B.; Jackson, D. M.

1993-01-01

Progress by investigators at the Georgia Institute of Technology in the development of techniques for passive microwave retrieval of water vapor, cloud, and precipitation parameters using millimeter- and sub-millimeter wavelength channels is reviewed. Channels of particular interest are in the tropospheric transmission windows at 90, 166, 220, 340, and 410 GHz and centered around the water vapor lines at 183 and 325 GHz. Collectively, these channels have potential application in high-resolution mapping (e.g., from geosynchronous orbit), remote sensing of cloud and precipitation parameters, and retrieval of water vapor profiles. During the period from 1 Jan. 1993 through 30 Jun. 1993 the Millimeter-wave Imaging Radiometer (MIR) completed data flights during a two-month long deployment in conjunction with TOGA/COARE. Coincident data was collected from several other ground-based, airborne, and satellite sensors, including the NASA/MSFC AMPR, MIT MTS, DMSP SSM/T-2 satellite, collocated radiosondes, ground- and aircraft-based radiometers and cloud lidars, airborne infrared imagers, solar flux probes, and airborne cloud particle sampling probes.

Characteristics of enhanced-mode AlGaN/GaN MIS HEMTs for millimeter wave applications

NASA Astrophysics Data System (ADS)

Lee, Jong-Min; Ahn, Ho-Kyun; Jung, Hyun-Wook; Shin, Min Jeong; Lim, Jong-Won

2017-09-01

In this paper, an enhanced-mode (E-mode) AlGaN/GaN high electron mobility transistor (HEMT) was developed by using 4-inch GaN HEMT process. We designed and fabricated Emode HEMTs and characterized device performance. To estimate the possibility of application for millimeter wave applications, we focused on the high frequency performance and power characteristics. To shift the threshold voltage of HEMTs we applied the Al2O3 insulator to the gate structure and adopted the gate recess technique. To increase the frequency performance the e-beam lithography technique was used to define the 0.15 um gate length. To evaluate the dc and high frequency performance, electrical characterization was performed. The threshold voltage was measured to be positive value by linear extrapolation from the transfer curve. The device leakage current is comparable to that of the depletion mode device. The current gain cut-off frequency and the maximum oscillation frequency of the E-mode device with a total gate width of 150 um were 55 GHz and 168 GHz, respectively. To confirm the power performance for mm-wave applications the load-pull test was performed. The measured power density of 2.32 W/mm was achieved at frequencies of 28 and 30 GHz.

Millimeter-Wave Spectroscopy for Analytical Chemistry: Thermal Evolution of Low Volatility Impurities and Detection with a Fourier Transform Molecular Rotational Resonance Spectrometer (tev Ft-Mrr

NASA Astrophysics Data System (ADS)

Harris, Brent; Fields, Shelby S.; Neill, Justin L.; Pulliam, Robin; Muckle, Matt; Pate, Brooks

2016-06-01

Recent advances in Fourier transform millimeter-wave spectroscopy techniques have renewed the application reach of molecular rotational spectroscopy for analytical chemistry. We present a sampling method for sub ppm analysis of low volatility impurities by thermal evolution from solid powders using a millimeter-wave Fourier transform molecular rotational resonance (FT-MRR) spectrometer for detection. This application of FT-MRR is relevant to the manufacturing of safe oral pharmaceuticals. Low volatility impurities can be challenging to detect at 1 ppm levels with chromatographic techniques. One such example of a potentially mutagenic impurity is acetamide (v.p. 1 Torr at 40 C, m.p. 80 C). We measured the pure reference spectrum of acetamide by flowing the sublimated vapor pressure of acetamide crystals through the FT-MRR spectrometer. The spectrometer lower detection level (LDL) for a broadband (> 20 GHz, 10 min.) spectrum is 300 nTorr, 30 pmol, or 2 ng. For a 50 mg powder, perfect sample transfer efficiency can yield a w/w % detection limit of 35 ppb. We extended the sampling method for the acetamide reference measurement to an acetaminophen sample spiked with 5000 ppm acetamide in order to test the sample transfer efficiency when liberated from an pharmaceutical powder. A spectral reference matching algorithm detected the presence of several impurities including acetaldehyde, acetic acid, and acetonitrile that evolved at the melting point of acetaminophen, demonstrating the capability of FT-MRR for identification without a routine chemical standard. The method detection limit (MDL) without further development is less than 10 ppm w/w %. Resolved FT-MRR mixture spectra will be presented with a description of sampling methods.

Millimeter-wave imaging diagnostics systems on the EAST tokamak (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Y. L.; Xie, J. L., E-mail: jlxie@ustc.edu.cn; Yu, C. X.

2016-11-15

Millimeter-wave imaging diagnostics, with large poloidal span and wide radial range, have been developed on the EAST tokamak for visualization of 2D electron temperature and density fluctuations. A 384 channel (24 poloidal × 16 radial) Electron Cyclotron Emission Imaging (ECEI) system in F-band (90-140 GHz) was installed on the EAST tokamak in 2012 to provide 2D electron temperature fluctuation images with high spatial and temporal resolution. A co-located Microwave Imaging Reflectometry (MIR) will be installed for imaging of density fluctuations by December 2016. This “4th generation” MIR system has eight independent frequency illumination beams in W-band (75-110 GHz) driven bymore » fast tuning synthesizers and active multipliers. Both of these advanced millimeter-wave imaging diagnostic systems have applied the latest techniques. A novel design philosophy “general optics structure” has been employed for the design of the ECEI and MIR receiver optics with large aperture. The extended radial and poloidal coverage of ECEI on EAST is made possible by innovations in the design of front-end optics. The front-end optical structures of the two imaging diagnostics, ECEI and MIR, have been integrated into a compact system, including the ECEI receiver and MIR transmitter and receiver. Two imaging systems share the same mid-plane port for simultaneous, co-located 2D fluctuation measurements of electron density and temperature. An intelligent remote-control is utilized in the MIR electronics systems to maintain focusing at the desired radial region even with density variations by remotely tuning the probe frequencies in about 200 μs. A similar intelligent technique has also been applied on the ECEI IF system, with remote configuration of the attenuations for each channel.« less

Millimeter-wave imaging diagnostics systems on the EAST tokamak (invited)

NASA Astrophysics Data System (ADS)

Zhu, Y. L.; Xie, J. L.; Yu, C. X.; Zhao, Z. L.; Gao, B. X.; Chen, D. X.; Liu, W. D.; Liao, W.; Qu, C. M.; Luo, C.; Hu, X.; Spear, A. G.; Luhmann, N. C.; Domier, C. W.; Chen, M.; Ren, X.; Tobias, B. J.

2016-11-01

Millimeter-wave imaging diagnostics, with large poloidal span and wide radial range, have been developed on the EAST tokamak for visualization of 2D electron temperature and density fluctuations. A 384 channel (24 poloidal × 16 radial) Electron Cyclotron Emission Imaging (ECEI) system in F-band (90-140 GHz) was installed on the EAST tokamak in 2012 to provide 2D electron temperature fluctuation images with high spatial and temporal resolution. A co-located Microwave Imaging Reflectometry (MIR) will be installed for imaging of density fluctuations by December 2016. This "4th generation" MIR system has eight independent frequency illumination beams in W-band (75-110 GHz) driven by fast tuning synthesizers and active multipliers. Both of these advanced millimeter-wave imaging diagnostic systems have applied the latest techniques. A novel design philosophy "general optics structure" has been employed for the design of the ECEI and MIR receiver optics with large aperture. The extended radial and poloidal coverage of ECEI on EAST is made possible by innovations in the design of front-end optics. The front-end optical structures of the two imaging diagnostics, ECEI and MIR, have been integrated into a compact system, including the ECEI receiver and MIR transmitter and receiver. Two imaging systems share the same mid-plane port for simultaneous, co-located 2D fluctuation measurements of electron density and temperature. An intelligent remote-control is utilized in the MIR electronics systems to maintain focusing at the desired radial region even with density variations by remotely tuning the probe frequencies in about 200 μs. A similar intelligent technique has also been applied on the ECEI IF system, with remote configuration of the attenuations for each channel.

Inverse multipath fingerprinting for millimeter wave V2I beam alignment.

DOT National Transportation Integrated Search

2017-05-01

Efficient beam alignment is a crucial component in millimeter wave systems with analog beamforming, especially in fast-changing vehicular settings. This paper uses the vehicles position (e.g., available via GPS) to query the multipath fingerprint ...

A quasioptically stabilized resonant-tunneling-diode oscillator for the millimeter- and submillimeter-wave regions

NASA Technical Reports Server (NTRS)

Brown, Elliott R.; Parker, Christopher D.; Molvar, Karen M.; Stephan, Karl D.

1992-01-01

A semiconfocal open-cavity resonator has been used to stabilize a resonant-tunneling-diode waveguide oscillator at frequencies near 100 GHz. The high quality factor of the open cavity resulted in a linewidth of approximately 10 kHz at 10 dB below the peak, which is about 100 times narrower than the linewidth of an unstabilized waveguide oscillator. This technique is well suited for resonant-tunneling-diode oscillators in the submillimeter-wave region.

Dependence of millimeter wave surface resistance on the deposition parameters of laser ablated YBa2Cu3O(x) thin films

NASA Technical Reports Server (NTRS)

Wosik, J.; Robin, T.; Davis, M.; Wolfe, J. C.; Forster, K.; Deshmukh, S.; Bensaoula, A.; Sega, R.; Economou, D.; Ignatiev, A.

1990-01-01

Measurements of millimeter-wave surface resistance versus temperature have been performed for YBa2Cu3O(x) thin films on 100 line-type SrTiO(3) substrates using a TE(011) cylindrical copper cavity at 80 GHz. The 0.6-micron thick films were grown at several deposition temperatures in the range 690 C to 810 C by means of a pulsed excimer laser ablation technique. A surface resistance minimum (60 milliohm at 77 K) near 770 C is shown to correlate with a minimum in c-axis lattice parameter (11.72 A). The highest value of Tc also occurs near this temperature. The surface resistance of films deposited at 790 C on 110 line-type LaAlO3 subtrates is lower, reaching 8 milliohm at 98 GHz and 80 K, demonstrating the influence of substate material on film quality.

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.

Advanced millimeter wave imaging systems

NASA Technical Reports Server (NTRS)

Schuchardt, J. M.; Gagliano, J. A.; Stratigos, J. A.; Webb, L. L.; Newton, J. M.

1980-01-01

Unique techniques are being utilized to develop self-contained imaging radiometers operating at single and multiple frequencies near 35, 95 and 183 GHz. These techniques include medium to large antennas for high spatial resolution, lowloss open structures for RF confinemnt and calibration, wide bandwidths for good sensitivity plus total automation of the unit operation and data collection. Applications include: detection of severe storms, imaging of motor vehicles, and the remote sensing of changes in material properties.

Background characterization techniques for target detection using scene metrics and pattern recognition

NASA Astrophysics Data System (ADS)

Noah, Paul V.; Noah, Meg A.; Schroeder, John W.; Chernick, Julian A.

1990-09-01

The U.S. Army has a requirement to develop systems for the detection and identification of ground targets in a clutter environment. Autonomous Homing Munitions (AHM) using infrared, visible, millimeter wave and other sensors are being investigated for this application. Advanced signal processing and computational approaches using pattern recognition and artificial intelligence techniques combined with multisensor data fusion have the potential to meet the Army's requirements for next generation ARM.

Millimeter-Wave Generation with Spiraling Electron Beams

DOT National Transportation Integrated Search

1971-02-01

An investigation has been carried out of the feasibility : of using the interaction between a thin, solid, : spiraling electron beam of 10-20kV energy and a microwave : cavity to generate watts of CW millimeter-wave power. : Experimental results are ...

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.

Millimeter-wave optical double resonance schemes for rapid assignment of perturbed spectra, with applications to the C{sup ~} {sup 1}B{sub 2} state of SO{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, G. Barratt, E-mail: barratt@mit.edu, E-mail: barratt.park@gmail.com; Womack, Caroline C.; Jiang, Jun

2015-04-14

Millimeter-wave detected, millimeter-wave optical double resonance (mmODR) spectroscopy is a powerful tool for the analysis of dense, complicated regions in the optical spectra of small molecules. The availability of cavity-free microwave and millimeter wave spectrometers with frequency-agile generation and detection of radiation (required for chirped-pulse Fourier-transform spectroscopy) opens up new schemes for double resonance experiments. We demonstrate a multiplexed population labeling scheme for rapid acquisition of double resonance spectra, probing multiple rotational transitions simultaneously. We also demonstrate a millimeter-wave implementation of the coherence-converted population transfer scheme for background-free mmODR, which provides a ∼10-fold sensitivity improvement over the population labeling scheme.more » We analyze perturbations in the C{sup ~} state of SO{sub 2}, and we rotationally assign a b{sub 2} vibrational level at 45 328 cm{sup −1} that borrows intensity via a c-axis Coriolis interaction. We also demonstrate the effectiveness of our multiplexed mmODR scheme for rapid acquisition and assignment of three predissociated vibrational levels of the C{sup ~} state of SO{sub 2} between 46 800 and 47 650 cm{sup −1}.« less

Millimeter-Wave Polarimeters Using Kinetic Inductance Detectors for TolTEC and Beyond

NASA Astrophysics Data System (ADS)

Austermann, J. E.; Beall, J. A.; Bryan, S. A.; Dober, B.; Gao, J.; Hilton, G.; Hubmayr, J.; Mauskopf, P.; McKenney, C. M.; Simon, S. M.; Ullom, J. N.; Vissers, M. R.; Wilson, G. W.

2018-05-01

Microwave kinetic inductance detectors (MKIDs) provide a compelling path forward to the large-format polarimeter, imaging, and spectrometer arrays needed for next-generation experiments in millimeter-wave cosmology and astronomy. We describe the development of feedhorn-coupled MKID detectors for the TolTEC millimeter-wave imaging polarimeter being constructed for the 50-m Large Millimeter Telescope (LMT). Observations with TolTEC are planned to begin in early 2019. TolTEC will comprise ˜ 7000 polarization-sensitive MKIDs and will represent the first MKID arrays fabricated and deployed on monolithic 150 mm diameter silicon wafers—a critical step toward future large-scale experiments with over 10^5 detectors. TolTEC will operate in observational bands at 1.1, 1.4, and 2.0 mm and will use dichroic filters to define a physically independent focal plane for each passband, thus allowing the polarimeters to use simple, direct-absorption inductive structures that are impedance matched to incident radiation. This work is part of a larger program at NIST-Boulder to develop MKID-based detector technologies for use over a wide range of photon energies spanning millimeter-waves to X-rays. We present the detailed pixel layout and describe the methods, tools, and flexible design parameters that allow this solution to be optimized for use anywhere in the millimeter and sub-millimeter bands. We also present measurements of prototype devices operating in the 1.1 mm band and compare the observed optical performance to that predicted from models and simulations.

Error analysis applied to several inversion techniques used for the retrieval of middle atmospheric constituents from limb-scanning MM-wave spectroscopic measurements

NASA Technical Reports Server (NTRS)

Puliafito, E.; Bevilacqua, R.; Olivero, J.; Degenhardt, W.

1992-01-01

The formal retrieval error analysis of Rodgers (1990) allows the quantitative determination of such retrieval properties as measurement error sensitivity, resolution, and inversion bias. This technique was applied to five numerical inversion techniques and two nonlinear iterative techniques used for the retrieval of middle atmospheric constituent concentrations from limb-scanning millimeter-wave spectroscopic measurements. It is found that the iterative methods have better vertical resolution, but are slightly more sensitive to measurement error than constrained matrix methods. The iterative methods converge to the exact solution, whereas two of the matrix methods under consideration have an explicit constraint, the sensitivity of the solution to the a priori profile. Tradeoffs of these retrieval characteristics are presented.

Advanced density profile reflectometry; the state-of-the-art and measurement prospects for ITER

NASA Astrophysics Data System (ADS)

Doyle, E. J.

2006-10-01

Dramatic progress in millimeter-wave technology has allowed the realization of a key goal for ITER diagnostics, the routine measurement of the plasma density profile from millimeter-wave radar (reflectometry) measurements. In reflectometry, the measured round-trip group delay of a probe beam reflected from a plasma cutoff is used to infer the density distribution in the plasma. Reflectometer systems implemented by UCLA on a number of devices employ frequency-modulated continuous-wave (FM-CW), ultrawide-bandwidth, high-resolution radar systems. One such system on DIII-D has routinely demonstrated measurements of the density profile over a range of electron density of 0-6.4x10^19,m-3, with ˜25 μs time and ˜4 mm radial resolution, meeting key ITER requirements. This progress in performance was made possible by multiple advances in the areas of millimeter-wave technology, novel measurement techniques, and improved understanding, including: (i) fast sweep, solid-state, wide bandwidth sources and power amplifiers, (ii) dual polarization measurements to expand the density range, (iii) adaptive radar-based data analysis with parallel processing on a Unix cluster, (iv) high memory depth data acquisition, and (v) advances in full wave code modeling. The benefits of advanced system performance will be illustrated using measurements from a wide range of phenomena, including ELM and fast-ion driven mode dynamics, L-H transition studies and plasma-wall interaction. The measurement capabilities demonstrated by these systems provide a design basis for the development of the main ITER profile reflectometer system. This talk will explore the extent to which these reflectometer system designs, results and experience can be translated to ITER, and will identify what new studies and experimental tests are essential.

IMPATT Diodes Based on 〈111〉, 〈100〉, and 〈110〉 Oriented GaAs: A Comparative Study to Search the Best Orientation for Millimeter-Wave Atmospheric Windows

PubMed Central

Banerjee, Bhadrani; Tripathi, Anvita; Das, Adrija; Singh, Kumari Alka; Banerjee, J. P.

2015-01-01

The authors have carried out the large-signal (L-S) simulation of double-drift region (DDR) impact avalanche transit time (IMPATT) diodes based on 〈111〉, 〈100〉, and 〈110〉 oriented GaAs. A nonsinusoidal voltage excited (NSVE) L-S simulation technique is used to investigate both the static and L-S performance of the above-mentioned devices designed to operate at millimeter-wave (mm-wave) atmospheric window frequencies, such as 35, 94, 140, and 220 GHz. Results show that 〈111〉 oriented GaAs diodes are capable of delivering maximum RF power with highest DC to RF conversion efficiency up to 94 GHz; however, the L-S performance of 〈110〉 oriented GaAs diodes exceeds their other counterparts while the frequency of operation increases above 94 GHz. The results presented in this paper will be helpful for the future experimentalists to choose the GaAs substrate of appropriate orientation to fabricate DDR GaAs IMPATT diodes at mm-wave frequencies. PMID:27347524

An accurate automated technique for quasi-optics measurement of the microwave diagnostics for fusion plasma

NASA Astrophysics Data System (ADS)

Hu, Jianqiang; Liu, Ahdi; Zhou, Chu; Zhang, Xiaohui; Wang, Mingyuan; Zhang, Jin; Feng, Xi; Li, Hong; Xie, Jinlin; Liu, Wandong; Yu, Changxuan

2017-08-01

A new integrated technique for fast and accurate measurement of the quasi-optics, especially for the microwave/millimeter wave diagnostic systems of fusion plasma, has been developed. Using the LabVIEW-based comprehensive scanning system, we can realize not only automatic but also fast and accurate measurement, which will help to eliminate the effects of temperature drift and standing wave/multi-reflection. With the Matlab-based asymmetric two-dimensional Gaussian fitting method, all the desired parameters of the microwave beam can be obtained. This technique can be used in the design and testing of microwave diagnostic systems such as reflectometers and the electron cyclotron emission imaging diagnostic systems of the Experimental Advanced Superconducting Tokamak.

A millimeter-wave reflection-beam isolator

NASA Technical Reports Server (NTRS)

Kanda, M.; May, W. G.

1975-01-01

A new and simple type of millimeter-wave isolator using a solid-state magnetoplasma in a reflection-beam system is described. Some data are presented showing performance at 94 GHz. Practical considerations indicate that performance should be much closer to ideal at higher frequencies.

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

Investigation of radiant millimeter wave/terahertz radiation from low-infrared signature targets

NASA Astrophysics Data System (ADS)

Aytaç, B.; Alkuş, Ü.; Sivaslıgil, M.; Şahin, A. B.; Altan, H.

2017-10-01

Millimeter (mm) and sub-mm wave radiation is increasingly becoming a region of interest as better methods are developed to detect in this wavelength range. The development of sensitive focal plane array (FPA) architectures as well as single pixel scanners has opened up a new field of passive detection and imaging. Spectral signatures of objects, a long standing area of interest in the Short Wave Infrared (SWIR), Mid-Wave (MWIR) and Long Wave-IR (LWIR) bands can now be assessed in the mm-wave/terahertz (THz) region. The advantage is that this form of radiation is not as adversely affected by poor atmospheric conditions compared to other bands. In this study, a preliminary experiment in a laboratory environment is performed to assess the radiance from targets with low infrared signatures in the millimeter wave/terahertz (THz) band (<1 THz). The goal of this approach is to be able to model the experimental results to better understand the mm-wave/THz signature of targets with low observability in the IR bands.

International Conference on Infrared and Millimeter Waves, 16th, Ecole Polytechnique Federale de Lausanne, Switzerland, Aug. 26-30, 1991, Conference Digest

NASA Astrophysics Data System (ADS)

Siegrist, M. R.; Tran, T. M.; Tran, M. Q.

1991-10-01

Consideration is given to millimeter waves (MMW), submillimeter waves, materials properties, and gyrotrons/FEL. Particular attention is given to MMW sources, detectors and mixers; MMW systems, devices and antennas; guided propagation; high Tc superconductors; semiconductors; MMW astronomy and atmospheric physics; lasers, submillimeter devices, and plasma diagnostics; and submillimeter detectors.

Millimeter Wave Radar Clutter Program

DTIC Science & Technology

1989-10-30

conduct experimental measurments and develop theoretical models to Improve our understanding of electromagnetic wave interaction with terrain at...various types of terrain under a variety of conditions. The experimental data servos to guide the development of the models as well as to verify their... experimental measurement. Task 4 - Examination of Bistatic Scattering from Surfaces and Volumes: Prior to this program, no millimeter-wave bistatic

Millimeter Wave Nonreciprocal Devices.

DTIC Science & Technology

1983-01-03

measures microwave magnetic field patterns of magnetostatic waves in LPE -YIG thin films has been developed. The probe’s sensing element is either a...Morgenthaler, "Workshop on Application of Garnet and Ferrite Thin Films to Microwave Devices," Session FC, Third Joint Intermag - Magnetism and...thin films Li... millimeter waves magnetostati c waves i A TRAC" =CmE4 F*91040 eEp y mnenu -d Dfenvely by Noek n.m--) The Microwave and Quantum

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.

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.

Strip dielectric wave guide antenna-for the measurement of dielectric constant of low-loss materials

NASA Astrophysics Data System (ADS)

Rastogi, Alok Kumar; Tiwari, A. K.; Shrivastava, R. P.

1993-07-01

The value of dielectric constant are the most important parameters in material science technology. In micro-wave and millimeter wave circuits using dielectric materials the values of this parameters should be known accurately. It is observed that the number of methods are reported in litrature, however these methods impose difficulties in experimentation and are not very accurate. In this paper a novel approach to the measurement of the dielectric constant of low loss materials at micro-wave and millimeter wave frequencies has been discussed. In this method by using antenna theory, a metallic strip dielectric guide is taken in to constideration and band reject phenomenon of dielectric antenna is used. Frequency response of an antenna in band reject mode is a function of the dimensional parameters, such as the metallic strip period, the profile of the metallic strip and the dielectric constant of the material used. Hence if one measure the frequency responce of the antenna in band reject mode, the dielectric constant of the material is determined provided all other parameters are known. This method gives a direct measure of dielectric constant and is quite accurate as computer techniques are used for evaluating the dielectric constant. This method verified experimentally also.

Broad-bandwidth Metamaterial Antireflection Coatings for Sub-Millimeter Astronomy and CMB Foreground Removal

NASA Astrophysics Data System (ADS)

McMahon, Jeff

Sub-millimeter observations are crucial for answering questions about star and galaxy formation; understanding galactic dust foregrounds; and for removing these foregrounds to detect the faint signature of inflationary gravitational waves in the polarization of the Cosmic Microwave Background (CMB). Achieving these goals requires improved, broad-band antireflection coated lenses and half-wave plates (HWPs). These optical elements will significantly boost the sensitivity and capability of future sub-millimeter and CMB missions. We propose to develop wide-bandwidth metamaterial antireflection coatings for silicon lenses and sapphire HWPs with 3:1 ratio bandwidth that are scalable across the sub-millimeter band from 300 GHz to 3 THz. This is an extension of our successful work on saw cut metamaterial AR coatings for silicon optics at millimeter wave lengths. These, and the proposed coatings consist of arrays of sub-wavelength scale features cut into optical surfaces that behave like simple dielectrics. We have demonstrated saw cut 3:1 bandwidth coatings on silicon lenses, but these coatings are limited to the millimeter wave band by the limitations of dicing saw machining. The crucial advance needed to extend these broad band coatings throughout the sub-millimeter band is the development of laser cut graded index metamaterial coatings. The proposed work includes developing the capability to fabricate these coatings, optimizing the design of these metamaterials, fabricating and testing prototype lenses and HWPs, and working with the PIPER collaboration to achieve a sub-orbital demonstration of this technology. The proposed work will develop potentially revolutionary new high performance coatings for the sub-millimeter bands, and cary this technology to TRL 7 paving the way for its use in space. We anticipate that there will be a wide range of applications for these coatings on future NASA balloons and satellites.

Detection of small metal particles by a quasi-optical system at sub-millimeter wavelength

NASA Astrophysics Data System (ADS)

Kitahara, Yasuyuki; Domier, C. W.; Ikeda, Makoto; Pham, Anh-Vu; Luhmann, Neville C.

2016-04-01

Inspection of alien metal particles in electronic materials such as glass fibers and resins is a critical issue to control the quality and guarantee the safety of products. In this paper, we present a new detection technique using sub-millimeter wave for films as electric materials in product lines. The advantage of using sub-millimeter wave frequency is that it is easy to distinguish conductive particles from a nonconductive material such as plastic films. Scattering of a submillimeter wave by a metal particle is used as the detection principle. By simulation, it is observed that the scattering pattern varies intricately as the diameter varies from 10 to 700 μm at 300 GHz. The demonstration system is composed of a Keysight performance network analyzer (N5247A PNA-X) with 150-330 GHz VDI extension modules, transmitting and receiving antennas, and focusing dielectric lens. An output signal is radiated via an antenna and focused onto a metal particle on a film. The wave scattered by the metal particle is detected by an identical antenna through a lens. The signal scattered from a metal particle is evaluated from the insertion loss between antennas (S21). The result shows that a particle of diameter 300 μm is detectable at 150-330 GHz through S21 in the experimental system that we prepared. Peaks calculated in simulation were detected in experimental data as well as in the curves of the particle diameter versus S21. It was shown that using this peak frequency could improve S21 level without higher frequency.

1990 MTT-S International Microwave Symposium and Exhibition and Microwave and Millimeter-Wave Monolithic IC Symposium, Dallas, TX, May 7-10, 1990, Proceedings

NASA Astrophysics Data System (ADS)

McQuiddy, David N., Jr.; Sokolov, Vladimir

1990-12-01

The present conference discusses microwave filters, lightwave technology for microwave antennas, planar and quasi-planar guides, mixers and VCOs, cavity filters, discontinuity and coupling effects, control circuits, power dividers and phase shifters, microwave ICs, biological effects and medical applications, CAD and modeling for MMICs, directional couplers, MMIC design trends, microwave packaging and manufacturing, monolithic ICs, and solid-state devices and circuits. Also discussed are microwave and mm-wave superconducting technology, MICs for communication systems, the merging of optical and microwave technologies, microwave power transistors, ferrite devices, network measurements, advanced transmission-line structures, FET devices and circuits, field theory of IC discontinuities, active quasi-optical techniques, phased-array techniques and circuits, nonlinear CAD, sub-mm wave devices, and high power devices.

Millimeter-wave spectroscopy of the SiCl+ ion

NASA Astrophysics Data System (ADS)

Takeda, Kazuki; Masuda, Satoshi; Harada, Kensuke; Tanaka, Keiichi

2016-05-01

The millimeter-wave spectrum of the SiCl+ ion in the ground and first excited vibrational states was observed for the two isotopic (35Cl and 37Cl) species. The ion was generated in a free-space absorption cell by a hollow cathode discharge of SiCl4 diluted with He and discriminated from neutral species by the magnetic field effect on the absorption lines. The observed millimeter-wave spectrum was combined with a previously reported diode laser spectrum in an analysis to determine mass-independent Dunham coefficients as well as the mass scaling parameters. The equilibrium bond length of SiCl+ determined is re = 1.943 978(2) Å.

Submillimeter Laboratory Investigations: Spectroscopy and Collisions

NASA Technical Reports Server (NTRS)

Herbst, Eric; DeLucia, Frank C.

2002-01-01

Currently, millimeter-wave and submillimeter-wave spectroscopy is conducted in our laboratory on several different types of spectrometers. Our standard spectrometer utilizes the output of a phase-locked klystron operating in the 40-60 GHz region, which is sent into a crossed-waveguide harmonic generator, or "multiplier". The high frequency millimeter-and submillimeter-wave radiation is transmitted via quasi-optical techniques through an absorption cell and then onto a detector, which is either an InSb hot electron bolometer cooled to 1.4 K or a Si bolometer cooled to 0.3 K. The detector response is sent to a computer for measurement and analysis. The frequency range produced and detected in this manner goes from 80 GHz to upwards of 1 THz. Spectra are normally taken with source modulation, with line frequencies typically measured to an accuracy of 50-100 kHz. Higher accuracy is available when needed. Recently, we developed a new, broad-band spectrometer in our laboratory based on a free-running backward wave oscillator (BWO) of Russian manufacture as the primary source of radiation. The so-called FASSST (fast-scan submillimeter spectroscopic technique) system uses fast-scan and optical calibration methods rather than the traditional locking techniques. The output power from the BWO is split such that 90% goes into the absorption cell while 10% is coupled to a 40-meter Fabry-Perot cavity, which yields fringe? for frequency measurement. Results from this spectrometer on the spectrum of nitric acid (HNO3) show that 100 GHz of spectral data can be obtained in 5 seconds with a measurement accuracy of 50 kHz. Currently, the frequency range of the FASSST system in our laboratory is roughly 100-700 GHz.

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.

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.

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.

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.

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.

Millimeter Wave Spectroscopy in a Semi-Confocal Fabry-Perot Cavity

NASA Astrophysics Data System (ADS)

Drouin, Brian; Tang, Adrian; Reck, Theodore J.; Nemchick, Deacon J.; Cich, Matthew J.; Crawford, Timothy J.; Raymond, Alexander W.; Chang, M.-C. Frank; Kim, Rod M.

2017-06-01

A new generation of CMOS circuits operating at 89-104 GHz with improved output power and pulse switch isolation have enhanced the performance of the miniaturized pulsed-echo Fourier transform spectrometer under development for planetary exploration at the Jet Propulsion laboratory. Additional progress has been made by creating a waveguide-fed structure for the novel planar coupler design. This structure has enabled characterization of each component in the system and enabled spectroscopy to be done with conventional millimeter hardware that enables (1) direct comparisons to the CMOS components, (2) enhanced bandwidth of 74-109 GHz, and (3) amplification of the transmitter prior to cavity injection. We have now demonstrated the technique with room temperature detections on multiple species including N_2O, OCS, CH_3CN, CH_3OH, CH_3NH_2, CH_3CHO, CH_3Cl, HDO, D_2O, CH_3CH_2CN and CH_3CH_2OH. Of particular interest to spectroscopic work in the millimeter range is the ongoing incorporation of a ΔΣ radio-frequency source into the millimeter-wave lock-loop - this has improved the phase-noise of the tunable CMOS transceiver to better than the room-temperature Doppler limit and provides a promising source for general use that may replace the high end microwave synthesizers. We are in the process of building a functional interface to the various subsystems. We will present a trade-space study to determine the optimal operating conditions of the pulse-echo system.

An evaluation of HEMT potential for millimeter-wave signal sources using interpolation and harmonic balance techniques

NASA Technical Reports Server (NTRS)

Kwon, Youngwoo; Pavlidis, Dimitris; Tutt, Marcel N.

1991-01-01

A large-signal analysis method based on an harmonic balance technique and a 2-D cubic spline interpolation function has been developed and applied to the prediction of InP-based HEMT oscillator performance for frequencies extending up to the submillimeter-wave range. The large-signal analysis method uses a limited number of DC and small-signal S-parameter data and allows the accurate characterization of HEMT large-signal behavior. The method has been validated experimentally using load-pull measurement. Oscillation frequency, power performance, and load requirements are discussed, with an operation capability of 300 GHz predicted using state-of-the-art devices (fmax is approximately equal to 450 GHz).

Effects of atmospheric turbulence on microwave and millimeter wave satellite communications systems. [attenuation statistics and antenna design

NASA Technical Reports Server (NTRS)

Devasirvatham, D. M. J.; Hodge, D. B.

1981-01-01

A model of the microwave and millimeter wave link in the presence of atmospheric turbulence is presented with emphasis on satellite communications systems. The analysis is based on standard methods of statistical theory. The results are directly usable by the design engineer.

International Conference on Infrared and Millimeter Waves, 13th, Honolulu, HI, Dec. 5-9, 1988, Conference Digest

NASA Astrophysics Data System (ADS)

Temkin, Richard J.

Recent advances in IR and mm-wave (MMW) physics, astrophysics, devices, and applications are examined in reviews and reports. Sections are devoted to MMW sources, MMW modulation of light, MMW antennas, FELs, MMW optical technology, astronomy, MMW systems, microwave-optical interactions, MMW waveguides, MMW detectors and mixers, plasma diagnostics, and atmospheric physics. Also considered are gyrotrons, guided propagation, high-Tc superconductors, sub-MMW detectors and related devices, ICs, near-MMW measurements and techniques, lasers, material characterization, semiconductors, and atmospheric propagation.

International Conference on Infrared and Millimeter Waves, 15th, Orlando, FL, Dec. 10-14, 1990, Conference Digest

NASA Astrophysics Data System (ADS)

Temkin, Richard J.

Recent advances in IR and mm-wave (MMW) technology and applications are discussed in reviews and reports. Sections are devoted to MMW sources, high-Tc superconductors, atmospheric physics, FEL technology, astronomical instrumentation, MMW systems, measurement techniques, MMW guides, and MMW detectors and mixers. Also discussed are material properties, gyrotrons, guided propagation, semiconductors, submm detectors and devices, material characterization methods, ICs, MMW guides and plasma diagnostics, lasers, and MMW antennas. Diagrams, drawings, graphs, photographs, and tables of numerical data are provided.

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.

Introduction to the physics and techniques of remote sensing

NASA Technical Reports Server (NTRS)

Elachi, Charles

1987-01-01

This book presents a comprehensive overview of the basics behind remote-sensing physics, techniques, and technology. The physics of wave/matter interactions, techniques of remote sensing across the electromagnetic spectrum, and the concepts behind remote sensing techniques now established and future ones under development are discussed. Applications of remote sensing are described for a wide variety of earth and planetary atmosphere and surface sciences. Solid surface sensing across the electromagnetic spectrum, ocean surface sensing, basic principles of atmospheric sensing and radiative transfer, and atmospheric remote sensing in the microwave, millimeter, submillimeter, and infrared regions are examined.

The Application of the FDTD Method to Millimeter-Wave Filter Circuits Including the Design and Analysis of a Compact Coplanar

NASA Technical Reports Server (NTRS)

Oswald, J. E.; Siegel, P. H.

1994-01-01

The finite difference time domain (FDTD) method is applied to the analysis of microwave, millimeter-wave and submillimeter-wave filter circuits. In each case, the validity of this method is confirmed by comparison with measured data. In addition, the FDTD calculations are used to design a new ultra-thin coplanar-strip filter for feeding a THz planar-antenna mixer.

Comparison between broadband Bessel beam launchers based on either Bessel or Hankel aperture distribution for millimeter wave short pulse generation.

PubMed

Pavone, Santi C; Mazzinghi, Agnese; Freni, Angelo; Albani, Matteo

2017-08-07

In this paper, a comparison is presented between Bessel beam launchers at millimeter waves based on either a cylindrical standing wave (CSW) or a cylindrical inward traveling wave (CITW) aperture distribution. It is theoretically shown that CITW launchers are better suited for the generation of electromagnetic short pulses because they maintain their performances over a larger bandwidth than those realizing a CSW aperture distribution. Moreover, the wavenumber dispersion of both the launchers is evaluated both theoretically and numerically. To this end, two planar Bessel beam launchers, one enforcing a CSW and the other enforcing a CITW aperture distribution, are designed at millimeter waves with a center operating frequency of f¯=60GHz and analyzed in the bandwidth 50 - 70 GHz by using an in-house developed numerical code to solve Maxwell's equations based on the method of moments. It is shown that a monochromatic Bessel beam can be efficiently generated by both the launchers over a wide fractional bandwidth. Finally, we investigate the generation of limited-diffractive electromagnetic pulses at millimeter waves, up to a certain non-diffractive range. Namely, it is shown that by feeding the launcher with a Gaussian short pulse, a spatially confined electromagnetic pulse can be efficiently generated in front of the launcher.

Development and Short-Range Testing of a 100 kW Side-Illuminated Millimeter-Wave Thermal Rocket

NASA Technical Reports Server (NTRS)

Bruccoleri, Alexander; Eilers, James A.; Lambot, Thomas; Parkin, Kevin

2015-01-01

The objective of the phase described here of the Millimeter-Wave Thermal Launch System (MTLS) Project was to launch a small thermal rocket into the air using millimeter waves. The preliminary results of the first MTLS flight vehicle launches are presented in this work. The design and construction of a small thermal rocket with a planar ceramic heat exchanger mounted along the axis of the rocket is described. The heat exchanger was illuminated from the side by a millimeter-wave beam and fed propellant from above via a small tank containing high pressure argon or nitrogen. Short-range tests where the rocket was launched, tracked, and heated with the beam are described. The rockets were approximately 1.5 meters in length and 65 millimeters in diameter, with a liftoff mass of 1.8 kilograms. The rocket airframes were coated in aluminum and had a parachute recovery system activated via a timer and Pyrodex. At the rocket heat exchanger, the beam distance was 40 meters with a peak power intensity of 77 watts per square centimeter. and a total power of 32 kilowatts in a 30 centimeter diameter circle. An altitude of approximately 10 meters was achieved. Recommendations for improvements are discussed.

Quantum-limited detection of millimeter waves using superconducting tunnel junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mears, Carl Atherton

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 bymore » 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 ± 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.« less

Quantum-limited detection of millimeter waves using superconducting tunnel junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 bymore » 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.« less

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.

Open nonradiative cavities as millimeter wave single-mode resonators

NASA Astrophysics Data System (ADS)

Annino, G.; Cassettari, M.; Martinelli, M.

2005-06-01

Open single-mode metallic cavities operating in nonradiative configurations are proposed and demonstrated. Starting from well-known dielectric resonators, possible nonradiative cavities have been established; their behavior on the fundamental TE011 mode has been predicted on the basis of general considerations. As a result, very efficient confinement properties are expected for a wide variety of open structures having rotational invariance. Test cavities realized having in mind practical millimeter wave constraints have been characterized at microwave frequencies. The obtained results confirm the expected high performances on widely open configurations. A possible excitation of the proposed resonators exploiting their nonradiative character is discussed, and the resulting overall ease of realization enlightened in view of millimeter wave employments.

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.

Location of γ-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 More than 14 pc from the Central Engine

NASA Astrophysics Data System (ADS)

Agudo, Iván; Jorstad, Svetlana G.; Marscher, Alan P.; Larionov, Valeri M.; Gómez, José L.; Lähteenmäki, Anne; Gurwell, Mark; Smith, Paul S.; Wiesemeyer, Helmut; Thum, Clemens; Heidt, Jochen; Blinov, Dmitriy A.; D'Arcangelo, Francesca D.; Hagen-Thorn, Vladimir A.; Morozova, Daria A.; Nieppola, Elina; Roca-Sogorb, Mar; Schmidt, Gary D.; Taylor, Brian; Tornikoski, Merja; Troitsky, Ivan S.

2011-01-01

We combine time-dependent multi-waveband flux and linear polarization observations with submilliarcsecond-scale polarimetric images at λ = 7 mm of the BL Lacertae type blazar OJ287 to locate the γ-ray emission in prominent flares in the jet of the source >14 pc from the central engine. We demonstrate a highly significant correlation between the strongest γ-ray and millimeter-wave flares through Monte Carlo simulations. The two reported γ-ray peaks occurred near the beginning of two major millimeter-wave outbursts, each of which is associated with a linear polarization maximum at millimeter wavelengths. Our very long baseline array observations indicate that the two millimeter-wave flares originated in the second of two features in the jet that are separated by >14 pc. The simultaneity of the peak of the higher-amplitude γ-ray flare and the maximum in polarization of the second jet feature implies that the γ-ray and millimeter-wave flares are cospatial and occur >14 pc from the central engine. We also associate two optical flares, accompanied by sharp polarization peaks, with the two γ-ray events. The multi-waveband behavior is most easily explained if the γ-rays arise from synchrotron self-Compton scattering of optical photons from the flares. We propose that flares are triggered by interaction of moving plasma blobs with a standing shock. The γ-ray and optical emission is quenched by inverse Compton losses as synchrotron photons from the newly shocked plasma cross the emission region. The millimeter-wave polarization is high at the onset of a flare, but decreases as the electrons emitting at these wavelengths penetrate less polarized regions.

Evaluation of concrete cover by surface wave technique: Identification procedure

NASA Astrophysics Data System (ADS)

Piwakowski, Bogdan; Kaczmarek, Mariusz; Safinowski, Paweł

2012-05-01

Concrete cover degradation is induced by aggressive agents in ambiance, such as moisture, chemicals or temperature variations. Due to degradation usually a thin (a few millimeters thick) surface layer has porosity slightly higher than the deeper sound material. The non destructive evaluation of concrete cover is vital to monitor the integrity of concrete structures and prevent their irreversible damage. In this paper the methodology applied by the classical technique used for ground structure recovery called Multichanel Analysis of Surface Waves is discussed as the NDT tool in civil engineering domain to characterize the concrete cover. In order to obtain the velocity as a function of sample depth the dispersion of surface waves is used as an input for solving inverse problem. The paper describes the inversion procedure and provides the practical example of use of developed system.

Profiling of Atmospheric Water Vapor with MIR and LASE

NASA Technical Reports Server (NTRS)

Wang, J. R.; Racette, P.; Triesly, M. E.; Browell, E. V.; Ismail, S.; Chang, L. A.; Hildebrand, Peter H. (Technical Monitor)

2001-01-01

This paper presents the first and the only simultaneous measurements of water vapor by MIR (Millimeter-wave Imaging Radiometer) and LASE (Lidar Atmospheric Sounding Experiment) on board the same ER-2 aircraft. Water vapor is one of the most important constituents in the Earth's atmosphere, as its spatial and temporal variations affect a wide spectrum of meteorological phenomena ranging from the formation of clouds to the development of severe storms. Its concentration, as measured in terms of relative humidity, determines the extinction coefficient of atmospheric aerosol particles and therefore visibility. These considerations point to the need for effective and frequent measurements of the atmospheric water vapor. The MIR and LASE instruments provide measurements of water vapor profiles with two markedly different techniques. LASE can give water vapor profiles with excellent vertical resolution under clear condition, while MIR can retrieve water vapor profiles with a crude vertical resolution even under a moderate cloud cover. Additionally, millimeter-wave measurements are relatively simple and provide better spatial coverage.

International Conference on Optical and Millimeter Wave Propagation and Scattering in the Atmosphere Held in Florence, Italy on 27-30 May 1986

DTIC Science & Technology

1986-05-01

Solutions for the second moment gen - erated by this technique were found to have enough spectral content to describe phenomena near caustics if the...Beam Wander in the TIrbulent ?Wear-earth Atmronbere P27 qonr- 7hen. fanc Anhui Institute of Ontics ane Pine Mpchanics, Academia Sinica, P. 0. Box 25

Depolarization on Earth-space paths

NASA Technical Reports Server (NTRS)

1981-01-01

Sources of depolarization effects on the propagation paths of orthogonally-polarized information channels are considered. The main sources of depolarization at millimeter wave frequencies are hydrometeor absorption and scattering in the troposphere. Terms are defined. Mathematical formulations for the effects of the propagation medium characteristics and antenna performance on signals in dual polarization Earth-space links are presented. Techniques for modeling rain and ice depolarization are discussed.

Wide-bandwidth, wide-beamwidth, high-resolution, millimeter-wave imaging for concealed weapon detection

NASA Astrophysics Data System (ADS)

Sheen, David M.; Fernandes, Justin L.; Tedeschi, Jonathan R.; McMakin, Douglas L.; Jones, A. Mark; Lechelt, Wayne M.; Severtsen, Ronald H.

2013-05-01

Active millimeter-wave imaging is currently being used for personnel screening at airports and other high-security facilities. The cylindrical imaging techniques used in the deployed systems are based on licensed technology developed at the Pacific Northwest National Laboratory. The cylindrical and a related planar imaging technique form three-dimensional images by scanning a diverging beam swept frequency transceiver over a two-dimensional aperture and mathematically focusing or reconstructing the data into three-dimensional images of the person being screened. The resolution, clothing penetration, and image illumination quality obtained with these techniques can be significantly enhanced through the selection of the aperture size, antenna beamwidth, center frequency, and bandwidth. The lateral resolution can be improved by increasing the center frequency, or it can be increased with a larger antenna beamwidth. The wide beamwidth approach can significantly improve illumination quality relative to a higher frequency system. Additionally, a wide antenna beamwidth allows for operation at a lower center frequency resulting in less scattering and attenuation from the clothing. The depth resolution of the system can be improved by increasing the bandwidth. Utilization of extremely wide bandwidths of up to 30 GHz can result in depth resolution as fine as 5 mm. This wider bandwidth operation may allow for improved detection techniques based on high range resolution. In this paper, the results of an extensive imaging study that explored the advantages of using extremely wide beamwidth and bandwidth are presented, primarily for 10-40 GHz frequency band.

Built-in self-test (BIST) techniques for millimeter wave CMOS transceivers

NASA Astrophysics Data System (ADS)

Mahzabeen, Tabassum

The seamless integration of complementary metal oxide semiconductor (CMOS) transceivers with a digital CMOS process enhances on-chip testability, thus reducing production and testing costs. Built in self testability also improves yield by offering on-chip compensation. This work focuses on built in self test techniques for CMOS based millimeter wave (mm-wave) transceivers. Built-in-self-test (BIST) using the loopback method is one cost-effective method for testing these transceivers. Since the loopback switch is always present during the normal operation of the transceiver, the requirement of the switch is different than for a conventional switch. The switch needs to have high isolation and high impedance during its OFF period. Two 80 GHz single pole single throw (SPST) switches have been designed, fabricated in standard CMOS process, and measured to connect the loopback path for BIST applications. The loopback switches in this work provide the required criteria for loopback BIST. A stand alone 80 GHz low noise amplifier (LNA) and the same LNA integrated with one of the loopback switches have been fabricated, and measured to observe the difference in performance when the loopback switch is present. Besides the loopback switch, substrate leakage also forms a path between the transmitter and receiver. Substrate leakage has been characterized as a function of distance between the transmitter and receiver for consideration in using the BIST method. A BIST algorithm has been developed to estimate the process variation in device sizes by probing a low frequency ring oscillator to estimate the device variation and map this variation to the 80 GHz LNA. Probing a low frequency circuit is cheaper compared to the probing of a millimeter wave circuit and reduces the testing costs. The performance of the LNA degrades due to variation in device size. Once the shift in the device size is being estimated (from the ring oscillator's shifted frequency), the LNA's performance can be recovered using several methods; for example, using tunable transmission line lengths in the amplifier or using a variable supply voltage. This concept of estimating process variation has been demonstrated in Agilent Design System (ADS).

Millimeter wave generation by relativistic electron beams and microwave-plasma interaction

NASA Astrophysics Data System (ADS)

Kuo, Spencer

1990-12-01

The design and operation of a compact, high power, millimeter wave source (cusptron) has been completed and proven successful. Extensive theoretical analysis of cusptron beam and rf dynamics has been carried out and published. Theory agrees beautifully with experiment. Microwave Bragg scattering due to been achieved by using expanding plasmas to upshift rf signal frequencies.

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.

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.

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.

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.

Simulation of millimeter-wave body images and its application to biometric recognition

NASA Astrophysics Data System (ADS)

Moreno-Moreno, Miriam; Fierrez, Julian; Vera-Rodriguez, Ruben; Parron, Josep

2012-06-01

One of the emerging applications of the millimeter-wave imaging technology is its use in biometric recognition. This is mainly due to some properties of the millimeter-waves such as their ability to penetrate through clothing and other occlusions, their low obtrusiveness when collecting the image and the fact that they are harmless to health. In this work we first describe the generation of a database comprising 1200 synthetic images at 94 GHz obtained from the body of 50 people. Then we extract a small set of distance-based features from each image and select the best feature subsets for person recognition using the SFFS feature selection algorithm. Finally these features are used in body geometry authentication obtaining promising results.

Fiber-optic delay-line stabilization of heterodyne optical signal generator and method using same

NASA Technical Reports Server (NTRS)

Logan, Ronald T. (Inventor)

1997-01-01

The present invention is a laser heterodyne frequency generator system with a stabilizer for use in the microwave and millimeter-wave frequency ranges utilizing a photonic mixer as a photonic phase detector in a stable optical fiber delay-line. Phase and frequency fluctuations of the heterodyne laser signal generators are stabilized at microwave and millimeter wave frequencies by a delay line system operating as a frequency discriminator. The present invention is free from amplifier and mixer 1/.function. noise at microwave and millimeter-wave frequencies that typically limit phase noise performance in electronic cavity stabilized electronic oscillators. Thus, 1/.function. noise due to conventional mixers is eliminated and stable optical heterodyne generation of electrical signals is achieved.

Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

NASA Technical Reports Server (NTRS)

Gasiewski, Albin J.; Kunkee, D. B.; Jackson, D. M.; Adelberg, L. K.

1992-01-01

Activities within the period from January 1, 1992 through June 30, 1992 by Georgia Tech researchers in millimeter and submillimeter wavelength tropospheric remote sensing have been centered around the integration and initial data flights of the MIR on board the NASA ER-2. Georgia Tech contributions during this period include completion of the MIR flight software and implementation of a 'quick-view' graphics program for ground based calibration and analysis of the MIR imagery. In the current configuration, the MIR has channels at 90, 150, 183 +/- 1,3,7, and 220 GHz. Provisions for three additional channels at 325 +/-1,3 and 9 GHZ have been made, and a 325-GHz receiver is currently being built by the ZAX Millimeter Wave Corporation for use in the MIR. The combination of the millimeter wave and submillimeter wave channels aboard a single well-calibrated instrument will provide the necessary aircraft radiometric data for radiative transfer and cloud and water vapor retrieval studies. A paper by the PI discussing the potential benefits of passive millimeter and submillimeter wave observations for cloud, water vapor and precipitation measurements has recently been accepted for publication (Gasiewski, 1992), and is included as Appendix A. The MIR instrument is a joint project between NASA/GSFC and Georgia Tech. Other Georgia Tech contributions to the MIR and its related scientific uses have included basic system design studies, performance analyses, and circuit and radiometric load design.

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.

Advances in real-time millimeter-wave imaging radiometers for avionic synthetic vision

NASA Astrophysics Data System (ADS)

Lovberg, John A.; Chou, Ri-Chee; Martin, Christopher A.; Galliano, Joseph A., Jr.

1995-06-01

Millimeter-wave imaging has advantages over conventional visible or infrared imaging for many applications because millimeter-wave signals can travel through fog, snow, dust, and clouds with much less attenuation than infrared or visible light waves. Additionally, passive imaging systems avoid many problems associated with active radar imaging systems, such as radar clutter, glint, and multi-path return. ThermoTrex Corporation previously reported on its development of a passive imaging radiometer that uses an array of frequency-scanned antennas coupled to a multichannel acousto-optic spectrum analyzer (Bragg-cell) to form visible images of a scene through the acquisition of thermal blackbody radiation in the millimeter-wave spectrum. The output from the Bragg cell is imaged by a standard video camera and passed to a computer for normalization and display at real-time frame rates. An application of this system is its incorporation as part of an enhanced vision system to provide pilots with a synthetic view of a runway in fog and during other adverse weather conditions. Ongoing improvements to a 94 GHz imaging system and examples of recent images taken with this system will be presented. Additionally, the development of dielectric antennas and an electro- optic-based processor for improved system performance, and the development of an `ultra- compact' 220 GHz imaging system will be discussed.

Multi Ray Model for Near-Ground Millimeter Wave Radar

PubMed Central

Litvak, Boris; Pinhasi, Yosef

2017-01-01

A quasi-optical multi-ray model for a short-range millimeter wave radar is presented. The model considers multi-path effects emerging while multiple rays are scattered from the target and reflected to the radar receiver. Among the examined scenarios, the special case of grazing ground reflections is analyzed. Such a case becomes relevant when short range anti-collision radars are employed in vehicles. Such radars operate at millimeter wavelengths, and are aimed at the detection of targets located several tens of meters from the transmitter. Reflections from the road are expected to play a role in the received signal strength, together with the direct line-of-sight beams illuminated and scattered from the target. The model is demonstrated experimentally using radar operating in the W-band. Controlled measurements were done to distinguish between several scattering target features. The experimental setup was designed to imitate vehicle near-ground millimeter wave radars operating in vehicles. A comparison between analytical calculations and experimental results is made and discussed. PMID:28867776

Millimeter and submillimeter wave spectroscopy of propanal

NASA Astrophysics Data System (ADS)

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

2017-12-01

The rotational spectra of the two stable conformers syn- and gauche-propanal (CH3CH2CHO) were studied in the millimeter and submillimeter wave regions from 75 to 500 GHz with the Cologne (Sub-)Millimeter wave Spectrometer. Furthermore, the first excited states associated with the aldehyde torsion and with the methyl torsion, respectively, of the syn-conformer were analyzed. The newly obtained spectroscopic parameters yield better predictions, thus fulfill sensitivity and resolution requirements in new astronomical observations in order to unambiguously assign pure rotational transitions of propanal. This is demonstrated on a radio astronomical spectrum from the Atacama Large Millimeter/submillimeter Array Protostellar Interferometric Line Survey (ALMA-PILS). In particular, an accurate description of observed splittings, caused by internal rotation of the methyl group in the syn-conformer and by tunneling rotation interaction from two stable degenerate gauche-conformers, is reported. The rotational spectrum of propanal is of additional interest because of its two large amplitude motions pertaining to the methyl and the aldehyde group, respectively.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul.

PubMed

Alavi, S E; Soltanian, M R K; Amiri, I S; Khalily, M; Supa'at, A S M; Ahmad, H

2016-01-27

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul

PubMed Central

Alavi, S. E.; Soltanian, M. R. K.; Amiri, I. S.; Khalily, M.; Supa’at, A. S. M.; Ahmad, H.

2016-01-01

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated. PMID:26814621

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul

NASA Astrophysics Data System (ADS)

Alavi, S. E.; Soltanian, M. R. K.; Amiri, I. S.; Khalily, M.; Supa'At, A. S. M.; Ahmad, H.

2016-01-01

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.

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 integrated beamformer fabricated using the stacking of PCB boards is shown, and measured results compare favorably with the micromachined front ends. A 3D printed small aperture horn is compared with a conventionally machined horn, and measured results show similar performance with a ten-fold reduction in cost and weight.

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.

Arthritis inflammation monitored by subcutaneous millimeter wave thermography.

PubMed

Edrich, J; Smyth, C J

1978-01-01

A new technique for remote, noninvasive mapping of temperature elevations of the human joints is described; it uses the mm wave radiation emitted by the human body. A solid state switched scanner for 68 GHz is described which overcomes the depth limitations of conventional, infrared thermographs and can measure to subcutaneous depths of several mm with a temperature resolution of 0.25 degrees C. Measurements on rheumatoid arthritic knee joints are presented which show little correlation with simultaneously measured skin temperatures. Significant longterm thermographic changes induced by steroid injection indicate a potential for objective patient monitoring and development of new treatment methods.

Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

NASA Technical Reports Server (NTRS)

Gasiewski, Albin J.; Kunkee, D. B.; Jackson, D. M.; Blackwell, W.; Sharpe, S.

1994-01-01

Progress by the Georgia Institute of Technology's Laboratory for Radio-science and Remote Sensing in developing techniques for passive microwave retrieval of water vapor profiles and cloud and precipitation parameters using millimeter and submillimeter wavelength channels is reviewed. Channels of particular interest are in the tropospheric transmission windows at 90, 166, 220, 340, and 410 GHz and centered around the water vapor lines at 183 and 325 GHz. Collectively, these channels have potential application in high-resolution precipitation mapping (e.g., from geosynchronous orbit), remote sensing of cloud and precipitation parameters, including cirrus ice mass, and improved retrieval of water vapor profiles. During the period from January 1, 1994 through June 30, 1994 research activities focussed on calibrating and interpreting data from the Millimeter-Wave Imaging Radiometer (MIR). The MIR was deployed on the NASA ER-2 during the Convective Atmospheric Moisture Experiment (CAMEX, September-October 1993) to obtain the first submillimeter-wave tropospheric imagery of convective precipitations. A 325-GHz radiometer consisted of a submillimeter-wave DSB receiver with three IF channels at +/- 1, 3, and 8.5 GHz, and approximately 14 dB DSB noise figure was successfully operated during these experiments. Activities supported under this grant include a study of the impact of local oscillator reflections from the MIR calibration loads, the development of optimal gain and offset filters for radiometric calibration, and the modeling and interpretation of the MIR 325-GHz data over both clear and cloudy atmospheres. In addition, polarimetric radiometer measurements and modeling for ocean surface and atmospheric cloud-ice studies_were supported.

Optical millimeter-wave signal generation by frequency quadrupling using one dual-drive Mach-Zehnder modulator to overcome chromatic dispersion

NASA Astrophysics Data System (ADS)

Zhu, Zihang; Zhao, Shanghong; Yao, Zhoushi; Tan, Qinggui; Li, Yongjun; Chu, Xingchun; Shi, Lei; Zhang, Xi

2012-06-01

We propose a novel approach to generate quadrupling-frequency optical millimeter-wave using a dual-drive Mach-Zehnder modulator (MZM) in radio-over-fiber system. By properly adjusting the phase difference in the two modulation arms of MZM, the direct current (DC) bias, the modulation index and the gain of base-band signal, the quadrupling-frequency optical millimeter-wave with signal only carried by one second-order sideband is generated. As the signal is transmitted along the fiber, there is no time shift of the codes caused by chromatic dispersion. Theoretical analysis and simulation results show that the eye diagram keeps open and clear even when the quadrupling-frequency optical millimeter-wave are transmitted over 110 km and the power penalty is about 0.45 dB after fiber transmission distance of 60 km. Furthermore, due to another second-order sideband carrying no signals, a full duplex radio-over-fiber link based on wavelength reuse is also built to simplify the base station. The bidirectional 2.5 Gbit/s data is successfully transmitted over 40 km standard single mode fiber with less than 0.6 dB power penalty in the simulation.

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

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.

Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1991-01-01

Laboratory measurements of microwave and millimeter wave properties of the simulated atmosphere of the outer planets and their satellites has continued. One of the focuses is on the development of a radiative transfer model of the Jovian atmosphere at wavelengths from 1 mm to 10 cm. This modeling effort led to laboratory measurements of the millimeter wave opacity of hydrogen sulfide (H2S) under simulated Jovian conditions. Descriptions of the modeling effort, the Laboratory experiment, and the observations are presented. Correlative studies of measurements with Pioneer-Venus radio occultation measurements with longer wavelength emission measurements have provided new ways for characterizing temporal and spatial variations in the abundance of both gases H2SO4 and SO2, and for modeling their roles in the subcloud atmosphere. Laboratory measurements were conducted on 1.35 cm (and 13 cm) opacity of gaseous SO2 and absorptivity of gaseous SO2 at the 3.2 mm wavelength under simulated Venus conditions. Laboratory measurements were completed on millimeter wave dielectric properties of liquid H2SO4, in order to model the effects of the opacity of the clouds of Venus onto millimeter wave emission spectrum.

Nonlinear optical THz generation and sensing applications

NASA Astrophysics Data System (ADS)

Kawase, Kodo

2012-03-01

We have suggested a wide range of real-life applications using novel terahertz imaging techniques. A high-resolution terahertz tomography was demonstrated by ultra short terahertz pulses using optical fiber and a nonlinear organic crystal. We also report on the thickness measurement of very thin films using high-sensitivity metal mesh filter. Further we have succeeded in a non-destructive inspection that can monitor the soot distribution in the ceramic filter using millimeter-to-terahertz wave computed tomography. These techniques are directly applicable to the non-destructive testing in industries.

Interaction Structures for Narrow-Band Millimeter-Wave Communications TWTs.

DTIC Science & Technology

1981-04-01

comb would be cut from a single piece of copper, probably by a reliable but inexpensive technique such as electroerosion or "chemical milling". All...dimensional. These features would facilitate fabrication by chemical (photo-lithographic) or laser milling as well as by electroerosion with traveling...c, d) has also been implemented since this design should be more robust as well as compatible with electroerosion cutting using a traveling-wire

Millimeter wave generation by relativistic electron beams

NASA Astrophysics Data System (ADS)

Kuo, S. S.; Cheo, B. R.; Tiong, K. K.; Whang, M. H.

1985-11-01

The classical technique of transformation and characteristics is employed to analyze the problem of strong turbulence in unmagnetized plasmas. The effects of resonance broadening and perturbation expansion are treated simultaneously without time securities. The renormalization procedure is used in the transformed Vlasov equation to analyze the turbulence and to derive explicitly a diffusion equation. Analyses are extended to imhomogeneous plasma and the relationship between the transformation and ponderomotive force is obtained.

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.

Developing an ANSI standard for image quality tools for the testing of active millimeter wave imaging systems

NASA Astrophysics Data System (ADS)

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

2017-05-01

In 2016, the millimeter wave (MMW) imaging community initiated the formation of a standard for millimeter wave image quality metrics. This new standard, American National Standards Institute (ANSI) N42.59, will apply to active MMW systems for security screening of humans. The Electromagnetic Signatures of Explosives Laboratory at the Transportation Security Laboratory is supporting the ANSI standards process via the creation of initial prototypes for round-robin testing with MMW imaging system manufacturers and experts. Results obtained for these prototypes will be used to inform the community and lead to consensus objective standards amongst stakeholders. Images collected with laboratory systems are presented along with results of preliminary image analysis. Future directions for object design, data collection and image processing are discussed.

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.

Study on MMW radiation characteristics and imaging of aquatic plants for environmental application

NASA Astrophysics Data System (ADS)

Zhou, Luyan; Zhang, Guangfeng; Liu, Jing

2017-02-01

Working all-day and all-weather, the passive millimeter wave radiometer is widely used in remote sensing, guidance and other fields. In order to solve the increasingly serious problem of water pollution, especially the pollution caused by the rapidly breed of the aquatic plants, a simple and effective method to monitor the water environment is proposed. Aquatic plants can be distinguished through millimeter wave system, as they have high bright temperature compared to Water. The 8mm radiometer is used to measure the radiation characteristics of aquatic plants and image. The simulation results and radiation imaging experiments prove the feasibility and effectively of monitoring aquatic plants by millimeter wave radiometer. This study will contribute to monitoring the aquatic plants growth and decreasing the pollution.

Millimeter- and submillimeter-wave characterization of various fabrics.

PubMed

Dunayevskiy, Ilya; Bortnik, Bartosz; Geary, Kevin; Lombardo, Russell; Jack, Michael; Fetterman, Harold

2007-08-20

Transmission measurements of 14 fabrics are presented in the millimeter-wave and submillimeter-wave electromagnetic regions from 130 GHz to 1.2 THz. Three independent sources and experimental set-ups were used to obtain accurate results over a wide spectral range. Reflectivity, a useful parameter for imaging applications, was also measured for a subset of samples in the submillimeter-wave regime along with polarization sensitivity of the transmitted beam and transmission through doubled layers. All of the measurements were performed in free space. Details of these experimental set-ups along with their respective challenges are presented.

Stimulated Raman scattering of sub-millimeter waves in bismuth

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Tripathi, V. K.

2007-12-01

A high-power sub-millimeter wave propagating through bismuth, a semimetal with non-spherical energy surfaces, parametrically excites a space-charge mode and a back-scattered electromagnetic wave. The free carrier density perturbation associated with the space-charge wave couples with the oscillatory velocity due to the pump to derive the scattered wave. The scattered and pump waves exert a pondermotive force on electrons and holes, driving the space-charge wave. The collisional damping of the decay waves determines the threshold for the parametric instability. The threshold intensity for 20 μm wavelength pump turns out to be ˜2×1012 W/cm2. Above the threshold, the growth rate scales increase with ωo, attain a maximum around ωo=6.5ωp, and, after this, falls off.

LOCATION OF {gamma}-RAY FLARE EMISSION IN THE JET OF THE BL LACERTAE OBJECT OJ287 MORE THAN 14 pc FROM THE CENTRAL ENGINE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agudo, Ivan; Jorstad, Svetlana G.; Marscher, Alan P.

We combine time-dependent multi-waveband flux and linear polarization observations with submilliarcsecond-scale polarimetric images at {lambda} = 7 mm of the BL Lacertae type blazar OJ287 to locate the {gamma}-ray emission in prominent flares in the jet of the source >14 pc from the central engine. We demonstrate a highly significant correlation between the strongest {gamma}-ray and millimeter-wave flares through Monte Carlo simulations. The two reported {gamma}-ray peaks occurred near the beginning of two major millimeter-wave outbursts, each of which is associated with a linear polarization maximum at millimeter wavelengths. Our very long baseline array observations indicate that the two millimeter-wavemore » flares originated in the second of two features in the jet that are separated by >14 pc. The simultaneity of the peak of the higher-amplitude {gamma}-ray flare and the maximum in polarization of the second jet feature implies that the {gamma}-ray and millimeter-wave flares are cospatial and occur >14 pc from the central engine. We also associate two optical flares, accompanied by sharp polarization peaks, with the two {gamma}-ray events. The multi-waveband behavior is most easily explained if the {gamma}-rays arise from synchrotron self-Compton scattering of optical photons from the flares. We propose that flares are triggered by interaction of moving plasma blobs with a standing shock. The {gamma}-ray and optical emission is quenched by inverse Compton losses as synchrotron photons from the newly shocked plasma cross the emission region. The millimeter-wave polarization is high at the onset of a flare, but decreases as the electrons emitting at these wavelengths penetrate less polarized regions.« less

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.

Radar detection of radiation-induced ionization in air

DOEpatents

Gopalsami, Nachappa; Heifetz, Alexander; Chien, Hual-Te; Liao, Shaolin; Koehl, Eugene R.; Raptis, Apostolos C.

2015-07-21

A millimeter wave measurement system has been developed for remote detection of airborne nuclear radiation, based on electromagnetic scattering from radiation-induced ionization in air. Specifically, methods of monitoring radiation-induced ionization of air have been investigated, and the ionized air has been identified as a source of millimeter wave radar reflection, which can be utilized to determine the size and strength of a radiation source.

High-speed microwave photonic switch for millimeter-wave ultra-wideband signal generation.

PubMed

Wang, Li Xian; Li, Wei; Zheng, Jian Yu; Wang, Hui; Liu, Jian Guo; Zhu, Ning Hua

2013-02-15

We propose a scheme for generating millimeter-wave (MMW) ultra-wideband (UWB) signal that is free from low-frequency components and a residual local oscillator. The system consists of two cascaded polarization modulators and is equivalent to a high-speed microwave photonic switch, which truncates a sinusoidal MMW into short pulses. The polarity switchability of the generated MMW-UWB pulse is also demonstrated.

Microwave/millimeter wave technology

NASA Astrophysics Data System (ADS)

Abita, Joseph L.

1988-09-01

The microwave/millimeter-wave monolithic integrated-circuit (MIMIC) technology and systems are discussed along with the application of MIMICs in electronic warfare. The components of a MIMIC are described, with particular attention given to the active-array antenna transmit/receive module, which is at the focus of the MIMIC, and to the features of a typical MIMIC chip. The typical performance characteristics of MIMIC components are presented in tabular form.

Millimeter wave treatment induces apoptosis via activation of the mitochondrial-dependent pathway in human osteosarcoma cells.

PubMed

Wu, Guangwen; Chen, Xuzheng; Peng, Jun; Cai, Qiaoyan; Ye, Jinxia; Xu, Huifeng; Zheng, Chunsong; Li, Xihai; Ye, Hongzhi; Liu, Xianxiang

2012-05-01

Millimeter wave (MW) is an electromagnetic wave with a wavelength between 1 and 10 mm and a frequency of 30-300 GHz that causes multiple biological effects and has been used as a major component in physiotherapies for the clinical treatment of various types of diseases including cancers. However, the precise molecular mechanism of the anticancer activity of millimeter wave remains to be elucidated. In the present study, we investigated the cellular effects of the MW in the U-2OS human osteosarcoma cell line. Our results showed that MW induced cell morphological changes and reduced cell viability in a dose- and time-dependent manner suggesting that MW inhibited the growth of U-2OS cells as demonstrated. Hoechst 33258 staining and Annexin V/propidium iodide double staining exhibited the typical nuclear features of apoptosis and increased the proportion of apoptotic Annexin V-positive cells in a dose-dependent manner, respectively. In addition, MW treatment caused loss of plasma membrane asymmetry, release of cytochrome c, collapse of mitochondrial membrane potential, activation of caspase-9 and -3, and increase of the ratio of pro-apoptotic Bax to anti-apoptotic Bcl-2. Taken together, the results indicate that the U-2OS cell growth inhibitory activity of MW was due to mitochondrial-mediated apoptosis, which may partly explain the anticancer activity of millimeter wave treatment.

Millimeter-wave interconnects for microwave-frequency quantum machines

NASA Astrophysics Data System (ADS)

Pechal, Marek; Safavi-Naeini, Amir H.

2017-10-01

Superconducting microwave circuits form a versatile platform for storing and manipulating quantum information. A major challenge to further scalability is to find approaches for connecting these systems over long distances and at high rates. One approach is to convert the quantum state of a microwave circuit to optical photons that can be transmitted over kilometers at room temperature with little loss. Many proposals for electro-optic conversion between microwave and optics use optical driving of a weak three-wave mixing nonlinearity to convert the frequency of an excitation. Residual absorption of this optical pump leads to heating, which is problematic at cryogenic temperatures. Here we propose an alternative approach where a nonlinear superconducting circuit is driven to interconvert between microwave-frequency (7 ×109 Hz) and millimeter-wave-frequency photons (3 ×1011 Hz). To understand the potential for quantum state conversion between microwave and millimeter-wave photons, we consider the driven four-wave mixing quantum dynamics of nonlinear circuits. In contrast to the linear dynamics of the driven three-wave mixing converters, the proposed four-wave mixing converter has nonlinear decoherence channels that lead to a more complex parameter space of couplings and pump powers that we map out. We consider physical realizations of such converter circuits by deriving theoretically the upper bound on the maximum obtainable nonlinear coupling between any two modes in a lossless circuit, and synthesizing an optimal circuit based on realistic materials that saturates this bound. Our proposed circuit dissipates less than 10-9 times the energy of current electro-optic converters per qubit. Finally, we outline the quantum link budget for optical, microwave, and millimeter-wave connections, showing that our approach is viable for realizing interconnected quantum processors for intracity or quantum data center environments.

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.

System using a megawatt class millimeter wave source and a high-power rectenna to beam power to a suspended platform

DOEpatents

Caplan, Malcolm; Friedman, Herbert W.

2005-07-19

A system for beaming power to a high altitude platform is based upon a high power millimeter gyrotron source, optical transmission components, and a high-power receiving antenna (i.e., a rectenna) capable of rectifying received millimeter energy and converting such energy into useable electrical power.

Overview of High-Resolution Nondestructive Inspection of the Space Shuttle External Tank (ET) Spray-on-Foam Insulation (SOFI) and Acreage Heat tiles using Focused, Synthetic and Holographical Millimeter Wave Techniques

NASA Technical Reports Server (NTRS)

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

2006-01-01

Space Shuttle Columbia's catastrophic failure has been attributed to a piece of spray-on-foam insulation (SOFI) that was dislodged from the external tank (ET) and struck the leading edge of the left wing. A piece of SOFI was also dislodged in the recent Space Shuttle Discovery's flight. From immediately after the Columbia accident, microwave and millimeter wave nondestructive testing methods were considered as potential effective inspection tools for evaluating the integrity of the SOFI. To this end and as a result of these efforts, both real-focused, synthetic focusing and holographical techniques, at a wide range of frequencies covering 24 GHz to 150 GHz, have been developed for this purpose. Images of various complex SOFI panels with a wide range of embedded anomalies (representing real potential defects) have been produced using these techniques, including relatively small anomalies located near complex structural features representative of the external tank. These real-focused and 3D holographical images have effectively demonstrated the utility of these methods for SOFI inspection as being viable, robust, repeatable, simple, portable and relatively inexpensive (tens of $K as opposed to hundreds of $K). In addition, the potential viability of these methods for inspecting acreage heat tiles have has been demonstrated. This paper presents an overview of these activities, representative images of these panels using all of the imaging techniques used and a discussion of the practical attributes of these inspection methods.

Optical generation of millimeter-wave pulses using a fiber Bragg grating in a fiber-optics system.

PubMed

Ye, Qing; Qu, Ronghui; Fang, Zujie

2007-04-10

A scheme is proposed to transform an optical pulse into a millimeter-wave frequency modulation pulse by using a weak fiber Bragg grating (FBG) in a fiber-optics system. The Fourier transformation method is used to obtain the required spectrum response function of the FBG for the Gaussian pulse, soliton pulse, and Lorenz shape pulse. On the condition of the first-order Born approximation of the weak fiber grating, the relation of the refractive index distribution and the spectrum response function of the FBG satisfies the Fourier transformation, and the corresponding refractive index distribution forms are obtained for single-frequency modulation and linear-frequency modulation millimeter-wave pulse generation. The performances of the designed fiber gratings are also studied by a numerical simulation method for a supershort pulse transmission.

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.

Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication.

PubMed

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.

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.

Laboratory measurement of the millimeter wave properties of liquid sulfuric acid (H2SO4). [study of microwave emission from Venus

NASA Technical Reports Server (NTRS)

Fahd, Antoine K.; Steffes, Paul G.

1991-01-01

The methodology and the results of laboratory measurements of the millimeter wave properties of liquid sulfuric acid are presented. Measurements conducted at 30-40 and 90-100 GHz are reported, using different concentrations of liquid H2SO4. The measured data are used to compute the expected opacity of H2SO4 condensates and their effects on the millimeter wave emission from Venus. The cloud condensate is found to have an effect on the emission from Venus. The calculated decrease in brightness temperature is well below the observed decrease in brightness temperature found by de Pater et al. (1991). It is suggested that other constituents such as gaseous H2SO4 also affect the observed variation in the brightness temperature.

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

DTIC Science & Technology

2015-08-19

being the average laser power at angular frequency ω. The constant κ is introduced such that ( )* 20 0 2P E E κ= . The term ( )tφ is the optical...typical link gain equations. Multiplexing techniques, which are not trivial with W-Band modulation, are described. 19-08-2015 Memorandum Office of...1 2 BASIC LINK CONFIGURATIONS………………………………………….……….… 2 3 COMPONENT TECHNOLOGY…………….……………….………..….…………….. 5 4 MULTIPLEXING TECHNIQUES

Evaluation of active and passive near-millimeter-wave radiometric imaging techniques for detection of concealed objects

NASA Astrophysics Data System (ADS)

Reber, E. E.; Foote, F. B.; Schellenbaum, R. L.; Bradley, R. G.

1981-07-01

The potential of radiometric imaging technique to detect shielded nuclear materials and explosives carried covertly by personnel was investigated. This method of detecting contraband depends upon the differences in emissivity and reflectivity of the contraband relative to human tissue. Explosives, unlike metals and metal composites, generally have high emissivities and low reflectivities that closely approximate those of human tissue making explosives difficult to detect. Samples of several common types of explosives (TNT, Detasheet, C4, and several types of water gels) were examined at the 1.4- and 3-mm wavelengths using active and passive radiometeric techniques.

V-band integrated quadriphase modulator

NASA Technical Reports Server (NTRS)

Grote, A.; Chang, K.

1983-01-01

A V-band integrated circuit quadriphase shift keyed modulator/exciter for space communications systems was developed. Intersatellite communications systems require direct modulation at 60 GHz to enhance signal processing capability. For most systems, particularly space applications, small and lightweight components are essential to alleviate severe system design constraints. Thus to achieve wideband, high data rate systems, direct modulation techniques at millimeter waves using solid state integrated circuit technology are an integral part of the overall technology developments.

Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants

PubMed Central

Rodilla, H.; Kim, A. A.; Jeffries, G. D. M.; Vukusic, J.; Jesorka, A.; Stake, J.

2016-01-01

Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz – 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively. PMID:26786983

Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants.

PubMed

Rodilla, H; Kim, A A; Jeffries, G D M; Vukusic, J; Jesorka, A; Stake, J

2016-01-20

Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz - 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively.

The 60 GHz radiometric local vertical sensor experiment

NASA Technical Reports Server (NTRS)

Grauling, C. H., Jr.

1973-01-01

The experiment concept involves the use of millimeter wave radiation the atmospheric oxygen to provide vertical sensing information to a satellite-borne radiometer. The radiance profile studies require the calculation of ray brightness temperature as a function of tangential altitude and atmosphere model, and the computer program developed for this purpose is discussed. Detailed calculations have been made for a total of 12 atmosphere models, including some showing severe warning conditions. The experiment system analysis investigates the effect of various design choices on system behavior. Calculated temperature profiles are presented for a wide variety of frequencies, bandwidths, and atmosphere models. System performance is determined by the convolution of the brightness temperature and an assumed antenna pattern. A compensation scheme to account for different plateau temperatures is developed and demonstrated. The millimeter wave components developed for the local vertical sensor are discussed, with emphasis on the antenna, low noise mixer, and solid state local oscillator. It was concluded that a viable sensing technique exists, useful over a wide range of altitude with an accuracy generally on the order of 0.01 degree or better.

Numerical Analysis of the Performance of Millimeter-Wave RoF-Based Cellular Backhaul Links

NASA Astrophysics Data System (ADS)

Pham, Thu A.; Pham, Hien T. T.; Le, Hai-Chau; Dang, Ngoc T.

2017-08-01

In this paper, we study the performance of a next-generation cellular backhaul network that is based on a hybrid architecture using radio-over-fiber (RoF) and millimeter-wave (MMW) techniques. We develop a mathematic model and comprehensively analyze the performance of a MMW/RoF-based backhaul downlink under the impacts of various physical layer impairments originated from both optical fiber and wireless links. More specifically, the effects of nonlinear distortion, chromatic dispersion, fading, and many types of noises including shot noise, thermal noise, amplifier noise, and relative intensity noise are investigated. The numerical results show that the nonlinear distortion, fiber dispersion, and wireless fading are key factors that limit the system performance. Setting the modulation index properly helps minimize the effect of nonlinear distortion while implementing dispersion shifted optical fibers could be used to reduce the impact of dispersion and as a result, they can improve the bit-error rate. Moreover, it is also verified that, to mitigate the effect of multipath fading, remote radio heads should be located as near the remote antenna units as possible.

Monolithic millimeter-wave diode array beam controllers: Theory and experiment

NASA Technical Reports Server (NTRS)

Sjogren, L. B.; Liu, H.-X. L.; Wang, F.; Liu, T.; Wu, W.; Qin, X.-H.; Chung, E.; Domier, C. W.; Luhmann, N. C., Jr.; Maserjian, J.

1992-01-01

In the current work, multi-function beam control arrays have been fabricated and have successfully demonstrated amplitude control of transmitted beams in the W and D bands (75-170 GHz). While these arrays are designed to provide beam control under DC bias operation, new designs for high-speed electronic and optical control are under development. These arrays will fill a need for high-speed watt-level beam switches in pulsed reflectometer systems under development for magnetic fusion plasma diagnostics. A second experimental accomplishment of the current work is the demonstration in the 100-170 GHz (D band) frequency range of a new technique for the measurement of the transmission phase as well as amplitude. Transmission data can serve as a means to extract ('de-embed') the grid parameters; phase information provides more complete data to assist in this process. Additional functions of the array beam controller yet to be tested include electronically controlled steering and focusing of a reflected beam. These have application in the areas of millimeter-wave electronic scanning radar and reflectometry, respectively.

Simultaneous generation of 40, 80 and 120 GHz optical millimeter-wave from one Mach-Zehnder modulator and demonstration of millimeter-wave transmission and down-conversion

NASA Astrophysics Data System (ADS)

Zhou, Wen; Qin, Chaoyi

2017-09-01

We demonstrate multi-frequency QPSK millimeter-wave (mm-wave) vector signal generation enabled by MZM-based optical carrier suppression (OCS) modulation and in-phase/quadrature (I/Q) modulation. We numerically simulate the generation of 40-, 80- and 120-GHz vector signal. Here, the three different signals carry the same QPSK modulation information. We also experimentally realize 11Gbaud/s QPSK vector signal transmission over 20 km fiber, and the generation of the vector signals at 40-GHz, 80-GHz and 120-GHz. The experimental results show that the bit-error-rate (BER) for all the three different signals can reach the forward-error-correction (FEC) threshold of 3.8×10-3. The advantage of the proposed system is that provide high-speed, high-bandwidth and high-capacity seamless access of TDM and wireless network. These features indicate the important application prospect in wireless access networks for WiMax, Wi-Fi and 5G/LTE.

Photon noise from chaotic and coherent millimeter-wave sources measured with horn-coupled, aluminum lumped-element kinetic inductance detectors

NASA Astrophysics Data System (ADS)

Flanigan, D.; McCarrick, H.; Jones, G.; Johnson, B. R.; Abitbol, M. H.; Ade, P.; Araujo, D.; Bradford, K.; Cantor, R.; Che, G.; Day, P.; Doyle, S.; Kjellstrand, C. B.; Leduc, H.; Limon, M.; Luu, V.; Mauskopf, P.; Miller, A.; Mroczkowski, T.; Tucker, C.; Zmuidzinas, J.

2016-02-01

We report photon-noise limited performance of horn-coupled, aluminum lumped-element kinetic inductance detectors at millimeter wavelengths. The detectors are illuminated by a millimeter-wave source that uses an active multiplier chain to produce radiation between 140 and 160 GHz. We feed the multiplier with either amplified broadband noise or a continuous-wave tone from a microwave signal generator. We demonstrate that the detector response over a 40 dB range of source power is well-described by a simple model that considers the number of quasiparticles. The detector noise-equivalent power (NEP) is dominated by photon noise when the absorbed power is greater than approximately 1 pW, which corresponds to NEP≈2 ×10-17 W Hz-1 /2 , referenced to absorbed power. At higher source power levels, we observe the relationships between noise and power expected from the photon statistics of the source signal: NEP∝P for broadband (chaotic) illumination and NEP∝P1 /2 for continuous-wave (coherent) illumination.

Overview of Millimeter Wave Communications for Fifth-Generation (5G) Wireless Networks—With a Focus on Propagation Models

NASA Astrophysics Data System (ADS)

Rappaport, Theodore S.; Xing, Yunchou; MacCartney, George R.; Molisch, Andreas F.; Mellios, Evangelos; Zhang, Jianhua

2017-12-01

This paper provides an overview of the features of fifth generation (5G) wireless communication systems now being developed for use in the millimeter wave (mmWave) frequency bands. Early results and key concepts of 5G networks are presented, and the channel modeling efforts of many international groups for both licensed and unlicensed applications are described here. Propagation parameters and channel models for understanding mmWave propagation, such as line-of-sight (LOS) probabilities, large-scale path loss, and building penetration loss, as modeled by various standardization bodies, are compared over the 0.5-100 GHz range.

Millimeter Wave Attenuation in Moist Air: Laboratory Measurements and Analysis.

DTIC Science & Technology

1984-03-01

GHz (see Table 1). Artificial aerosol populations of known chemical composition and concentration can be added to study their growth/evaporation... engen in the quantitative deorip im of the inter- (0) Water ion activity ...... .28. 45 action betven, millimeter waves and moist air. The water...sizes. and chemical two states called the saturation point. At saturation, the rate composition. and moat Importantly. having the ability to

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.

Millimeter-Wave Voltage-Controlled Oscillators in 0.13-micrometer CMOS Technology

DTIC Science & Technology

2006-06-01

controlled oscillators. Varactor , transistor, and in- ductor designs are optimized to reduce the parasitic capacitances. An investigation of tradeoff between...quality factor and tuning range for MOS varactors at 24 GHz has shown that the polysilicon gate lengths between 0.18 and 0.24 m result both good...millimeter wave, MOS varactor , quality factor, transmission line, voltage-controlled oscillator (VCO). I. INTRODUCTION WITH THE RAPID advance of high

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.

Concepts for 18/30 GHz satellite communication system, volume 1A: Appendix

NASA Technical Reports Server (NTRS)

Jorasch, R.; Baker, M.; Davies, R.; Cuccia, L.; Mitchell, C.

1979-01-01

The following are appended: (1) Propagation phenomena and attenuation models; (2) Models and measurements of rainfall patterns in the U.S.; (3) Millimeter wave propagation experiments; (4) Comparison of the theory and Millimeter wave propagation experiments; (4) Comparison of theory and experiment; (5) A practical rain attenuation model for CONUS; (6) Space diversity; (7) Values of attenuation for selected U.S. cities; and (8) Additional considerations.

An Airborne Millimeter-Wave FM-CW Radar for Thickness Profiling of Freshwater Ice

DTIC Science & Technology

1992-11-01

commercial and recreational application, including safety and trafficability surveys. A proto- type broadband millimeter wave (26.5 to 40 GHz) Frequency...and utility for ice safety and traffica- appropriate antenna for transmission. Morey (1974) bility studies. Other important applications include...resolution and a 2.7- which can provide reliable safety survey profiling for GHz center frequency, that is capable of airborne pro- the entire practical

High-frequency response to millimeter wave irradiation of YBaCuO thin film and ceramic

NASA Astrophysics Data System (ADS)

Velichko, A. V.; Cherpak, N. T.; Izhyk, E. V.; Kirichenko, A. Ya.; Chukanova, I. N.

1997-02-01

Microwave (35 GHz) and radiowave (9 MHz) responses of an YBaCuO thin film and a ceramic to millimeter (mm) wave irradiation (31.5 GHz) have been studied by means of a quasioptical dielectric resonator with whispering gallery modes and an inductive technique at micro- and radiowaves, respectively. The responses are shown to have a mixed nature including a sufficiently strong non-bolometric component. Relaxation of the surface resistance in time after the irradiation removal obeys the logarithmic law implying the nucleation and flux creep of vortices induced by the irradiation is a mechanism of the response at temperatures 3-10 K below the critical temperature Tc. Dependence of the microwave surface resistance Rsmw on the mm wave pump amplitude Hω is well described by Halbritter's theory of vortex motion inside weak links. A correlation between dependences of the radiowave (rw) response on Hω with that of Rsmw has been found. Thus the mechanism of rw-response is believed to arise from intergranular Josephson couplings. The latter conclusion is further confirmed by a comparison of the pump power dependence of the rw-response with that of conventional DC-response found for granular HTSC in other recent experiments on the response to the subgap radiation.

Josephson junction spectrum analyzer for millimeter and submillimeter wavelengths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larkin, S.Y.; Anischenko, S.E.; Khabayev, P.V.

1994-12-31

A prototype of the Josephson-effect spectrum analyzer developed for the millimeter-wave band is described. The measurement results for spectra obtained in the frequency band from 50 to 250 GHz are presented.

Josephson Junction spectrum analyzer for millimeter and submillimeter wavelengths

NASA Technical Reports Server (NTRS)

Larkin, S. Y.; Anischenko, S. E.; Khabayev, P. V.

1995-01-01

A prototype of the Josephson-effect spectrum analyzer developed for the millimeter wave band is described. The measurement results for spectra obtained in the frequency band from 50 to 250 GHz are presented.

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 polarization and birefringence effects, it was determined that one can not utilize the dielectric properties of powder-containing packages to differentiate hoax attacks and serious security threats.

Transition-Edge Hot-Electron Microbolometers for Millimeter and Submillimeter Astrophysics

NASA Technical Reports Server (NTRS)

Hsieh, Wen-Ting; Stevenson, Thomas; U-yen, Kongpop; Wollack, Edward; Barrentine, Emily

2014-01-01

The millimeter and the submillimeter wavelengths of the electromagnetic spectrum hold a wealth of information about the evolution of the universe. In particular, cosmic microwave background (CMB) radiation and its polarization carry the oldest information in the universe, and provide the best test of the inflationary paradigm available to astronomy today. Detecting gravity waves through their imprint on the CMB polarization would have extraordinary repercussions for cosmology and physics. A transition-edge hot-electron micro - bolometer (THM) consists of a superconducting bilayer transition-edge sensor (TES) with a thin-film absorber. Unlike traditional monolithic bolometers that make use of micromachined structures, the THM em ploys the decoupling between electrons and phonons at millikelvin temperatures to provide thermal isolation. The devices are fabricated photolithographically and are easily integrated with antennas via microstrip transmission lines, and with SQUID (superconducting quantum interference device) readouts. The small volume of the absorber and TES produces a short thermal time constant that facilitates rapid sky scanning. The THM consists of a thin-film metal absorber overlapping a superconducting TES. The absorber forms the termination of a superconducting microstripline that carries RF power from an antenna. The purpose of forming a separate absorber and TES is to allow flexibility in the optimization of the two components. In particular, the absorbing film's impedance can be chosen to match the antenna, while the TES impedance can be chosen to match to the readout SQUID amplifier. This scheme combines the advantages of the TES with the advantages of planar millimeter-wave transmission line circuits. Antenna-coupling to the detectors via planar transmission lines allows the detector dimensions to be much smaller than a wavelength, so the technique can be extended across the entire microwave, millimeter, and submillimeter wavelength ranges. The circuits are fabricated using standard microlithographic techniques and are compatible with uniform, large array formats. Unlike traditional monolithic bolometers that make use of micromachined structures, the THM employs the decoupling between electrons and phonons at millikelvin temperatures to provide thermal isolation. There is no fragile membrane in the structure for thermal isolation, which improves the fabrication yield.

Effects of Variable Spot Size on Human Exposure to 95 GHz Millimeter Wave Energy

DTIC Science & Technology

2017-05-11

AFRL -RH-FS-TR-2017-0017 Effects of Variable Spot Size on Human Exposure to 95-GHz Millimeter Wave Energy James E. Parker Eric J. Nelson...Defense Technical Information Center (DTIC) (http://www.dtic.mil). ( AFRL -RH-FS- - - ) has been reviewed and is approved for publication in accordance with...REPORT NUMBER(S) AFRL -RH-FS-TR-2017-0017 12. DISTRIBUTION / AVAILABILITY STATEMENT Distribution A: Approved for public release; distribution

High-speed millimeter communication through radio-over-free-space-optics network by mode-division multiplexing

NASA Astrophysics Data System (ADS)

Chaudhary, Sushank; Amphawan, Angela

2017-11-01

In an attempt to meet the goal of distributing millimeter-wave (mm-wave) signals, recent years have witnessed significant relevance being given to combining radio frequency with optical fiber technologies. The future of radio-over-free-space-optics technology aims to build a universal platform for distributing millimeter waves for wireless local area networks without using expensive optical fibers. This work is focused on simultaneous transmission of four independent OFDM-based channels, each carrying 20 Gbps to 40 GHz data, by mode-division multiplexing of Laguerre-Gaussian mode with vortex lens and Hermite-Gaussian mode to realize a total transmission of 80 Gbps to 160 GHz data over 50-km free-space optical link. Moreover, the performance of the proposed system is also evaluated under the influence of various atmospheric turbulences, such as light fog, thin fog, and thick fog.

Millimeter Wave Spectrum of the Weakly Bound Complex CH2═CHCN·H2O: Structure, Dynamics, and Implications for Astronomical Search.

PubMed

Calabrese, Camilla; Vigorito, Annalisa; Maris, Assimo; Mariotti, Sergio; Fathi, Pantea; Geppert, Wolf D; Melandri, Sonia

2015-12-03

The weakly bound 1:1 complex between acrylonitrile (CH2═CHCN) and water has been characterized spectroscopically in the millimeter wave range (59.6-74.4 GHz) using a Free Jet Absorption Millimeter Wave spectrometer. Precise values of the rotational and quartic centrifugal distortion constants have been obtained from the measured frequencies of the normal and isotopically substituted water moiety (DOH, DOD, H(18)OH). Structural parameters have been estimated from the rotational constants and their differences among isotopologues: the complex has a planar structure with the two subunits held together by a O-H···N (2.331(3) Å) and a C-H···O (2.508(4) Å) interaction. The ab initio intermolecular binding energy, obtained at the counterpoise corrected MP2/aug-cc-pVTZ level of calculation, is De = 24.4 kJ mol(-1).

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.

Wavelet Fusion for Concealed Object Detection Using Passive Millimeter Wave Sequence Images

NASA Astrophysics Data System (ADS)

Chen, Y.; Pang, L.; Liu, H.; Xu, X.

2018-04-01

PMMW imaging system can create interpretable imagery on the objects concealed under clothing, which gives the great advantage to the security check system. Paper addresses wavelet fusion to detect concealed objects using passive millimeter wave (PMMW) sequence images. According to PMMW real-time imager acquired image characteristics and storage methods firstly, using the sum of squared difference (SSD) as the image-related parameters to screen the sequence images. Secondly, the selected images are optimized using wavelet fusion algorithm. Finally, the concealed objects are detected by mean filter, threshold segmentation and edge detection. The experimental results show that this method improves the detection effect of concealed objects by selecting the most relevant images from PMMW sequence images and using wavelet fusion to enhance the information of the concealed objects. The method can be effectively applied to human body concealed object detection in millimeter wave video.

Low loss millimeter-wave switches based on the Vanadium Dioxide Metal - Insulator - Transition

NASA Astrophysics Data System (ADS)

Field, Mark; Hillman, Christopher; Stupar, Philip; Griffith, Zachary; Rodwell, Mark

2014-03-01

A new ultra-low-loss and broad band millimeter wave switch technology based on the reversible metal / insulator phase transition of vanadium dioxide has been developed. We report having fabricated series configured, single-pole single-throw (SPST) switches having measured S-parameters from DC to 110 GHz. The on-state insertion loss is 0.2 dB and off-state isolation is 21 dB at 50 GHz. The resulting impedance contrast ratio, ZOFF / ZON, is greater than 500:1 at 50 GHz (i.e. cut-off frequency fc ~ 40 THz). As a demonstration of the technology's utility, we also present the results of a 2-bit real time delay phase shifter incorporating a pair of VO2 SP4T switches. This switch technology's high impedance contrast ratio combined with its compactness, ease of integration, and low voltage operation make it an enabler of previously unachievable high-performance millimeter wave FPGAs.

Millimeter wave backscatter measurements in support of collision avoidance applications

NASA Astrophysics Data System (ADS)

Narayanan, Ram M.; Snuttjer, Brett R. J.

1997-11-01

Millimeter-wave short range radar systems have unique advantages in surface navigation applications, such as military vehicle mobility, aircraft landing assistance, and automotive collision avoidance. In collision avoidance applications, characterization of clutter due to terrain and roadside objects is necessary in order to maximize the signal-to-clutter ratio (SCR) and to minimize false alarms. The results of two types of radar cross section (RCS) measurements at 95 GHz are reported in this paper. The first set of measurements presents data on the normalized RCS (NRCS) as well as clutter distributions of various terrain types at low grazing angles of 5° and 7.5°. The second set of measurements presents RCS data and statistics on various types of roadside objects, such as metallic and wooden sign posts. These results are expected to be useful for designers of short-range millimeter-wave collision avoidance radar systems.

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

Overview of Microwave and Millimeter Wave Testing Activities for the Inspection of the Space Shuttle SOH and Heat Tiles

NASA Technical Reports Server (NTRS)

Zoughi, R.

2005-01-01

Microwave and millimeter wave nondestructive testing and evaluation methods, have shown great potential for inspecting the Space Shuttle s external tank spray on foam insulation (SOFI) and acreage heat tiles. These methods are capable of producing high-resolution images of et interior of these structures. To this end, several different microwave and millimeter wave nondestructive testing methods have been investigated for this purpose. These methods have included near-field as well as focused approaches ranging in frequency from 10 GHz to beyond 100 GHz. Additionally, synthetic aperture focusing methods have also been developed in this regime for obtaining high-resolution images of the interior of these critical structures. These methods possess the potential for producing 3D images of these structures in a relatively short amount of time. This paper presents a summary of these activities in addition to providing examples of images produced using these diverse methods.

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.

Propagation Terminal Design and Measurements

NASA Technical Reports Server (NTRS)

Nessel, James

2015-01-01

The NASA propagation terminal has been designed and developed by the Glenn Research Center and is presently deployed at over 5 NASA and partner ground stations worldwide collecting information on the effects of the atmosphere on Ka-band and millimeter wave communications links. This lecture provides an overview of the fundamentals and requirements of the measurement of atmospheric propagation effects and, specifically, the types of hardware and digital signal processing techniques employed by current state-of-the-art propagation terminal systems.

Variable Coupling Scheme for High Frequency Electron Spin Resonance Resonators Using Asymmetric Meshes

PubMed Central

Tipikin, D. S.; Earle, K. A.; Freed, J. H.

2010-01-01

The sensitivity of a high frequency electron spin resonance (ESR) spectrometer depends strongly on the structure used to couple the incident millimeter wave to the sample that generates the ESR signal. Subsequent coupling of the ESR signal to the detection arm of the spectrometer is also a crucial consideration for achieving high spectrometer sensitivity. In previous work, we found that a means for continuously varying the coupling was necessary for attaining high sensitivity reliably and reproducibly. We report here on a novel asymmetric mesh structure that achieves continuously variable coupling by rotating the mesh in its own plane about the millimeter wave transmission line optical axis. We quantify the performance of this device with nitroxide spin-label spectra in both a lossy aqueous solution and a low loss solid state system. These two systems have very different coupling requirements and are representative of the range of coupling achievable with this technique. Lossy systems in particular are a demanding test of the achievable sensitivity and allow us to assess the suitability of this approach for applying high frequency ESR to the study of biological systems at physiological conditions, for example. The variable coupling technique reported on here allows us to readily achieve a factor of ca. 7 improvement in signal to noise at 170 GHz and a factor of ca. 5 at 95 GHz over what has previously been reported for lossy samples. PMID:20458356

Optical-wireless-optical full link for polarization multiplexing quadrature amplitude/phase modulation signal transmission.

PubMed

Li, Xinying; Yu, Jianjun; Chi, Nan; Zhang, Junwen

2013-11-15

We propose and experimentally demonstrate an optical wireless integration system at the Q-band, in which up to 40 Gb/s polarization multiplexing multilevel quadrature amplitude/phase modulation (PM-QAM) signal can be first transmitted over 20 km single-mode fiber-28 (SMF-28), then delivered over a 2 m 2 × 2 multiple-input multiple-output wireless link, and finally transmitted over another 20 km SMF-28. The PM-QAM modulated wireless millimeter-wave (mm-wave) signal at 40 GHz is generated based on the remote heterodyning technique, and demodulated by the radio-frequency transparent photonic technique based on homodyne coherent detection and baseband digital signal processing. The classic constant modulus algorithm equalization is used at the receiver to realize polarization demultiplexing of the PM-QAM signal. For the first time, to the best of our knowledge, we realize the conversion of the PM-QAM modulated wireless mm-wave signal to the optical signal as well as 20 km fiber transmission of the converted optical signal.

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.

Millimeter-wave emissivity as a metric for the non-contact diagnosis of human skin conditions.

PubMed

Owda, Amani Yousef; Salmon, Neil; Harmer, Stuart William; Shylo, Sergiy; Bowring, Nicholas John; Rezgui, Nacer Ddine; Shah, Mamta

2017-10-01

A half-space electromagnetic model of human skin over the band 30-300 GHz was constructed and used to model radiometric emissivity. The model showed that the radiometric emissivity rose from 0.4 to 0.8 over this band, with emission being localized to a layer approximately one millimeter deep in the skin. Simulations of skin with differing water contents associated with psoriasis, eczema, malignancy, and thermal burn wounds indicated radiometry could be used as a non-contact technique to detect and monitor these conditions. The skin emissivity of a sample of 30 healthy volunteers, measured using a 95 GHz radiometer, was found to range from 0.2 to 0.7, and the experimental measurement uncertainty was ±0.002. Men on average were found to have an emissivity 0.046 higher than those of women, a measurement consistent with men having thicker skin than women. The regions of outer wrist and dorsal forearm, where skin is thicker, had emissivities 0.06-0.08 higher than the inner wrist and volar forearms where skin is generally thinner. Recommendations are made to develop a more sophisticated model of the skin and to collect larger data sets to obtain a deeper understanding of the signatures of human skin in the millimeter wave band. Bioelectromagnetics. 38:559-569, 2017. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

Millimeter-wave automotive radars: the markets, technologies, and production costs

NASA Astrophysics Data System (ADS)

Raffaelli, Lamberto; Stewart, Earle

1995-01-01

This paper examines markets, competing technologies, and required production costs of 77 GHz automotive radars. These products will be offered to the market a few years from now and represent the largest opportunity ever offered to the millimeter-wave (MMW) industry. To succeed in this business, an entire industry, primarily focused in the past on expensive small volume military applications, has to be re-engineered to successfully design and manufacture low cost, large volume parts.

Millimeter wave attenuation prediction using a piecewise uniform rain rate model

NASA Technical Reports Server (NTRS)

Persinger, R. R.; Stutzman, W. L.; Bostian, C. W.; Castle, R. E., Jr.

1980-01-01

A piecewise uniform rain rate distribution model is introduced as a quasi-physical model of real rain along earth-space millimeter wave propagation paths. It permits calculation of the total attenuation from specific attenuation in a simple fashion. The model predications are verified by comparison with direct attenuation measurements for several frequencies, elevation angles, and locations. Also, coupled with the Rice-Holmberg rain rate model, attenuation statistics are predicated from rainfall accumulation data.

Survey of key technologies on millimeter-wave CMOS integrated circuits

NASA Astrophysics Data System (ADS)

Yu, Fei; Gao, Lei; Li, Lixiang; Cai, Shuo; Wang, Wei; Wang, Chunhua

2018-05-01

In order to provide guidance for the development of high performance millimeter-wave complementary metal oxide semiconductor (MMW-CMOS) integrated circuits (IC), this paper provides a survey of key technologies on MMW-CMOS IC. Technical background of MMW wireless communications is described. Then the recent development of the critical technologies of the MMW-CMOS IC are introduced in detail and compared. A summarization is given, and the development prospects on MMW-CMOS IC are also discussed.

Project for millimeter and submillimeter-wave devices, and the experimental equipments

NASA Astrophysics Data System (ADS)

Hirose, Nobumitu; Kiyokawa, Masahiro; Matsui, Toshiaki

1995-09-01

A research and development program on millimeter and submillimeter wave devices is described. The facilities provided for this program are also described. In 1994, construction of the clean room was completed. Since then several machines and tools have been installed. We describe some results which have been obtained using these machines and tools. For example, a resist pattern with a 40 nm width on a 400 nm thick polymethylmethacrylate (PMMA) film was obtained.

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. Another important advantage is that, at millimeter wavelengths, the star's brightness poses less of a problem for observers because, while it is still brighter than a planet, the difference in brightness between the two is far less. Because of the physical nature of the objects themselves, protoplanets in different stages of formation could readily be detected by advanced millimeter-wave observatories. The observatories that could provide these advantages are the Millimeter Array (MMA), a proposed 40-antenna millimeter-wave telescope that could be operational by 2005, and an upgraded version of the existing Very Large Array (VLA), a 27-antenna radio telescope in New Mexico. The MMA is a radio telescope designed to operate at wavelengths from 11.5 millimeters down to 0.5 millimeters, or frequencies from 26 to 650 GHz. It will use 40 precision antennas, each 8 meters in diameter, all operating in concert to produce extremely high- resolution images. As is done with the existing VLA and VLBA radio telescopes, the signals from all the MMA antennas will be processed in a special-purpose computer called a correlator. The processing of the signals corrects for atmospheric propagation effects and for the fact that the "synthesized telescope" is in fact made up of individual antennas. Planning for the MMA began as early as 1983, and a number of scientific workshops have allowed U.S. researchers to make known their needs for a millimeter-wave observatory to serve a wide variety of specialties. The National Science Foundation (NSF) provided initial design funding to NRAO in 1995 for MMA studies. Currently, MMA efforts are centered on selecting an appropriate site, which must be very high, dry and flat. A site at 16,500 feet elevation in northern Chile is now being tested. Hawaii's Mauna Kea is also under consideration. If funding is approved for the MMA, the instrument could be in operation by the year 2005. The MMA is expected to be an international instrument, with funding from both U.S. and foreign sources. The MMA will be capable of imaging planetary systems in the earliest stages of their formation. The MMA will be able to detect many more young, low-mass stellar systems and to examine them to determine if they have the disks from which planetary systems are formed. In addition, the MMA could be used to examine the properties of these disks in detail. The properties that could be examined include size, temperature, dust density and chemistry. A number of enhancements have been proposed to the MMA, including longer baselines for greater resolution, the ability to observe at higher frequencies, and greater signal bandwidth. This enhanced MMA would have the sensitivity to directly detect very young giant planets in the nearest star-forming regions, the resolving power to distinguish them from their central stars, and the ability to detect giant planets by measuring their gravitational effect upon their parent stars and thus determine their masses. The VLA, dedicated in 1980, also could contribute to the search for extrasolar planets if proposed upgrades are implemented. Though originally designed to operate at a highest frequency of 24 GHz, the VLA recently has been equipped with receivers for 40-50 GHz. Funding for receivers in this range, at a wavelength of 7 millimeters, was provided in 1993 by the government of Mexico. The VLA now has 13 of its 27 antennas equipped with these 40-50 GHz receivers. Plans for upgrading the VLA include equipping all remaining antennas with such receivers, improving its electronics, and improving its resolution by adding antennas at extended distances. The upgraded VLA will be able to study the inner parts of the dust disks surrounding young stars -- disks that are believed to be the precursors to planetary systems. The inner parts of such disks are obscured at shorter wavelengths. The enhanced VLA will be able to reveal processes occurring in these disks at scales comparable to the size of our own Solar System. "The reason we hope to search for extrasolar planets with millimeter-wave telescopes is that we can build on the experience U.S. astronomers have gained with both millimeter observing and aperture-synthesis telescopes such as the VLA over the past two or three decades," said Brown. He added, "We look forward to applying this expertise to the challenge of answering one of mankind's oldest questions."

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.

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.

Output characteristics of a 0.14 THz dual sheet beam backward wave oscillator based on a hole-grating slow wave structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Xiaopin; Yang, Ziqiang; Shi, Zongjun

A novel backward wave oscillator (BWO) based on a hole-grating slow wave structure is proposed as a dual sheet beam millimeter wave radiation source. In this paper, we focus on the output characteristics of a 0.14 THz hole-grating BWO. The output characteristics of the hole-grating BWO, the conventional single-beam grating BWO, and the dual-beam grating BWO are contrasted in detail. 3-D particle-in-cell results indicate that the hole-grating slow wave structure can help to increase the maximum output power as well as lower the operating current density. Meanwhile, the hole-grating BWO shows good insensitivity to the differences between two sheet electronmore » beams. These characteristics make the hole-grating BWO feasible to be a stable millimeter wave radiation source with higher output power.« less

Multi-Band (K- Q- and E-Band) Multi-Tone Millimeter-Wave Frequency Synthesizer for Radio Wave 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-band 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 K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). These studies would enable the design of robust multi-Gbps data rate space-to-ground satellite communication links. Lastly, the architecture for a compact multi-tone beacon transmitter, which includes a high frequency synthesizer, a polarizer, and a conical horn antenna, has been investigated for a notional CubeSat based space-to-ground radio wave propagation experiment.

Evaluation of quadrature-phase-shift-keying signal characteristics in W-band radio-over-fiber transmission using direct in-phase/quadrature-phase conversion technique

NASA Astrophysics Data System (ADS)

Suzuki, Meisaku; Kanno, Atsushi; Yamamoto, Naokatsu; Sotobayashi, Hideyuki

2016-02-01

The effects of in-phase/quadrature-phase (IQ) imbalances are evaluated with a direct IQ down-converter in the W-band (75-110 GHz). The IQ imbalance of the converter is measured within a range of +/-10 degrees in an intermediate frequency of DC-26.5 GHz. 1-8-G-baud quadrature phase-shift keying (QPSK) signals are transmitted successfully with observed bit error rates within a forward error correction limit of 2×10-3 using radio over fiber (RoF) techniques. The direct down-conversion technique is applicable to next-generation high-speed wireless access communication systems in the millimeter-wave band.

35-45 Giga Hertz Transceiver System for Phase and Magnitude Detection

NASA Technical Reports Server (NTRS)

Beni, Aman Aflaki

2007-01-01

Nondestructive evaluation (NDE) is the science and practice of examining an object in a way that the object's usefulness is not adversely affected. Different types of NDE methods exist but this thesis is based on microwave and millimeter wave NDE using imaging techniques. Microwave NDE is based on illuminating the object under test with a microwave signal and studying the various properties of the reflected signal from the object. This reflected signal contains some information about the inner structure of the object under test. This information may be contained in several parameters including the phase and magnitude of the reflected signal. The goal of this project is to design and build a Q-band coherent transceiver that is capable of measuring the reflected signal's phase and magnitude so that an image of the object under test may be reconstructed. From the several techniques that can be used to construct an image of the object under test, techniques of interest to this work include synthetic aperture focusing technique (SAFT) and microwave holography. The transceiver system should have the ability to sweep a large portion of Q-band frequency range in small frequency steps as quick as possible while the detected phase and magnitude of the reflected signal is very accurate. Several different designs were studied and the final schematic diagram of the transceiver system was determined. One of the most important modules that was designed, implemented and tested in the laboratory was an accurate phase/magnitude detector circuit. The compared results of the scans using the transceiver system and vector network analyzer (VNA) showed that this transceiver system has a great potential to replace a VNA for the purpose of microwave and millimeter wave imaging.

Wireless Data Transmission at Terahertz Carrier Waves Generated from a Hybrid InP-Polymer Dual Tunable DBR Laser Photonic Integrated Circuit.

PubMed

Carpintero, Guillermo; Hisatake, Shintaro; de Felipe, David; Guzman, Robinson; Nagatsuma, Tadao; Keil, Norbert

2018-02-14

We report for the first time the successful wavelength stabilization of two hybrid integrated InP/Polymer DBR lasers through optical injection. The two InP/Polymer DBR lasers are integrated into a photonic integrated circuit, providing an ideal source for millimeter and Terahertz wave generation by optical heterodyne technique. These lasers offer the widest tuning range of the carrier wave demonstrated to date up into the Terahertz range, about 20 nm (2.5 THz) on a single photonic integrated circuit. We demonstrate the application of this source to generate a carrier wave at 330 GHz to establish a wireless data transmission link at a data rate up to 18 Gbit/s. Using a coherent detection scheme we increase the sensitivity by more than 10 dB over direct detection.

First On-Wafer Power Characterization of MMIC Amplifiers at Sub-Millimeter Wave Frequencies

NASA Technical Reports Server (NTRS)

Fung, A. K.; Gaier, T.; Samoska, L.; Deal, W. R.; Radisic, V.; Mei, X. B.; Yoshida, W.; Liu, P. S.; Uyeda, J.; Barsky, M.;

High temperature superconductor analog electronics for millimeter-wavelength communications

NASA Technical Reports Server (NTRS)

Romanofsky, R. R.; Bhasin, K. B.

1991-01-01

The performance of high temperature superconductor (HTS) passive microwave circuits up to X-band was encouraging when compared to their metallic counterparts. The extremely low surface resistance of HTS films up to about 10 GHz enables a reduction in loss by as much as 100 times compared to copper when both materials are kept at about 77 K. However, a superconductor's surface resistance varies in proportion to the frequency squared. Consequently, the potential benefit of HTS materials to millimeter-wave communications requires careful analysis. A simple ring resonator was used to evaluate microstrip losses at Ka-band. Additional promising components were investigated such as antennas and phase shifters. Prospects for HTS to favorable impact millimeter-wave communications systems are discussed.

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.

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. .

Synchro-ballistic recording of detonation phenomena

NASA Astrophysics Data System (ADS)

Critchfield, Robert R.; Asay, Blaine W.; Bdzil, John B.; Davis, William C.; Ferm, Eric N.; Idar, Deanne J.

1997-12-01

Synchro-ballistic use of rotating-mirror streak cameras allows for detailed recording of high-speed events of known velocity and direction. After an introduction to the synchro-ballistic technique, this paper details two diverse applications of the technique as applied in the field of high-explosives research. In the first series of experiments detonation-front shape is recorded as the arriving detonation shock wave tilts an obliquely mounted mirror, causing reflected light to be deflected from the imaging lens. These tests were conducted for the purpose of calibrating and confirming the asymptotic detonation shock dynamics (DSD) theory of Bdzil and Stewart. The phase velocities of the events range from ten to thirty millimeters per microsecond. Optical magnification is set for optimal use of the film's spatial dimension and the phase velocity is adjusted to provide synchronization at the camera's maximum writing speed. Initial calibration of the technique is undertaken using a cylindrical HE geometry over a range of charge diameters and of sufficient length-to- diameter ratio to insure a stable detonation wave. The final experiment utilizes an arc-shaped explosive charge, resulting in an asymmetric denotation-front record. The second series of experiments consists of photographing a shaped-charge jet having a velocity range of two to nine millimeters per microsecond. To accommodate the range of velocities it is necessary to fire several tests, each synchronized to a different section of the jet. The experimental apparatus consists of a vacuum chamber to preclude atmospheric ablation of the jet tip with shocked-argon back lighting to produce a shadow-graph image.

Synchro-ballistic recording of detonation phenomena

DOE Office of Scientific and Technical Information (OSTI.GOV)

Critchfield, R.R.; Asay, B.W.; Bdzil, J.B.

1997-09-01

Synchro-ballistic use of rotating-mirror streak cameras allows for detailed recording of high-speed events of known velocity and direction. After an introduction to the synchro-ballistic technique, this paper details two diverse applications of the technique as applied in the field of high-explosives research. In the first series of experiments detonation-front shape is recorded as the arriving detonation shock wave tilts an obliquely mounted mirror, causing reflected light to be deflected from the imaging lens. These tests were conducted for the purpose of calibrating and confirming the asymptotic Detonation Shock Dynamics (DSD) theory of Bdzil and Stewart. The phase velocities of themore » events range from ten to thirty millimeters per microsecond. Optical magnification is set for optimal use of the film`s spatial dimension and the phase velocity is adjusted to provide synchronization at the camera`s maximum writing speed. Initial calibration of the technique is undertaken using a cylindrical HE geometry over a range of charge diameters and of sufficient length-to-diameter ratio to insure a stable detonation wave. The final experiment utilizes an arc-shaped explosive charge, resulting in an asymmetric detonation-front record. The second series of experiments consists of photographing a shaped-charge jet having a velocity range of two to nine millimeters per microsecond. To accommodate the range of velocities it is necessary to fire several tests, each synchronized to a different section of the jet. The experimental apparatus consists of a vacuum chamber to preclude atmospheric ablation of the jet tip with shocked-argon back lighting to produce a shadow-graph image.« less

A Novel Passive Millimeter Imager for Broad-Area Search - Final Report on Project PL09-NPMI-PD07 (PNNL-55180)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tedeschi, Jonathan R.; Bernacki, Bruce E.; Kelly, James F.

2011-12-31

This report describes research and development efforts toward a novel passive millimeter-wave (mm-wave) electromagnetic imaging device for broad-area search. It addresses the technical challenge of detecting anomalies that occupy a small fraction of a pixel. The purpose of the imager is to pinpoint suspicious locations for cuing subsequent higher-resolution imaging. The technical basis for the approach is to exploit thermal and polarization anomalies that distinguish man-made features from natural features.

Research on the Crystal Growth and Dielectric Properties of High Permittivity Ferroelectric Materials.

DTIC Science & Technology

1984-05-01

decrease in millimeter wave dielectric losses at low temperatures now makes it imperitive to examine the value of dn/dE from liquid nitrogen up to and...and dielectric losses, with both / decreasing at low temperatures down to 77K for the electric field parallel to the polar axis. The observed changes in...xSrxK -vNa Nb501 5 Crystals at RF and Millimeter Wave Frqutncies ................................. 30 APPENDIX 2 Low and High Frequency Dielectric

Small signal amplifiers and converters for millimeter wave Satcom systems

NASA Technical Reports Server (NTRS)

Okean, H. C.

1979-01-01

This paper describes the current state of the art and the various design tradeoffs encompassing the variety of small signal active circuit 'building blocks' deployed in millimeter wave Satcom receivers and transmitters. Included in this catagory are such low noise receiver components as parametric and FET amplifiers and low loss mixer downconverters as well as low level transmitter driver components such as resistive and varactor upconverters. Current and projected state of the art performance data will be presented along with specific examples of operating hardware.

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.

Biological Effects of Millimeter-Wave Irradiation.

DTIC Science & Technology

1982-12-01

With the recent advances in millimeter-wave technology, including the availability of high - power transmitters in this band , the interaction of fields at... power was 14 mW for E- band , 10 mW for U- band ; and the frequency increment was 0.5 GHz. The mean values and the SD for the number of revertant colonies... high stability for short periods (i.e., about 30 minutes). We are now evaluating electronic means of stabilizing the klystron so that a ±1-MHz

Concealed object segmentation and three-dimensional localization with passive millimeter-wave imaging

NASA Astrophysics Data System (ADS)

Yeom, Seokwon

2013-05-01

Millimeter waves imaging draws increasing attention in security applications for weapon detection under clothing. In this paper, concealed object segmentation and three-dimensional localization schemes are reviewed. A concealed object is segmented by the k-means algorithm. A feature-based stereo-matching method estimates the longitudinal distance of the concealed object. The distance is estimated by the discrepancy between the corresponding centers of the segmented objects. Experimental results are provided with the analysis of the depth resolution.

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.

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.

24-71 GHz PCB Array for 5G ISM

NASA Technical Reports Server (NTRS)

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

2017-01-01

Millimeter-wave 5G mobile architectures need to consolidate disparate frequency bands into a single, multifunctional 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 six 5G and ISM bands spanning 24-71 GHz. Importantly, the array is realized using low-cost PCB. The paper presents the design and optimized layout, and discusses fabrication and measurements.

Investigation of Hexagonal Ferrite Film Growth Techniques for Millimeter-Wave Systems Applications.

DTIC Science & Technology

1987-03-15

hexaferrite LPE layer on CoGa 204 substrate. Some areas of the film exhibit a terraced structure .................................... 32 Figure 17 (a) Layer...49 G), which is the standard substrate for yttrium iron garnet epitaxial film growth. The dielectric constant is slightly larger than values for...Details are given ’.- in Appendices III a:d IV. 4.1 INTIODUCTION In LPE , a small lattice mismatch between film and substrate is .r..r ial tc gro.w good

On increasing the spectral efficiency and transmissivity in the data transmission channel on the spacecraft-ground tracking station line

NASA Astrophysics Data System (ADS)

Andrianov, M. N.; Kostenko, V. I.; Likhachev, S. F.

2018-01-01

The algorithms for achieving a practical increase in the rate of data transmission on the space-craft-ground tracking station line has been considered. This increase is achieved by applying spectral-effective modulation techniques, the technology of orthogonal frequency compression of signals using millimeterrange radio waves. The advantages and disadvantages of each of three algorithms have been revealed. A significant advantage of data transmission in the millimeter range has been indicated.

A depolarization and attenuation experiment using the CTS satellite. Volume 1: Experiment description

NASA Technical Reports Server (NTRS)

Bostian, C. W.; Holt, S. B., Jr.; Kauffman, S. R.; Manus, E. A.; Marshall, R. E.; Stutzman, W. L.; Wiley, P. H.

1976-01-01

An experiment for measuring precipitation attenuation and depolarization on the Communications Technology Satellite (CTS) 11.7 GHz downlink is described. Attenuation and depolarization of the signal received from the spacecraft is monitored on a 24 hour basis. Data is correlated with ground weather conditions. Theoretical models for millimeter wave propagation through rain are refined for maximum agreement with observed data. Techniques are developed for predicting and mimimizing the effects of rain scatter and depolarization on future satellite communication systems.

Electronically steerable millimeter wave antenna techniques for space shuttle applications

NASA Technical Reports Server (NTRS)

Kummer, W. H.

1975-01-01

A large multi-function antenna aperture and related components are described which will perform electronic steering of one or more beams for two of the three applications envisioned: (1) communications, (2) radar, and (3) radiometry. The array consists of a 6-meter folded antenna that fits into two pallets. The communications frequencies are 20 and 30 GHz, while the radar is to operate at 13.9 GHz. Weight, prime power, and volumes are given parametrically; antenna designs, electronics configurations, and mechanical design were studied.

Millimeter Waves Techniques Conference (1974) Held on 26-28 March 1974. Volume 2

DTIC Science & Technology

1974-03-01

GHz Coaxial Connector by M. A. Maury, Jr. and W. A. Wambach Maury Microwave Corp. Cucamonga, Cal. 91730 INTRODUCTION A new minature coax connector has...however, accurate joining depends upon such factors as the alignment of bolt holes , paint on the back of the flange that can affect the seating of the...of the locations of pins and holes to a close tolerance is crucial, 3) for low loss requirements a differently designed flange with a rectangular boss

Dielectric millimeter waveguides. Volume 1

NASA Astrophysics Data System (ADS)

Yeh, Cavour

1988-03-01

This report summarizes the result of the research carried out for the Postdoctoral Task E-6-7108 administered by the University of Dayton under contract F30602-81-C-0206 with RADC. The primary objectives of this research program were to learn whether there exists a dielectric waveguide configuration which offers a lower loss figure than a circular dielectric rod and to establish an experimental technique to measure the guiding characteristics of waves on dielectric structures. These objectives were met. Future research areas are also described in this report.

Quasi-Optical Techniques for Millimeter and Submillimeter-Wave Circuits.

DTIC Science & Technology

1981-03-25

permits non-destructive measurement. The cross section of the IS guide is shown in Fig. 4. We create a notch -type grating in the dielectric strip (rl). Then...the e-igenvalue equation is solved. 1he method was modified to minAlyze .a circular patch radiatlng st ructulre. l’ht, prote dtlrc i s essentIalIv...34Hankel transform domain analysis of open circular microstrip radiating structures," IEEE Trans. Antennas and Propagation, Vol. AP-29, Jan. 1981. 19. T

Research in millimeter wave techniques

NASA Technical Reports Server (NTRS)

Mcmillan, R. W.

1977-01-01

The following is investigated; (1) the design of a 183 GHz single ended fundamental mixer to serve as a back up mixer to the subharmonic mixer for airborne applications, (2) attainment of 6 db single sideband conversion loss with the 6 GHz subharmonic mixer model, together with initial tests to determine the feasibility of pumping the mixer at w sub s/4, (3) additional ground based radiometric measurements, and (4) derivation of equations for power transmission of wire grid interferometers, and initial tests to verify these equations.

Precise Millimeter-Wave Laboratory Frequencies for CS and C34S

NASA Astrophysics Data System (ADS)

Gottlieb, C. A.; Myers, P. C.; Thaddeus, P.

2003-05-01

Nine successive rotational lines in the ground vibrational state of CS and C34S between 96 GHz (J=2-1) and 500 GHz (10-9) were measured in the laboratory to an accuracy of a few kHz. When our measurements are combined with the submillimeter-wave measurements of Ahrens & Winnewisser, the entire rotational spectrum of both isotopic species is predicted to an accuracy of about 1 part in 108 up to 500 GHz and 5 parts in 108 near 1000 GHz. These frequencies should be useful for quantitative studies of cloud core collapse and star formation in the millimeter- and submillimeter-wave bands.

Millimeter waves thermally alter the firing rate of the Lymnaea pacemaker neuron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alekseev, S.I.; Kochetkova, N.V.; Ziskin, M.C.

1997-05-01

The effects of millimeter waves (mm-waves, 75 GHz) and temperature elevation on the firing rate of the BP-4 pacemaker neuron of the pond snail Lymnaea stagnalis were studied by using microelectrode techniques. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates (SARs), measured in physiological solution at the radiator outlet, ranged from 600 to 4,200 W/kg, causing temperature rises from 0.3 to 2.2 C, respectively. Irradiation at an SAR of 4,200 W/kg caused a biphasic change in the firing rate, i.e., a transient decrease in the firing rate followedmore » by a gradual increase to a new level that was 68 {+-} 21% above control. The biphasic changes in the firing rate were reproduced by heating under the condition that the magnitude (2 C) and the rate of temperature rise were equal to those produced by the irradiation. The addition of 0.05 mM of ouabain caused the disappearance of transient responses of the neuron to the irradiation. It was shown that the rate of temperature rise played an important role in the development of a transient neuronal response. The threshold stimulus for a transient response of the BP-4 neutron found in warming experiments was a temperature rise of 0.0025 C/s.« less

Millimeter wave transmission studies of YBa2Cu3O7-delta thin films in the 26.5 to 40.0 GHz frequency range

NASA Technical Reports Server (NTRS)

Miranda, F. A.; Gordon, W. L.; Bhasin, K. B.; Heinen, V. O.; Warner, J. D.; Valco, G. J.

1989-01-01

Millimeter wave transmission measurements through YBa2Cu3O(7-delta) thin films on MgO, ZrO2 and LaAlO3 substrates, are reported. The films (approx. 1 micron) were deposited by sequential evaporation and laser ablation techniques. Transition temperatures T sub c, ranging from 89.7 K for the Laser Ablated film on LaAlO3 to approximately 72 K for the sequentially evaporated film on MgO, were obtained. The values of the real and imaginary parts of the complex conductivity, sigma 1 and sigma 2, are obtained from the transmission data, assuming a two fluid model. The BCS approach is used to calculate values for an effective energy gap from the obtained values of sigma sub 1. A range of gap values from 2 DELTA o/K sub B T sub c = 4.19 to 4.35 was obtained. The magnetic penetration depth is evaluated from the deduced values of sigma 2. These results are discussed together with the frequency dependence of the normalized transmission amplitude, P/P sub c, below and above T sub c.

High resolution SAW elastography for ex-vivo porcine skin specimen

NASA Astrophysics Data System (ADS)

Zhou, Kanheng; Feng, Kairui; Wang, Mingkai; Jamera, Tanatswa; Li, Chunhui; Huang, Zhihong

2018-02-01

Surface acoustic wave (SAW) elastography has been proven to be a non-invasive, non-destructive method for accurately characterizing tissue elastic properties. Current SAW elastography technique tracks generated surface acoustic wave impulse point by point which are a few millimeters away. Thus, reconstructed elastography has low lateral resolution. To improve the lateral resolution of current SAW elastography, a new method was proposed in this research. A M-B scan mode, high spatial resolution phase sensitive optical coherence tomography (PhS-OCT) system was employed to track the ultrasonically induced SAW impulse. Ex-vivo porcine skin specimen was tested using this proposed method. A 2D fast Fourier transform based algorithm was applied to process the acquired data for estimating the surface acoustic wave dispersion curve and its corresponding penetration depth. Then, the ex-vivo porcine skin elastogram was established by relating the surface acoustic wave dispersion curve and its corresponding penetration depth. The result from the proposed method shows higher lateral resolution than that from current SAW elastography technique, and the approximated skin elastogram could also distinguish the different layers in the skin specimen, i.e. epidermis, dermis and fat layer. This proposed SAW elastography technique may have a large potential to be widely applied in clinical use for skin disease diagnosis and treatment monitoring.

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.

Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1988-01-01

In the first half of this grant year, laboratory measurements were conducted on the millimeter-wave properties of atmospheric gases under simulated conditions for the outer planet. Significant improvements in the current system have made it possible to accurately characterize the opacity from gaseous NH3 at longer millimeter wavelengths (7 to 10 mm) under simulated Jovian conditions. In the second half of the grant year, it is hoped to extend such measurements to even shorter millimeter-wavelengths. Further analysis and application of the laboratory results to microwave and millimeter-wave absorption data for the outer planets, such as results from Voyager Radio Occultation experiments and earth-based radio astronomical observations will be continued. The analysis of available multispectral microwave opacity data from Venus, including data from the most recent radio astronomical ovservations in the 1.3 to 3.6 cm wavelength range and newly obtained Pioneer-Venus Radio Occulatation measurements at 13 cm, using the laboratory measurements as an interpretative tool will be pursued.

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.

Millimeter-wave MMIC technology for smart weapons

NASA Astrophysics Data System (ADS)

Seashore, Charles R.

1994-12-01

Millimeter wave MMIC component technology has made dramatic progress over the last ten years largely due to funding stimulation received under the ARPA Tri-Service MIMIC program. In several smart weapon systems, MMIC components are now specified as the baseline approach for millimeter wave radar transceiver hardware. Availability of this new frontier in microelectronics has also enabled realization of sensor fusion for multispectral capability to defeat many forms of known countermeasures. The current frequency range for these MMIC-based components is approximately 30 to 100 GHz. In several cases, it has been demonstrated that the MMIC component performance has exceeded that available from hybrid microstrip circuits using selected discrete devices. However, challenges still remain in chip producibility enhancement and cost reduction since many of the essential device structure candidates are themselves emerging technologies with a limited wafer fabrication history and accumulated test databases. It is concluded that smart weapons of the future will rely heavily on advanced microelectronics to satisfy performance requirements as well as meeting stringent packaging and power source constraints.

High Resolution Millimeter Wave Detection of Vertical Cracks in the Space Shuttle External Tank Spray-On-Foam Insulation (SOFI)

NASA Technical Reports Server (NTRS)

Kharkovsky, S.; Zoughi, R.; Hepburn, F.

2006-01-01

Space Shuttle Columbia s catastrophic failure, the separation of a piece of spray-on-foam insulation (SOFI) from the external tank (ET) in the Space Shuttle Discovery s flight in 2005 and crack detected in its ET foam prior to its successful launch in 2006 emphasize the need for effective nondestructive methods for inspecting the shuttle ET SOFI. Millimeter wave nondestructive testing methods have been considered as potential and effective inspection tools for evaluating the integrity of the SOFI. This paper presents recent results of an investigation for the purpose of detecting vertical cracks in SOFI panels using a focused millimeter wave (150 GHz) reflectometer. The presented images of the SOFI panels show the capability of this reflectometer for detecting tight vertical cracks (also as a function of crack opening dimension) in exposed SOFI panels and while covered by a piece of SOFI ramp simulating a more realistic and challenging situation.

Facilities for US Radioastronomy.

ERIC Educational Resources Information Center

Thaddeus, Patrick

1982-01-01

Discusses major developments in radioastronomy since 1945. Topics include proposed facilities, very-long-baseline interferometric array, millimeter-wave telescope, submillimeter-wave telescope, and funding for radioastronomy facilities and projects. (JN)

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.

Infrastructure for the design and fabrication of MEMS for RF/microwave and millimeter wave applications

NASA Astrophysics Data System (ADS)

Nerguizian, Vahe; Rafaf, Mustapha

2004-08-01

This article describes and provides valuable information for companies and universities with strategies to start fabricating MEMS for RF/Microwave and millimeter wave applications. The present work shows the infrastructure developed for RF/Microwave and millimeter wave MEMS platforms, which helps the identification, evaluation and selection of design tools and fabrication foundries taking into account packaging and testing. The selected and implemented simple infrastructure models, based on surface and bulk micromachining, yield inexpensive and innovative approaches for distributed choices of MEMS operating tools. With different educational or industrial institution needs, these models may be modified for specific resource changes using a careful analyzed iteration process. The inputs of the project are evaluation selection criteria and information sources such as financial, technical, availability, accessibility, simplicity, versatility and practical considerations. The outputs of the project are the selection of different MEMS design tools or software (solid modeling, electrostatic/electromagnetic and others, compatible with existing standard RF/Microwave design tools) and different MEMS manufacturing foundries. Typical RF/Microwave and millimeter wave MEMS solutions are introduced on the platform during the evaluation and development phases of the project for the validation of realistic results and operational decision making choices. The encountered challenges during the investigation and the development steps are identified and the dynamic behavior of the infrastructure is emphasized. The inputs (resources) and the outputs (demonstrated solutions) are presented in tables and flow chart mode diagrams.

A dual-mode operation overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic mode output

NASA Astrophysics Data System (ADS)

Bai, Zhen; Zhang, Jun; Zhong, Huihuang

2016-04-01

An overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic (TEM) mode output is designed and presented, by using a kind of coaxial slow wave structure (SWS) with large transversal dimension and small distance between inner and outer conductors. The generator works in dual-mode operation mechanism. The electron beam synchronously interacts with 7π/8 mode of quasi-TEM, at the meanwhile exchanges energy with 3π/8 mode of TM01. The existence of TM01 mode, which is traveling wave, not only increases the beam-wave interaction efficiency but also improves the extraction efficiency. The large transversal dimension of coaxial SWS makes its power capacity higher than that of other reported millimeter-wave devices and the small distance between inner and outer conductors allows only two azimuthally symmetric modes to coexist. The converter after the SWS guarantees the mode purity of output power. Particle-in-cell simulation shows that when the diode voltage is 400 kV and beam current is 3.8 kA, the generation of microwave at 32.26 GHz with an output power of 611 MW and a conversion efficiency of 40% is obtained. The power percentage carried by TEM mode reaches 99.7% in the output power.

A dual-mode operation overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic mode output

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Zhen; Zhang, Jun, E-mail: zhangjun@nudt.edu.cn; Zhong, Huihuang

2016-04-15

An overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic (TEM) mode output is designed and presented, by using a kind of coaxial slow wave structure (SWS) with large transversal dimension and small distance between inner and outer conductors. The generator works in dual-mode operation mechanism. The electron beam synchronously interacts with 7π/8 mode of quasi-TEM, at the meanwhile exchanges energy with 3π/8 mode of TM{sub 01}. The existence of TM{sub 01} mode, which is traveling wave, not only increases the beam-wave interaction efficiency but also improves the extraction efficiency. The large transversal dimension ofmore » coaxial SWS makes its power capacity higher than that of other reported millimeter-wave devices and the small distance between inner and outer conductors allows only two azimuthally symmetric modes to coexist. The converter after the SWS guarantees the mode purity of output power. Particle-in-cell simulation shows that when the diode voltage is 400 kV and beam current is 3.8 kA, the generation of microwave at 32.26 GHz with an output power of 611 MW and a conversion efficiency of 40% is obtained. The power percentage carried by TEM mode reaches 99.7% in the output power.« less

A novel optical millimeter-wave signal generation approach to overcome chromatic dispersion

NASA Astrophysics Data System (ADS)

Liang, Dong; Jiang, Wei; Tan, Qinggui; Zhu, Zhongbo; Liu, Feng

2014-06-01

In this paper, a novel frequency octupling approach for optical millimeter-wave signal generation to overcome chromatic dispersion is proposed and demonstrated. The frequency octupling mm-wave with the baseband signal carried only by -4th order sideband is generated by properly adjusting a series of parameters, which are the modulation constant, the gain of baseband signal, the direct current bias and the different phase of the modulation arms. As the optical millimeter-wave signal is transmitted along the fiber, there is no time shift caused by chromatic dispersion. Theoretical analyses and simulated results show that when the optical mm-wave carrying 2.5 Gbps baseband signal transmits a distance of over 110 km, the eye diagram still keeps open and clear. The power penalty is about 0.4 dB after the optical signal transmits over 40 km. In additions, given the +4th order sideband carries no data, a full-duplex RoF link based on wavelength reuse is built for the uplink. The bidirectional 2.5 Gbps baseband signal could successfully transmit over 40 km with about 0.8 dB power penalty in the simulation. Both theoretical analyses and simulation results show that the full-duplex RoF link has good performance.

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.

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.

A novel time of arrival estimation algorithm using an energy detector receiver in MMW systems

NASA Astrophysics Data System (ADS)

Liang, Xiaolin; Zhang, Hao; Lyu, Tingting; Xiao, Han; Gulliver, T. Aaron

2017-12-01

This paper presents a new time of arrival (TOA) estimation technique using an improved energy detection (ED) receiver based on the empirical mode decomposition (EMD) in an impulse radio (IR) 60 GHz millimeter wave (MMW) system. A threshold is employed via analyzing the characteristics of the received energy values with an extreme learning machine (ELM). The effect of the channel and integration period on the TOA estimation is evaluated. Several well-known ED-based TOA algorithms are used to compare with the proposed technique. It is shown that this ELM-based technique has lower TOA estimation error compared to other approaches and provides robust performance with the IEEE 802.15.3c channel models.

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

Joint NOSC/NRL (Naval Ocean Systems Center/Naval Research Laboratory) InP Microwave/Millimeter Wave Technology Workshop Held in San Diego, California on 25-26 January 1989

DTIC Science & Technology

1989-12-01

A 11A Novel Applications of InP Based Technology: Neurocomputing ........... Aw ru Millimeter-Wave InAlAs/InGaAs/InP Lattice -Matched...Dielectrics) * II-A FLUORIDES (CaF2, BaF2 , SrF2 and their mixtures) e LATTICE MATCH TO MOST IMPORTANT SEMICON- DUCTORS (Slight mismatch can be used for...strained super lattice approach) e COMPARED TO AMORPHOUS DIELECTRICS ORDERED SEMICONDUCTOR-DIELECTRIC INTERFACE (I) Improved carrier transport (high

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.

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.;

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).

An Off-Grid Turbo Channel Estimation Algorithm for Millimeter Wave Communications.

PubMed

Han, Lingyi; Peng, Yuexing; Wang, Peng; Li, Yonghui

2016-09-22

The bandwidth shortage has motivated the exploration of the millimeter wave (mmWave) frequency spectrum for future communication networks. To compensate for the severe propagation attenuation in the mmWave band, massive antenna arrays can be adopted at both the transmitter and receiver to provide large array gains via directional beamforming. To achieve such array gains, channel estimation (CE) with high resolution and low latency is of great importance for mmWave communications. However, classic super-resolution subspace CE methods such as multiple signal classification (MUSIC) and estimation of signal parameters via rotation invariant technique (ESPRIT) cannot be applied here due to RF chain constraints. In this paper, an enhanced CE algorithm is developed for the off-grid problem when quantizing the angles of mmWave channel in the spatial domain where off-grid problem refers to the scenario that angles do not lie on the quantization grids with high probability, and it results in power leakage and severe reduction of the CE performance. A new model is first proposed to formulate the off-grid problem. The new model divides the continuously-distributed angle into a quantized discrete grid part, referred to as the integral grid angle, and an offset part, termed fractional off-grid angle. Accordingly, an iterative off-grid turbo CE (IOTCE) algorithm is proposed to renew and upgrade the CE between the integral grid part and the fractional off-grid part under the Turbo principle. By fully exploiting the sparse structure of mmWave channels, the integral grid part is estimated by a soft-decoding based compressed sensing (CS) method called improved turbo compressed channel sensing (ITCCS). It iteratively updates the soft information between the linear minimum mean square error (LMMSE) estimator and the sparsity combiner. Monte Carlo simulations are presented to evaluate the performance of the proposed method, and the results show that it enhances the angle detection resolution greatly.

Millimeter wave front-end figure of merit, part 2

NASA Astrophysics Data System (ADS)

Silberman, Gabriel G.

1995-09-01

This report presents a practical approach for defining and calculating a meaningful figure of merit for frequency modulated continuous wave radar systems with separate receive and transmit (bistatic) antennas.

Flower elliptical constellation of millimeter-wave radiometers for precipitating cloud monitoring at geostationary scale

NASA Astrophysics Data System (ADS)

Marzano, F. S.; Cimini, D.; Montopoli, M.; Rossi, T.; Mortari, D.; di Michele, S.; Bauer, P.

2009-04-01

Millimeter-wave observation of the atmospheric parameters is becoming an appealing goal within satellite radiometry applications. The major technological advantage of millimeter-wave (MMW) radiometers is the reduced size of the overall system, for given performances, with respect to microwave sensor. On the other hand, millimeter-wave sounding can exploit window frequencies and various gaseous absorption bands at 50/60 GHz, 118 GHz and 183 GHz. These bands can be used to estimate tropospheric temperature profiles, integrated water vapor and cloud liquid content and, using a differentia spectral mode, light rainfall and snowfall. Millimeter-wave radiometers, for given observation conditions, can also exhibit relatively small field-of-views (FOVs), of the order of some kilometers for low-Earth-orbit (LEO) satellites. However, the temporal resolution of LEO millimeter-wave system observations remains a major drawback with respect to the geostationary-Earth-orbit (GEO) satellites. An overpass every about 12 hours for a single LEO platform (conditioned to a sufficiently large swath of the scanning MMW radiometer) is usually too much when compared with the typical temporal scale variation of atmospheric fields. This feature cannot be improved by resorting to GEO platforms due to their high orbit altitude and consequent degradation of the MMW-sensor FOVs. A way to tackle this impasse is to draw our attention at the regional scale and to focus non-circular orbits over the area of interest, exploiting the concept of micro-satellite flower constellations. The Flower Constellations (FCs) is a general class of elliptical orbits which can be optimized, through genetic algorithms, in order to maximize the revisiting time and the orbital height, ensuring also a repeating ground-track. The constellation concept nicely matches the choice of mini-satellites as a baseline choice, due to their small size, weight (less than 500 kilograms) and relatively low cost (essential when deploying several identical speceborne platforms). Moreover, the micro-satellite solution clearly addresses the choice of small passive sensors with small size, low weight and power consumption, features which cannot be usually satisfied by active sensors. In this respect, MMW technology is the most compatible with the specifications and constraints of micro-satellites. In this work, we will discuss the numerical results of a feasibility study aimed at designing a Flower elliptical constellation of 3 micro-satellite millimeter-wave radiometers for pseudo-geostationary atmospheric observations over the Mediterranean region. The Flower constellation will be optimized in such a way to simulate a pseudo-geostationary observation of the Mediterranean area with an observation repetition time less than 2 hours. The mission requirements request the retrieval of thermodinamical and hydrological properties of the troposphere, specifically temperature profiles, integrated water vapor and cloud liquid content, rainfall and snowfall. Several configurations of the MMW radiometer multi-band channels will be discussed, pointing out the trade-off between performances and complexity. Integrated estimation algorithms, based on a Bayesian approache, will be illustrated to retrieve the requested atmospheric parameters, discussing its sensitivity to sensor radiometric precision and accuracy within each frequency-set configuration. After this numerical study, a review of the mission requirements and specifications will be also proposed.

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

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.

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).

A 547 GHz SIS Receiver Employing a Submicron Nb Junction with an Integrated Matching Circuit

NASA Technical Reports Server (NTRS)

Febvre, P.; McGrath, W.; Leduc, H.; Batelaan, P.; Frerking, M.; Hernichel, J.; Bumble, B.

1993-01-01

The most sensitive heterodyne receivers used for millimeter wave and submillimeter wave radioastronomy employ superconductor-insulator-superconductor (SIS) tunnel junctions as the nonlinear mixing element.

Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation

PubMed Central

Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

2016-01-01

Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 106, which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results. PMID:26976363

Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation.

PubMed

Ibrahim, Akram; Férachou, Denis; Sharma, Gargi; Singh, Kanwarpal; Kirouac-Turmel, Marie; Ozaki, Tsuneyuki

2016-03-15

Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 10(6), which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results.

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.

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.

Spiral density waves in a young protoplanetary disk.

PubMed

Pérez, Laura M; Carpenter, John M; Andrews, Sean M; Ricci, Luca; Isella, Andrea; Linz, Hendrik; Sargent, Anneila I; Wilner, David J; Henning, Thomas; Deller, Adam T; Chandler, Claire J; Dullemond, Cornelis P; Lazio, Joseph; Menten, Karl M; Corder, Stuartt A; Storm, Shaye; Testi, Leonardo; Tazzari, Marco; Kwon, Woojin; Calvet, Nuria; Greaves, Jane S; Harris, Robert J; Mundy, Lee G

2016-09-30

Gravitational forces are expected to excite spiral density waves in protoplanetary disks, disks of gas and dust orbiting young stars. However, previous observations that showed spiral structure were not able to probe disk midplanes, where most of the mass is concentrated and where planet formation takes place. Using the Atacama Large Millimeter/submillimeter Array, we detected a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. The arms extend to the disk outer regions and can be traced down to the midplane. These millimeter-wave observations also reveal an emission gap closer to the star than the spiral arms. We argue that the observed spirals trace shocks of spiral density waves in the midplane of this young disk. Copyright © 2016, American Association for the Advancement of Science.

Integrated Millimeter-Wave Frequency Multiplers

NASA Astrophysics Data System (ADS)

Schoenthal, Gerhard S.; Deaver, B. S.; Crowe, T. W.; Bishop, W. L.; Saini, K.; Bradley, R. F.

2001-11-01

Many of the molecules of interest to radio astronomers and atmospheric chemists resonate at frequencies in the millimeter and submillimeter wavelength bands. To measure the spectra of these molecules scientists rely on heterodyne receivers that convert the high frequency signal to the GHz band where it is readily amplified and analyzed. One of the challenges of developing suitable receiver systems is the development of compact, reliable and affordable sources of local oscillator power at frequencies in excess of 100 GHz. One useful solution is to use GaAs Schottky diodes, in their varactor mode, to generate high frequency harmonics of lower frequency sources such as Gunn oscillators. As a part of a multi-national radio astronomy project, the Atacama Millimeter Large Array (ALMA), we have designed and fabricated a broadband frequency tripler with an output centered at 240 GHz. It is integrated on a quartz substrate to greatly reduce the parasitic capacitance and thereby improve electrical performance. The integrated circuit was designed to require no oxides or ohmic contacts, thereby easing fabrication. This talk will discuss the novel millimeter-wave integrated circuit fabrication process and the initial results.

Robust Hybrid Finite Element Methods for Antennas and Microwave Circuits

NASA Technical Reports Server (NTRS)

Gong, J.; Volakis, John L.

1996-01-01

One of the primary goals in this dissertation is concerned with the development of robust hybrid finite element-boundary integral (FE-BI) techniques for modeling and design of conformal antennas of arbitrary shape. Both the finite element and integral equation methods will be first overviewed in this chapter with an emphasis on recently developed hybrid FE-BI methodologies for antennas, microwave and millimeter wave applications. The structure of the dissertation is then outlined. We conclude the chapter with discussions of certain fundamental concepts and methods in electromagnetics, which are important to this study.

It is all about Phase and it is not Star Trek

NASA Astrophysics Data System (ADS)

Field, Robert W.; Grimes, David; Barnum, Timothy J.; Coy, Stephen; Zhou, Yan

2016-06-01

The marriage of chirped pulse millimeter-wave spectroscopy with a buffer gas cooled molecular beam source has yielded an increase in spectral velocity (number of resolution elements per unit time) of a factor of one million! But it gets even better. Essential information is encoded not just in the frequencies of the transitions, but also in the relative intensities and especially phases of the transitions. Transitions between Rydberg states of atoms and molecules are an ideal test ground for techniques that fully exploit these newly accessible observables.

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 invasive electrodes as millimeter waves penetrate skin and bone on the order of 15 mm in depth. Although 50 GHz could not readily penetrate from the outer skull to the center of the cortex, implants on the outer skull or even on the scalp could reach the outer layer of the cerebral cortex where substantial benefit could be realized from such non-contact type excitation.

THz and mm-Wave Sensing of Corneal Tissue Water Content: In Vivo Sensing and Imaging Results

PubMed Central

Taylor, Zachary D.; Garritano, James; Sung, Shijun; Bajwa, Neha; Bennett, David B.; Nowroozi, Bryan; Tewari, Priyamvada; Sayre, James W.; Hubschman, Jean-Pierre; Deng, Sophie X.; Brown, Elliott R.; Grundfest, Warren S.

2015-01-01

A pulsed terahertz (THz) imaging system and millimeter-wave reflectometer were used to acquire images and point measurements, respectively, of five rabbit cornea in vivo. These imaging results are the first ever produced of in vivo cornea. A modified version of a standard protocol using a gentle stream of air and a Mylar window was employed to slightly dehydrate healthy cornea. The sensor data and companion central corneal thickness (CCT) measurements were acquired every 10–15 min over the course of two hours using ultrasound pachymmetry.. Statistically significant positive correlations were established between CCT measurements and millimeter wave reflectivity. Local shifts in reflectivity contrast were observed in the THz imagery; however, the THz reflectivity did not display a significant correlation with thickness in the region probed by the 100 GHz and CCT measurements. This is explained in part by a thickness sensitivity at least 10× higher in the mm-wave than the THz systems. Stratified media and effective media modeling suggest that the protocol perturbed the thickness and not the corneal tissue water content (CTWC). To further explore possible etalon effects, an additional rabbit was euthanized and millimeter wave measurements were obtained during death induced edema. These observations represent the first time that the uncoupled sensing of CTWC and CCT have been achieved in vivo. PMID:26161292

Effect of Al on the microstructure, magnetic and millimeter-wave properties of high oriented barium hexaferrite thin films

NASA Astrophysics Data System (ADS)

Chen, Daming; Chen, Zhuo; Wang, Guijuan; Chen, Yong; Li, Yuanxun; Liu, Yingli

2017-12-01

The microstructure, magnetic and millimeter-wave properties of high oriented barium hexaferrite (BaAlxFe12-xO19) thin films with Al doping level x from 0 to 2 are reported. The films were grown on Pt/TiO2/SiO2/Si substrate by Sol-gel method. It is found that with increasing x from 0 to 2 the hexagonal grain disappear, together with Curie temperature dropped from 449 °C to 332 °C and saturated magnetization (4πMs) decreased from 3.8 kG to 1.9 kG, it is attributed to the fact that the Fe ions were substituted by non-magnetic Al ions, leading to the Fe3+-O-Fe3+ super-exchange interaction became weak. The ferromagnetic resonance (FMR) measurement showed that the FMR linewidths is as low as 113 Oe @ 58 GHz, and the FMR frequency shifted to higher frequency range when increasing Al doping level. These result offer the potential application of barium ferrite thin films in tunable millimeter wave devices such as filter, circulator and isolator.

Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry.

PubMed

McCloy, J S; Sundaram, S K; Matyas, J; Woskov, P P

2011-05-01

Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system, describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. These results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.

Study of transmission line attenuation in broad band millimeter wave frequency range.

PubMed

Pandya, Hitesh Kumar B; Austin, M E; Ellis, R F

2013-10-01

Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

Design of polarizers for a mega-watt long-pulse millimeter-wave transmission line on the large helical device.

PubMed

Ii, T; Kubo, S; Shimozuma, T; Kobayashi, S; Okada, K; Yoshimura, Y; Igami, H; Takahashi, H; Ito, S; Mizuno, Y; Okada, K; Makino, R; Kobayashi, K; Goto, Y; Mutoh, T

2015-02-01

The polarizer is one of the critical components in a high-power millimeter-wave transmission line. It requires full and highly efficient coverage of any polarization states, high-power tolerance, and low-loss feature. Polarizers with rounded shape at the edge of the periodic groove surface are designed and fabricated by the machining process for a mega-watt long-pulse millimeter-wave transmission line of the electron cyclotron resonance heating system in the large helical device. The groove shape of λ/8- and λ/4-type polarizers for an 82.7 GHz transmission line is optimally designed in an integral method developed in the vector theories of diffraction gratings so that the efficiency to realize any polarization state can be maximized. The dependence of the polarization states on the combination of the two polarizer rotation angles (Φλ/8, Φλ/4) is examined experimentally in a low-power test with the newly developed polarization monitor. The results show that the measured polarization characteristics are in good agreement with the calculated ones.

Sources of and Remedies for Removing Unwanted Reflections in Millimeter Wave Images of Complex SOFI-Covered Space Shuttle Structures

NASA Technical Reports Server (NTRS)

Kharkovsky, S.; Zoughi, R.; Hepburn, Frank L.

2007-01-01

In the recent years, continuous-wave near-field and lens-focused millimeter wave imaging systems have been effectively used to demonstrate their utility for producing high-resolution images of metallic structures covered with spay on foam insulation (SOFI) such as the Space Shuttle external fuel tank. However, for some specific structures a certain interference -pattern may be superimposed on the produced images. There are methods by which the influence of this unwanted interference can be reduced, such as the incorporation of an incidence .angle and the proper use of signal polarization. This paper presents the basics of this problem and describes the use of the methods for reducing this unwanted influence through specific examples.

Synthesis of structures of electric small-sized radiators using impedance matching materials for millimeter waves

NASA Astrophysics Data System (ADS)

Klimov, Konstantin N.; Epaneshnikova, Irina K.; Belevtsev, Andrey M.; Godin, Andrey S.; Drize, Artemiy D.

2017-10-01

The usage of impedance matching materials for millimeters waves in antenna systems is a promising direction in the development of modern radar stations that allows unifying nomenclature of radiating elements. One of possible appliances of impedance matching materials is transfer of working frequencies of radiating elements to bands with greater wavelength. The usage of several impedance matching mediums, for example, with ɛr=μr=2, ɛr=μr=4, ɛr=μr=8, ɛr=μr=10 allows to extend waveband of the radiating element by 2, 4, 8 and 10 times.

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.

A Practical Millimeter-Wave Holographic Imaging System with Tunable IF Attenuator

NASA Astrophysics Data System (ADS)

Zhu, Yu-Kun; Yang, Ming-Hui; Wu, Liang; Sun, Yun; Sun, Xiao-Wei

2017-10-01

A practical millimeter-wave (mmw) holographic imaging system with tunable intermediate frequency (IF) attenuator has been developed. It can be used for the detection of concealed weapons at security checkpoints, especially the airport. The system is utilized to scan the passenger and detect the weapons hidden in the clothes. To reconstruct the three dimensions (3-D) image, a holographic mmw imaging algorithm based on aperture synthesis and back scattering is presented. The system is active and works at 28-33 GHz. Tunable IF attenuator is applied to compensate the intensity and phase differences between multi-channels and multi-frequencies.

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.

InP-based millimeter-wave PIN diodes for switching and phase-shifting application

NASA Astrophysics Data System (ADS)

Pavlidis, Dimitris; Alekseev, Egor; Hong, Kyushik; Cui, Delong

1997-10-01

InP-based PIN design, technology and circuit implementation were addressed and successfully applied to millimeter-wave MMIC switches and phase shifters. A wet etchant based via technology was developed and applied to InP MMIC fabrication. MOCVD and MBE material growth was used for PIN realization and PIN specific growth optimization is discussed. Experimentally determined electrical characteristics and good performance is presented for a variety of InP-based PIN MMICs including coplanar and microstrip Ka-band SPST switches, W-band microstrip SPST switches and a 90-degree phase shifter.

Application of reflectometry power flow for magnetic field pitch angle measurements in tokamak plasmas (invited).

PubMed

Gourdain, P-A; Peebles, W A

2008-10-01

Reflectometry has successfully demonstrated measurements of many important parameters in high temperature tokamak fusion plasmas. However, implementing such capabilities in a high-field, large plasma, such as ITER, will be a significant challenge. In ITER, the ratio of plasma size (meters) to the required reflectometry source wavelength (millimeters) is significantly larger than in existing fusion experiments. This suggests that the flow of the launched reflectometer millimeter-wave power can be realistically analyzed using three-dimensional ray tracing techniques. The analytical and numerical studies presented will highlight the fact that the group velocity (or power flow) of the launched microwaves is dependent on the direction of wave propagation relative to the internal magnetic field. It is shown that this dependence strongly modifies power flow near the cutoff layer in a manner that embeds the local magnetic field direction in the "footprint" of the power returned toward the launch antenna. It will be shown that this can potentially be utilized to locally determine the magnetic field pitch angle at the cutoff location. The resultant beam drift and distortion due to magnetic field and relativistic effects also have significant consequences on the design of reflectometry systems for large, high-field fusion experiments. These effects are discussed in the context of the upcoming ITER burning plasma experiment.

Low-cost three-dimensional millimeter-wave holographic imaging system based on a frequency-scanning antenna.

PubMed

Amin Nili, Vahid; Mansouri, Ehsan; Kavehvash, Zahra; Fakharzadeh, Mohammad; Shabany, Mahdi; Khavasi, Amin

2018-01-01

In this paper, a closed-form two-dimensional reconstruction technique for hybrid frequency and mechanical scanning millimeter-wave (MMW) imaging systems is proposed. Although being commercially implemented in many imaging systems as a low-cost real-time solution, the results of frequency scanning systems have been reconstructed numerically or have been reported as the captured raw data with no clear details. Furthermore, this paper proposes a new framework to utilize the captured data of different frequencies for three-dimensional (3D) reconstruction based on novel proposed closed-form relations. The hybrid frequency and mechanical scanning structure, together with the proposed reconstruction method, yields a low-cost MMW imaging system with a satisfying performance. The extracted reconstruction formulations are validated through numerical simulations, which show comparable image quality with conventional MMW imaging systems, i.e., switched-array (SA) and phased-array (PA) structures. Extensive simulations are also performed in the presence of additive noise, demonstrating the acceptable robustness of the system against system noise compared to SA and comparable performance with PA. Finally, 3D reconstruction of the simulated data shows a depth resolution of better than 10 cm with minimum degradation of lateral resolution in the 10 GHz frequency bandwidth.

Millimeter waves or extremely high frequency electromagnetic fields in the environment: what are their effects on bacteria?

PubMed

Soghomonyan, Diana; Trchounian, Karen; Trchounian, Armen

2016-06-01

Millimeter waves (MMW) or electromagnetic fields of extremely high frequencies at low intensity is a new environmental factor, the level of which is increased as technology advance. It is of interest that bacteria and other cells might communicate with each other by electromagnetic field of sub-extremely high frequency range. These MMW affected Escherichia coli and many other bacteria, mainly depressing their growth and changing properties and activity. These effects were non-thermal and depended on different factors. The significant cellular targets for MMW effects could be water, cell plasma membrane, and genome. The model for the MMW interaction with bacteria is suggested; a role of the membrane-associated proton FOF1-ATPase, key enzyme of bioenergetic relevance, is proposed. The consequences of MMW interaction with bacteria are the changes in their sensitivity to different biologically active chemicals, including antibiotics. Novel data on MMW effects on bacteria and their sensitivity to different antibiotics are presented and discussed; the combined action of MMW and antibiotics resulted with more strong effects. These effects are of significance for understanding changed metabolic pathways and distinguish role of bacteria in environment; they might be leading to antibiotic resistance in bacteria. The effects might have applications in the development of technique, therapeutic practices, and food protection technology.

The Extended Parabolic Equation Method and Implication of Results for Atmospheric Millimeter-Wave and Optical Propagation

NASA Technical Reports Server (NTRS)

Manning, Robert M.

2004-01-01

The extended wide-angle parabolic wave equation applied to electromagnetic wave propagation in random media is considered. A general operator equation is derived which gives the statistical moments of an electric field of a propagating wave. This expression is used to obtain the first and second order moments of the wave field and solutions are found that transcend those which incorporate the full paraxial approximation at the outset. Although these equations can be applied to any propagation scenario that satisfies the conditions of application of the extended parabolic wave equation, the example of propagation through atmospheric turbulence is used. It is shown that in the case of atmospheric wave propagation and under the Markov approximation (i.e., the -correlation of the fluctuations in the direction of propagation), the usual parabolic equation in the paraxial approximation is accurate even at millimeter wavelengths. The methodology developed here can be applied to any qualifying situation involving random propagation through turbid or plasma environments that can be represented by a spectral density of permittivity fluctuations.

Enhanced traveling wave amplification of co-planar slow wave structure by extended phase-matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palm, Andrew; Sirigiri, Jagadishwar; Shin, Young-Min, E-mail: yshin@niu.edu

2015-09-15

The electron beam co-propagating with slow waves in a staggered double grating array (SDGA) efficiently amplifies millimeter and sub-millimeter waves over a wide spectrum. Our theoretical and numerical analyses show that the power amplification in the fundamental passband is enhanced by the extended beam-wave phase-matching. Particle-in-cell simulations on the SDGA slow wave structure, designed with 10.4 keV and 50–100 mA sheet beam, indicate that maintaining beam-wave synchronization along the entire length of the circuit improves the gain by 7.3% leading to a total gain of 28 dB, corresponding to 62 W saturated power at the middle of operating band, and a 3-dB bandwidthmore » of 7 GHz with 10.5% at V-band (73.5 GHz center frequency) with saturated peak power reaching 80 W and 28 dB at 71 GHz. These results also show a reasonably good agreement with analytic calculations based on Pierce small signal gain theory.« less

Millimeter Wave and Terahertz Synthetic Aperture Radar for Locating Metallic Scatterers Embedded in Scattering Media

NASA Astrophysics Data System (ADS)

Richard, Jonathan T.; Everitt, Henry O.

2017-11-01

A rail-mounted synthetic aperture radar has been constructed to operate at W-band (75 - 110 GHz) and a THz band (325 - 500 GHz) in order to ascertain its ability to locate isolated small, visually obscured metallic scatterers embedded in highly scattering dielectric hosts that are either semi-transparent or opaque. A top view 2D algorithm was used to reconstruct scenes from the acquired data, locating metallic scatterers at W-band with high range and cross-range resolution of 4.3 and 2 mm, respectively, and with improved range resolution of 0.86 mm at the THz band. Millimeter-sized metallic scatterers were easily located when embedded in semi-transparent, highly scattering target hosts of Styrofoam and waxy packing foam but were more difficult to locate when embedded in relatively opaque, highly scattering Celotex panels. Although the THz band provided the expected greater spatial resolution, it required the target to be moved closer to the rail and had a more limited field of view that prevented some targets from being identified. Techniques for improving the signal to noise ratio are discussed. This work establishes a path for developing techniques to render a complete 3D reconstruction of a scene.

The AzTEC millimeter-wave camera: Design, integration, performance, and the characterization of the (sub-)millimeter galaxy population

NASA Astrophysics Data System (ADS)

Austermann, Jason Edward

One of the primary drivers in the development of large format millimeter detector arrays is the study of sub-millimeter galaxies (SMGs) - a population of very luminous high-redshift dust-obscured starbursts that are widely believed to be the dominant contributor to the Far-Infrared Background (FIB). The characterization of such a population requires the ability to map large patches of the (sub-)millimeter sky to high sensitivity within a feasible amount of time. I present this dissertation on the design, integration, and characterization of the 144-pixel AzTEC millimeter-wave camera and its application to the study of the sub-millimeter galaxy population. In particular, I present an unprecedented characterization of the "blank-field" (fields with no known mass bias) SMG number counts by mapping over 0.5 deg^2 to 1.1mm depths of ~1mJy - a previously unattained depth on these scales. This survey provides the tightest SMG number counts available, particularly for the brightest and rarest SMGs that require large survey areas for a significant number of detections. These counts are compared to the predictions of various models of the evolving mm/sub-mm source population, providing important constraints for the ongoing refinement of semi-analytic and hydrodynamical models of galaxy formation. I also present the results of an AzTEC 0.15 deg^2 survey of the COSMOS field, which uncovers a significant over-density of bright SMGs that are spatially correlated to foreground mass structures, presumably as a result of gravitational lensing. Finally, I compare the results of the available SMG surveys completed to date and explore the effects of cosmic variance on the interpretation of individual surveys.

Development of 2-D horn-antenna millimeter-wave imaging device (HMID) for the plasma diagnostics

NASA Astrophysics Data System (ADS)

Nagayama, Y.; Ito, N.; Kuwahara, D.; Tsuchiya, H.; Yamaguchi, S.

2017-04-01

The two-dimensional (2-D) Horn-antenna Millimeter-wave Imaging Device (HMID) has been developed for the O-mode Microwave Imaging Reflectometry (O-MIR) in the Large Helical Device (LHD). The detectable frequency range of the HMID is 23-33 GHz, which corresponds to the cutoff electron density of 0.8-1.5 × 1019 m-3 in the O-MIR. The HMID is a 2-D imaging device that improves on the horn-antenna mixer array, which had been developed for the X-mode MIR in the LHD. In the HMID, the signal (RF) wave from the horn antenna is transmitted to the microstrip line by the finline transmitter, and this is mixed by the double-balanced-mixer with the local oscillation wave that is fed by a coaxial cable. By using the HMID, the MIR optical system can be significantly simplified.

Development of 2-D horn-antenna millimeter-wave imaging device (HMID) for the plasma diagnostics.

PubMed

Nagayama, Y; Ito, N; Kuwahara, D; Tsuchiya, H; Yamaguchi, S

2017-04-01

The two-dimensional (2-D) Horn-antenna Millimeter-wave Imaging Device (HMID) has been developed for the O-mode Microwave Imaging Reflectometry (O-MIR) in the Large Helical Device (LHD). The detectable frequency range of the HMID is 23-33 GHz, which corresponds to the cutoff electron density of 0.8-1.5 × 10 19 m -3 in the O-MIR. The HMID is a 2-D imaging device that improves on the horn-antenna mixer array, which had been developed for the X-mode MIR in the LHD. In the HMID, the signal (RF) wave from the horn antenna is transmitted to the microstrip line by the finline transmitter, and this is mixed by the double-balanced-mixer with the local oscillation wave that is fed by a coaxial cable. By using the HMID, the MIR optical system can be significantly simplified.

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

Fully Polarimetric Passive W-band Millimeter Wave Imager for Wide Area Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tedeschi, Jonathan R.; Bernacki, Bruce E.; Sheen, David M.

2013-09-27

We describe the design and phenomenology imaging results of a fully polarimetric W-band millimeter wave (MMW) radiometer developed by Pacific Northwest National Laboratory for wide-area search. Operating from 92 - 94 GHz, the W-band radiometer employs a Dicke switching heterodyne design isolating the horizontal and vertical mm-wave components with 40 dB of polarization isolation. Design results are presented for both infinite conjugate off-axis parabolic and finite conjugate off-axis elliptical fore-optics using optical ray tracing and diffraction calculations. The received linear polarizations are down-converted to a microwave frequency band and recombined in a phase-shifting network to produce all six orthogonal polarizationmore » states of light simultaneously, which are used to calculate the Stokes parameters for display and analysis. The resulting system performance produces a heterodyne receiver noise equivalent delta temperature (NEDT) of less than 150m Kelvin. The radiometer provides novel imaging capability by producing all four of the Stokes parameters of light, which are used to create imagery based on the polarization states associated with unique scattering geometries and their interaction with the down welling MMW energy. The polarization states can be exploited in such a way that man-made objects can be located and highlighted in a cluttered scene using methods such as image comparison, color encoding of Stokes parameters, multivariate image analysis, and image fusion with visible and infrared imagery. We also present initial results using a differential imaging approach used to highlight polarization features and reduce common-mode noise. Persistent monitoring of a scene using the polarimetric passive mm-wave technique shows great promise for anomaly detection caused by human activity.« less

A Millimeter-Wave Digital Link for Wireless MRI

PubMed Central

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

2017-01-01

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. PMID:27810803

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.

Pre-coding assisted generation of a frequency quadrupled optical vector D-band millimeter wave with one Mach-Zehnder modulator.

PubMed

Zhou, Wen; Li, Xinying; Yu, Jianjun

2017-10-30

We propose QPSK millimeter-wave (mm-wave) vector signal generation for D-band based on balanced precoding-assisted photonic frequency quadrupling technology employing a single intensity modulator without an optical filter. The intensity MZM is driven by a balanced pre-coding 37-GHz QPSK RF signal. The modulated optical subcarriers are directly sent into the single ended photodiode to generate 148-GHz QPSK vector signal. We experimentally demonstrate 1-Gbaud 148-GHz QPSK mm-wave vector signal generation, and investigate the bit-error-rate (BER) performance of the vector signals at 148-GHz. The experimental results show that the BER value can be achieved as low as 1.448 × 10 -3 when the optical power into photodiode is 8.8dBm. To the best of our knowledge, it is the first time to realize the frequency-quadrupling vector mm-wave signal generation at D-band based on only one MZM without an optical filter.

Computer-Aided Design of Low-Noise Microwave Circuits

NASA Astrophysics Data System (ADS)

Wedge, Scott William

1991-02-01

Devoid of most natural and manmade noise, microwave frequencies have detection sensitivities limited by internally generated receiver noise. Low-noise amplifiers are therefore critical components in radio astronomical antennas, communications links, radar systems, and even home satellite dishes. A general technique to accurately predict the noise performance of microwave circuits has been lacking. Current noise analysis methods have been limited to specific circuit topologies or neglect correlation, a strong effect in microwave devices. Presented here are generalized methods, developed for computer-aided design implementation, for the analysis of linear noisy microwave circuits comprised of arbitrarily interconnected components. Included are descriptions of efficient algorithms for the simultaneous analysis of noisy and deterministic circuit parameters based on a wave variable approach. The methods are therefore particularly suited to microwave and millimeter-wave circuits. Noise contributions from lossy passive components and active components with electronic noise are considered. Also presented is a new technique for the measurement of device noise characteristics that offers several advantages over current measurement methods.

Interferometric synthetic aperture radar: Building tomorrow's tools today

USGS Publications Warehouse

Lu, Zhong

2006-01-01

A synthetic aperture radar (SAR) system transmits electromagnetic (EM) waves at a wavelength that can range from a few millimeters to tens of centimeters. The radar wave propagates through the atmosphere and interacts with the Earth’s surface. Part of the energy is reflected back to the SAR system and recorded. Using a sophisticated image processing technique, called SAR processing (Curlander and McDonough, 1991), both the intensity and phase of the reflected (or backscattered) signal of each ground resolution element (a few meters to tens of meters) can be calculated in the form of a complex-valued SAR image representing the reflectivity of the ground surface. The amplitude or intensity of the SAR image is determined primarily by terrain slope, surface roughness, and dielectric constants, whereas the phase of the SAR image is determined primarily by the distance between the satellite antenna and the ground targets, slowing of the signal by the atmosphere, and the interaction of EM waves with ground surface. Interferometric SAR (InSAR) imaging, a recently developed remote sensing technique, utilizes the interaction of EM waves, referred to as interference, to measure precise distances. Very simply, InSAR involves the use of two or more SAR images of the same area to extract landscape topography and its deformation patterns.

Millimeter transient point sources in the SPTpol 100 square degree survey

DOE PAGES

Whitehorn, N.; Natoli, T.; Ade, P. A. R.; ...

2016-10-18

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg 2 patch of sky centered atmore » R.A. 23 h30 m and decl. –55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. As a result, one candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low (p = 0.01) to confirm detection.« less

MILLIMETER TRANSIENT POINT SOURCES IN THE SPTpol 100 SQUARE DEGREE SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitehorn, N.; Haan, T. de; George, E. M.

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg{sup 2} patch of sky centered atmore » R.A. 23{sup h}30{sup m} and decl. −55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. One candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low ( p = 0.01) to confirm detection.« less

Millimeter transient point sources in the SPTpol 100 square degree survey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitehorn, N.; Natoli, T.; Ade, P. A. R.

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg 2 patch of sky centered atmore » R.A. 23 h30 m and decl. –55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. As a result, one candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low (p = 0.01) to confirm detection.« less

The Millimeter Sky Transparency Imager (MiSTI)

NASA Astrophysics Data System (ADS)

Tamura, Yoichi; Kawabe, Ryohei; Kohno, Kotaro; Fukuhara, Masayuki; Momose, Munetake; Ezawa, Hajime; Kuboi, Akihito; Sekiguchi, Tomohiko; Kamazaki, Takeshi; Vila-Vilaró, Baltasar; Nakagawa, Yuki; Okada, Norio

2011-04-01

The Millimeter Sky Transparency Imager (MiSTI) is a small millimeter-wave scanning telescope with a 25-cm diameter dish operating at 183 GHz. MiSTI is installed at Atacama, Chile, and it measures emission from atmospheric water vapor and its fluctuations to estimate atmospheric absorption in the millimeter to submillimeter range. MiSTI observes the water vapor distribution at a spatial resolution of 0.°5, and it is sensitive enough to detect an excess path length of lesssim0.05 mm for an integration time of 1 s. By comparing the MiSTI measurements with those by a 220 GHz tipper, we validated that the 183 GHz measurements of MiSTI are correct, down to the level of any residual systematic errors in the 220 GHz measurements. Since 2008, MiSTI has provided real-time (every 1 hr) monitoring of the all-sky opacity distribution and atmospheric transmission curves in the (sub)millimeter through the internet, allowing us to know the (sub)millimeter sky conditions at Atacama.

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.

Mode-locked laser with pulse interleavers in a monolithic photonic integrated circuit for millimeter wave and terahertz carrier generation.

PubMed

Lo, Mu-Chieh; Guzmán, Robinson; Gordón, Carlos; Carpintero, Guillermo

2017-04-15

This Letter presents a photonics-based millimeter wave and terahertz frequency synthesizer using a monolithic InP photonic integrated circuit composed of a mode-locked laser (MLL) and two pulse interleaver stages to multiply the repetition rate frequency. The MLL is a multiple colliding pulse MLL producing an 80 GHz repetition rate pulse train. Through two consecutive monolithic pulse interleaver structures, each doubling the repetition rate, we demonstrate the achievement of 160 and 320 GHz. The fabrication was done on a multi-project wafer run of a generic InP photonic technology platform.

Passive Fully Polarimetric W-Band Millimeter-Wave Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernacki, Bruce E.; Kelly, James F.; Sheen, David M.

2012-04-01

We present the theory, design, and experimental results obtained from a scanning passive W-band fully polarimetric imager. Passive millimeter-wave imaging offers persistent day/nighttime imaging and the ability to penetrate dust, clouds and other obscurants, including clothing and dry soil. The single-pixel scanning imager includes both far-field and near-field fore-optics for investigation of polarization phenomena. Using both fore-optics, a variety of scenes including natural and man-made objects was imaged and these results are presented showing the utility of polarimetric imaging for anomaly detection. Analysis includes conventional Stokes-parameter based approaches as well as multivariate image analysis methods.

92 GHz dual-polarized integrated horn antennas

NASA Technical Reports Server (NTRS)

Ali-Ahmad, Walid Y.; Rebeiz, Gabriel M.

1991-01-01

A dual-polarized two-dimensional imaging array was designed for millimeter-wave applications. The dual-polarized design consists of two dipoles perpendicular to each other and suspended on the same membrane inside a pyramidal cavity etched in silicon. The dual-polarized antenna is fully monolithic with room available for processing electronics. The IF or video signals are taken out through a novel bias and feeding structure. The measured polarization isolation is better than 20 dB at 92 GHz, and the orthogonal channels show identical far-field patterns. The antenna is well suited for millimeter-wave polarimetric synthetic-aperture radars (SARs) and high-efficiency balanced-mixer receivers.

Doped-channel heterojunction structures for millimeter-wave discrete devices and MMICs

NASA Technical Reports Server (NTRS)

Saunier, P.; Kao, Y. C.; Khatibzadeh, A. M.; Tserng, H. Q.; Bradshaw, K.

1989-01-01

AlGaAs/InGaAs/GaAs-type heterostructures with one or two channels have been used to fabricate both discrete devices and monolithic amplifiers for millimeter-wave operation. The authors report that 0.25-micron x 50-micron discrete devices delivered a power density of 1 W/mm with 2.9-dB gain and 25 percent efficiency at 60 GHz. A 100-micron monolithic single-stage amplifier demonstrated a record 40 percent efficiency at 32 GHz, and a two-stage monolithic amplifier achieved a record 31.3 percent efficiency with 72-mW power and 13-dB gain at 32 GHz.

Optoelectronic cross-injection locking of a dual-wavelength photonic integrated circuit for low-phase-noise millimeter-wave generation.

PubMed

Kervella, Gaël; Van Dijk, Frederic; Pillet, Grégoire; Lamponi, Marco; Chtioui, Mourad; Morvan, Loïc; Alouini, Mehdi

2015-08-01

We report on the stabilization of a 90-GHz millimeter-wave signal generated from a fully integrated photonic circuit. The chip consists of two DFB single-mode lasers whose optical signals are combined on a fast photodiode to generate a largely tunable heterodyne beat note. We generate an optical comb from each laser with a microwave synthesizer, and by self-injecting the resulting signal, we mutually correlate the phase noise of each DFB and stabilize the beatnote on a multiple of the frequency delivered by the synthesizer. The performances achieved beat note linewidth below 30 Hz.

Numerical modeling of heat and mass transfer in the human eye under millimeter wave exposure.

PubMed

Karampatzakis, Andreas; Samaras, Theodoros

2013-05-01

Human exposure to millimeter wave (MMW) radiation is expected to increase in the next several years. In this work, we present a thermal model of the human eye under MMW illumination. The model takes into account the fluid dynamics of the aqueous humor and predicts a frequency-dependent reversal of its flow that also depends on the incident power density. The calculated maximum fluid velocity in the anterior chamber and the temperature rise at the corneal apex are reported for frequencies from 40 to 100 GHz and different values of incident power density. Copyright © 2013 Wiley Periodicals, Inc.

Millimeter-wave surface resistance of laser-ablated YBa2Cu3O(7-delta) superconducting films

NASA Technical Reports Server (NTRS)

Miranda, F. A.; Gordon, W. L.; Bhasin, K. B.; Warner, J. D.

1990-01-01

The millimeter-wave surface resistance of YBa2Cu3O(7-delta) superconducting films was measured in a gold-plated copper host cavity at 58.6 GHz between 25 and 300 K. High-quality laser-ablated films of 1.2-micron thickness were deposited on SrTiO3 and LaGaO3 substrates. Their transition temperatures were 90.0 and 88.9 K, with a surface resistance at 70 K of 82 and 116 milliohms, respectively. These values are better than the values for the gold-plated cavity at the same temperature and frequency.

Active radiometer for self-calibrated furnace temperature measurements

DOEpatents

Woskov, Paul P.; Cohn, Daniel R.; Titus, Charles H.; Wittle, J. Kenneth; Surma, Jeffrey E.

1996-01-01

Radiometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The radiometer includes a heterodyne millimeter/submillimeter-wave receiver including a millimeter/submillimeter-wave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement.

A novel OCS millimeter-wave generation scheme with data carried only by one sideband and wavelength reuse for uplink connection

NASA Astrophysics Data System (ADS)

Zhu, Zihang; Zhao, Shanghong; Yao, Zhoushi; Tan, Qinggui; Li, Yongjun; Chu, Xingchun; Shi, Lei; Hou, Rui

2012-11-01

We propose a novel optical carrier suppression (OCS) millimeter-wave generation scheme with data carried only by one sideband using a dual-drive Mach-Zehnder modulator (MZM) in radio-over-fiber system, and the transmission performance is also investigated. As the signal is transmitted along the fiber, there is no time shifting of the codes caused by chromatic dispersion. Simulation results show that the eye diagram keeps open and clear even when the optical millimeter-waves are transmitted over 110 km and the power penalty is about 1.9 dB after fiber transmission distance of 60 km. Furthermore, due to the +1 order sideband carrying no data, a full duplex radio-over-fiber link based on wavelength reuse is also built to simplify the base station. The bidirectional 2.5 Gbit/s data is successfully transmitted over a 40 km standard single mode fiber with less than 0.8 dB power penalty in the simulation. Both theoretical analysis and simulation results show that our scheme is feasible and we can obtain a simple cost-efficient configuration and good performance over long-distance transmission.

THE CHROMOSPHERIC SOLAR MILLIMETER-WAVE CAVITY ORIGINATES IN THE TEMPERATURE MINIMUM REGION

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 millimetermore » 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.« less

Computer aided design of monolithic microwave and millimeter wave integrated circuits and subsystems

NASA Astrophysics Data System (ADS)

Ku, Walter H.

1987-08-01

This interim technical report presents results of research on the computer aided design of monolithic microwave and millimeter wave integrated circuits and subsystems. A specific objective is to extend the state-of-the-art of the Computer Aided Design (CAD) of the monolithic microwave and millimeter wave integrated circuits (MIMIC). In this reporting period, we have derived a new model for the high electron mobility transistor (HEMT) based on a nonlinear charge control formulation which takes into consideration the variation of the 2DEG distance offset from the heterointerface as a function of bias. Pseudomorphic InGaAs/GaAs HEMT devices have been successfully fabricated at UCSD. For a 1 micron gate length, a maximum transconductance of 320 mS/mm was obtained. In cooperation with TRW, devices with 0.15 micron and 0.25 micron gate lengths have been successfully fabricated and tested. New results on the design of ultra-wideband distributed amplifiers using 0.15 micron pseudomorphic InGaAs/GaAs HEMT's have also been obtained. In addition, two-dimensional models of the submicron MESFET's, HEMT's and HBT's are currently being developed for the CRAY X-MP/48 supercomputer. Preliminary results obtained are also presented in this report.

Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCloy, J. S.; Sundaram, S. K.; Matyas, J.

Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system,more » describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. Finally, these results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.« less

Study of transmission line attenuation in broad band millimeter wave frequency range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandya, Hitesh Kumar B.; Austin, M. E.; Ellis, R. F.

2013-10-15

Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmosphericmore » water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.« less

Guided waves and ultrasonic characterization of three-dimensional composites

NASA Astrophysics Data System (ADS)

Leymarie, Nicolas; Baste, Stéphane

2000-05-01

Ultrasonic NDE of anisotropic media appears nowadays as one of the best experimental approaches in studying mechanical properties. A complete identification of stiffness tensor can be performed with phase velocity measurements of obliquely incidence ultrasonic bulk waves from water onto a plate. The medium considered, however, has to be homogeneous with respect to wavelength used. In the case of 3D-composites, textures scales may reach one millimeter and their cut-off frequency is less than MHz. The dispersion curves observed in the considered range of frequencies are often very close and sometimes may be overlapped. Experimental studies show complex signals, which are due to a combination of both bulk and guided waves. Wave-speed measurements of the bulk wave and its detection become unreliable with classical techniques of signal processing (simple time or spectral analysis). Moreover, even if the coupled time-frequency analysis with wavelet transforms allows a better interpretation of the signal, the time delay estimation for the bulk wave and so the characterization of the material remains uncertain. To understand blended signals more accurately, different analytical and numerical models are proposed to show the advantages and disadvantages of methods used in NDE.

A Novel Split-Waveguide Mount Design For MM and SubMM wave frequency multipliers and Harmonic Mixers

NASA Technical Reports Server (NTRS)

Raisanen, Anti V.; Choudhury, Debabani; Dengler, Robert J.; Oswald, John E.; Siegel, Peter H.

1993-01-01

A novel split-waveguide mount for millimeter and submillimeter wave frequency multipliers and harmonic mixers is presented. It consists of only two pieces, block halves, which are mirror images of each other.

W-Band On-Wafer Measurement of Uniplanar Slot-Type Antennas

NASA Technical Reports Server (NTRS)

Raman, Sanjay; Gauthier, Gildas P.; Rebeiz, Gabriel M.

1997-01-01

Uniplanar slot-type antennas such as coplanar waveguide fed single- and dual-polarized slot-ring antennas and double folded-slot antennas are characterized using a millimeter-wave network analyzer and on-wafer measurement techniques. The antennas are designed to be mounted on a dielectric lens to minimize power loss into substrate modes and realize high-gain antenna patterns. On-wafer measurements are performed by placing the antenna wafer on a thick dielectric spacer of similar e(sub t) and eliminating the reflection from the probe station chuck with time-domain gating. The measured results agree well with method-of-moments simulations.

CCAM: A novel millimeter-wave instrument using a close-packed TES bolometer array

NASA Astrophysics Data System (ADS)

Lau, Judy M.

This thesis describes CCAM, an instrument designed to map the Cosmic Microwave Background (CMB), and also presents some of the initial measurements made with CCAM on the Atacama Cosmology Telescope (ACT). CCAM uses a CCD-like camera of millimeter-wave TES bolometers. It employs new detector technology, read-out electronics, cold re-imaging optics, and cryogenics to obtain high sensitivity CMB anisotropy measurements. The free-standing 8×32 close-packed array of pop- up TES detectors is the first of its kind to observe the sky at 145 GHz. We present the design of the receiver including the antireflection coated silicon lens re-imaging system, construction and optimization of the pulse tube/ sorption refrigerator cryogenic system, as well as the technology developed to integrate eight 1×32 TES columns and accompanying read-out electronics in to an array of 256 millimeter-wave detectors into a focal plane area of 3.5 cm 2. The performance of the detectors and optics prior to deployment at the ACT site in Chile are reported as well as preliminary performance results of the instrument when optically paired with the ACT telescope in the summer of 2007. Here, we also report on the feasibility of the TES detector array to measure polarization when coupled to a rotating birefringent sapphire half wave plate and wire-grid polarizer.

TEMPEST-D MM-Wave Radiometer

NASA Astrophysics Data System (ADS)

Padmanabhan, S.; Gaier, T.; Reising, S. C.; Lim, B.; Stachnik, R. A.; Jarnot, R.; Berg, W. K.; Kummerow, C. D.; Chandrasekar, V.

2016-12-01

The TEMPEST-D radiometer is a five-frequency millimeter-wave radiometer at 89, 165, 176, 180, and 182 GHz. The direct-detection architecture of the radiometer reduces its power consumption and eliminates the need for a local oscillator, reducing complexity. The Instrument includes a blackbody calibrator and a scanning reflector, which enable precision calibration and cross-track scanning. The MMIC-based millimeter-wave radiometers take advantage of the technology developed under extensive investment by the NASA Earth Science Technology Office (ESTO). The five-frequency millimeter-wave radiometer is built by Jet Propulsion Laboratory (JPL), which has produced a number of state-of-the-art spaceborne microwave radiometers, such as the Microwave Limb Sounder (MLS), Advanced Microwave Radiometer (AMR) for Jason-2/OSTM, Jason-3, and the Juno Microwave Radiometer (MWR). The TEMPEST-D Instrument design is based on a 165 to 182 GHz radiometer design inherited from RACE and an 89 GHz receiver developed under the ESTO ACT-08 and IIP-10 programs at Colorado State University (CSU) and JPL. The TEMPEST reflector scan and calibration methodology is adapted from the Advanced Technology Microwave Sounder (ATMS) and has been validated on the Global Hawk unmanned aerial vehicle (UAV) using the High Altitude MMIC Sounding radiometer (HAMSR) instrument. This presentation will focus on the design, development and performance of the TEMPEST-D radiometer instrument. The flow-down of the TEMPEST-D mission objectives to instrument level requirements will also be discussed.

Millimeter Wave Generation by Relativistic Electron Beams.

DTIC Science & Technology

1984-12-01

frequency and wave vector matching relations for influence of various nonlinear effects on this instability is this four-wave interaction require...following coupled mode equations _ 6 = 6 _ (14)-- v vx (14) ." .’ for the lower hybrid sidebands: v - V 2 - The x component of the resultant vector equation...involves a purely growing modte, a four-wave interaction plitoces is analysed, including a u ap ti wave- vector up-shifted and ilown-shiftes upper

A Study of the Interaction of Millimeter Wave Fields with Biological Systems.

DTIC Science & Technology

1984-07-01

structurally complex proteins . The third issue is the relevance of the parameters used in previous modeling efforts. The strength of the exciton-phonon...modes of proteins in the millimeter and submillimeter regions of the electromagnetic spectrum. Specifically: o " Four separate groups of frequencies...Rhodopseudomonas Sphaeroides (4). In industrial or military environments a significant number of personnel are exposed to electromagnetic fields

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.

Millimeter and Submillimeter Wave Spectroscopy of Higher Energy Conformers of 1,2-PROPANEDIOL

NASA Astrophysics Data System (ADS)

Zakharenko, Olena; Bossa, Jean-Baptiste; Lewen, Frank; Schlemmer, Stephan; Müller, Holger S. P.

2017-06-01

We have performed a study of the millimeter/submillimeter wave spectrum of four higher energy conformers of 1,2-propanediol (continuation of the previous study on the three lowest energy conformers. 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. J.-B. Bossa, M.H. Ordu, H.S.P. Müller, F. Lewen, S. Schlemmer, A&A 570 (2014) A12)

VizieR Online Data Catalog: Iso-propyl cyanide rotational study (Kolesnikova+, 2017)

NASA Astrophysics Data System (ADS)

Kolesnikova, L.; Alonso, E. R.; Mata, S.; Cernicharo, J.; Alonso, J. L.

2018-02-01

A detailed analysis of the rotational spectra of the interstellar iso-propyl cyanide has been carried out up to 480GHz using three different high-resolution spectroscopic techniques. Jet-cooled broadband chirped pulse Fourier transform microwave spectroscopy from 6 to 18GHz allowed us to measure and analyze the ground-state rotational transitions of all singly substituted 13C and 15N isotopic species in their natural abundances. The monohydrate of iso-propyl cyanide, in which the water molecule bounds through a stronger O-H...N and weaker bifurcated (C-H)2...O hydrogen bonds in a Cs configuration, has also been detected in the supersonic expansion. Stark-modulation spectroscopy in the microwave and millimeter wave range from 18 to 75GHz allowed us to analyze the vibrational satellite pattern arising from pure rotational transitions in the low-lying vibrational excited states. Finally, assignments and measurements were extended through the millimeter and submillimeter wave region. The room temperature rotational spectra made possible the assignment and analysis of pure rotational transitions in 19 vibrationally excited states. Significant perturbations were found above 100GHz in most of the observed excited states. Due to the complexity of the interactions and importance of this astrophysical region for future radioastronomical detection, both a graphical plot approach and a coupled fit have been used to assign and measure almost 10000 new lines. (1 data file).

A Comprehensive Rotational Study of Interstellar Iso-propyl Cyanide up to 480 GHz

NASA Astrophysics Data System (ADS)

Kolesniková, L.; Alonso, E. R.; Mata, S.; Cernicharo, J.; Alonso, J. L.

2017-12-01

A detailed analysis of the rotational spectra of the interstellar iso-propyl cyanide has been carried out up to 480 GHz using three different high-resolution spectroscopic techniques. Jet-cooled broadband chirped pulse Fourier transform microwave spectroscopy from 6 to 18 GHz allowed us to measure and analyze the ground-state rotational transitions of all singly substituted 13C and 15N isotopic species in their natural abundances. The monohydrate of iso-propyl cyanide, in which the water molecule bounds through a stronger O-H⋯N and weaker bifurcated (C-H)2⋯O hydrogen bonds in a C s configuration, has also been detected in the supersonic expansion. Stark-modulation spectroscopy in the microwave and millimeter wave range from 18 to 75 GHz allowed us to analyze the vibrational satellite pattern arising from pure rotational transitions in the low-lying vibrational excited states. Finally, assignments and measurements were extended through the millimeter and submillimeter wave region. The room temperature rotational spectra made possible the assignment and analysis of pure rotational transitions in 19 vibrationally excited states. Significant perturbations were found above 100 GHz in most of the observed excited states. Due to the complexity of the interactions and importance of this astrophysical region for future radioastronomical detection, both a graphical plot approach and a coupled fit have been used to assign and measure almost 10,000 new lines.

Experimental Verification of Guided-Wave Lumped Circuits Using Waveguide Metamaterials

NASA Astrophysics Data System (ADS)

Li, Yue; Zhang, Zhijun

2018-04-01

Through the construction and characterization in microwave frequencies, we experimentally demonstrate our recently developed theory of waveguide lumped circuits, i.e., waveguide metatronics [Sci. Adv. 2, e1501790 (2016), 10.1126/sciadv.1501790], as a method to design subwavelength-scaled analog circuits. In the paradigm of waveguide metatronics, numbers of lumped inductors and capacitors are easily integrated functionally inside the waveguide, which is an irreplaceable transmission line in millimeter-wave and terahertz systems with the advantages of low radiation loss and low crosstalk. An example of multiple-ordered metatronic filters with layered structures is fabricated utilizing the technique of substrate integrated waveguides, which can be easily constructed by the printed-circuit-board process. The materials used in the construction are also typical microwave materials with positive permittivity, low loss, and negligible dispersion, imitating the plasmonic materials with negative permittivity in the optical domain. The results verify the theory of waveguide metatronics, which provides an efficient platform of functional lumped circuit design for guided-wave processing.

Electromagnetic wave propagation in rain and polarization effects

PubMed Central

OKAMURA, Sogo; OGUCHI, Tomohiro

2010-01-01

This paper summarizes our study on microwave and millimeter-wave propagation in rain with special emphasis on the effects of polarization. Starting from a recount of our past findings, we will discuss developments with these and how they are connected with subsequent research. PMID:20551593

Four-amplitude shift keying-single sideband millimeter-wave signal generation with frequency sextupling based on optical phase modulation

NASA Astrophysics Data System (ADS)

Wu, Peng; Ma, Jianxin

2017-03-01

We have proposed and demonstrated a scheme to generate a frequency-sextupling amplitude shift keying (ASK)-single sideband optical millimeter (mm)-wave signal with high dispersion tolerance based on an optical phase modulator (PM) by ably using the-4th-order and +2nd-order sidebands of the optical modulation. The ASK radio frequency signal, superposed by a local oscillator with the same frequency, modulates the lightwave via an optical PM with proper voltage amplitudes, the +2nd-order sideband carries the ASK signal with a constant slope while the -4th-order sideband maintains constant amplitude. These two sidebands can be abstracted by a wavelength selective switch to form a dual-tone optical mm-wave with only one tone carrying the ASK signal. As only one tone bears the ASK signal while the other tone is unmodulated, the generated dual-tone optical mm-wave signal has high dispersion tolerance.

Free-space microwave-to-optical conversion via six-wave mixing in Rydberg atoms

NASA Astrophysics Data System (ADS)

Han, Jingshan; Vogt, Thibault; Gross, Christian; Jaksch, Dieter; Kiffner, Martin; Li, Wenhui

2017-04-01

The interconversion of millimeter waves and optical fields is an important and highly topical subject for classical and quantum technologies. In this talk, we report an experimental demonstration of coherent and efficient microwave-to-optical conversion in free space via six-wave mixing in Rydberg atoms. Our scheme utilizes the strong coupling of millimeter waves to Rydberg atoms as well as the frequency mixing based on electromagnetically induced transparency (EIT) that greatly enhances the nonlinearity for the conversion process. We achieve a free-space conversion efficiency of 0.25% with a bandwidth of about 4 MHz in our experiment. Optimized geometry and energy level configurations should enable the broadband interconversion of microwave and optical fields with near-unity efficiency. These results indicate the tremendous potential of Rydberg atoms for the efficient conversion between microwave and optical fields, and thus paves the way to many applications. This work is supported by Singapore Ministry of Education Academic Research Fund Tier 2 (Grant No. MOE2015-T2-1-085).

Application of fluorescent dyes for some problems of bioelectromagnetics

NASA Astrophysics Data System (ADS)

Babich, Danylo; Kylsky, Alexandr; Pobiedina, Valentina; Yakunov, Andrey

2016-04-01

Fluorescent organic dyes solutions are used for non-contact measurement of the millimeter wave absorption in liquids simulating biological tissue. There is still not any certain idea of the physical mechanism describing this process despite the widespread technology of microwave radiation in the food industry, biotechnology and medicine. For creating adequate physical model one requires an accurate command of knowledge concerning to the relation between millimeter waves and irradiated object. There were three H-bonded liquids selected as the samples with different coefficients of absorption in the millimeter range like water (strong absorption), glycerol (medium absorption) and ethylene glycol (light absorption). The measurements showed that the greatest response to the action of microwaves occurs for glycerol solutions: R6G (building-up luminescence) and RC (fading luminescence). For aqueous solutions the signal is lower due to lower quantum efficiency of luminescence, and for ethylene glycol — due to the low absorption of microwaves. In the area of exposure a local increase of temperature was estimated. For aqueous solutions of both dyes the maximum temperature increase is about 7° C caused with millimeter waves absorption, which coincides with the direct radio physical measurements and confirmed by theoretical calculations. However, for glycerol solution R6G temperature equivalent for building-up luminescence is around 9° C, and for the solution of ethylene glycol it's about 15°. It is assumed the possibility of non-thermal effect of microwaves on the different processes and substances. The application of this non-contact temperature sensing is a simple and novel method to detect temperature change in small biological objects.

Backscattering enhancement with a finite beam width for millimeter-wavelength weather radars

NASA Astrophysics Data System (ADS)

Kobayashi, Satoru; Tanelli, Simone; Iguchi, Toshio; Im, Eastwood

2004-12-01

Backscattering enhancement from random hydrometeors should increase as wavelengths of radars reach millimeter regions. For 95 GHz radars, the reflectivity of backscattering is expected to increase by 2 dB, due to multiple scattering including backscattering enhancement, for water droplets of diameter of 1 mm with a density of 5 x 103 m-3. Previous theoretical studies of backscattering enhancement considered infinitely extending plane waves. In this paper, we expand the theory to spherical waves with a Gaussian antenna pattern, including depolarizing effects. While the differences from the plane wave results are not great when the optical thickness is small, as the latter increases the differences become significant, and essentially depend on the ratio of radar footprint radius to the mean free path of hydrometeors. In this regime, for a radar footprint that is smaller than the mean free path, the backscattering-enhancement reflectivity corresponding to spherical waves is significantly less pronounced than in the case of the plane wave theory. Hence this reduction factor must be taken into account when analyzing radar reflectivity factors for use in remote sensing applications.

A millimeter wave Josephson mixer employing a high-T(c) GdBaCuO point contact

NASA Technical Reports Server (NTRS)

Olsson, H. K.; Claeson, T.; Eriksson, S.; Johansson, L.-G.; Mcgrath, W. R.

1987-01-01

A Josephson effect heterodyne mixer for the millimeter wave band was investigated employing high-T(c) GdBaCuO point contacts. Mixer performance was in qualitative agreement with theory. A mixing response was observed up to 55 K, the highest operating temperature achieved for such a device to date. The voltage separation of RF-induced steps gave a value of h/2e = 2.08 x 10 to the -15th V s, which is in excellent agreement with the value expected for Cooper pairs. In addition, the temperature dependence of the I(0)R product was found to agree with Bardeen-Cooper-Schrieffer theory in the weak coupling limit.

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.

Analysis of Pheochromocytoma (PC12) Membrane Potential under the Exposure to Millimeter-wave Radiation

NASA Astrophysics Data System (ADS)

Mizuno, M.; Hirata, A.; Kawase, K.; Otani, C.; Nagatsuma, T.

2004-08-01

Non-thermal effects of millimeter wave (MMW) on Pheochromocytoma (PC12) were studied by potential measurement with a voltage sensitive dye (DiBAC4(3)). Cells were irradiated at fixed frequencies of 30, 40, 60, 76GHz as well as sweeping frequency between 10 and 100 GHz by an MMW generator based on a uni-traveling-carrier photodiode (UTC-PD), the most widely tunable MMW source. However there were no significant changes in membrane potential between MMW-irradiated and control cells. The results suggest that MMW irradiation in the range from 10 to 100GHz appears to be safe for ordinary PC12 cells under non-thermal conditions.

Design and construction of high-sensitivity, infrared bolometers for operation at 300 mK

NASA Technical Reports Server (NTRS)

Alsop, D. C.; Inman, C.; Lange, A. E.; Wibanks, T.

1992-01-01

The design and construction of 300-mK composite bolometers developed for millimeter-wave astronomical observations are described. Graphite fibers are used as the electrical leads for the thermistor to reduce the thermal conductance and heat capacity associated with the leads. A mechanical suspension made of Nylon fibers provides the required thermal conductance. Electrical noise equivalent powers below 1 x 10 exp -16 W/sq rt Hz have been achieved for detectors with thermal time constants of 11 ms. The detectors were installed in a millimeter-wave photometer and used to perform observations of the cosmic microwave background from a balloonborne platform. The flight performance was consistent with the measured laboratory properties.

Active radiometer for self-calibrated furnace temperature measurements

DOEpatents

Woskov, P.P.; Cohn, D.R.; Titus, C.H.; Wittle, J.K.; Surma, J.E.

1996-11-12

A radiometer is described with a probe beam superimposed on its field-of-view for furnace temperature measurements. The radiometer includes a heterodyne millimeter/submillimeter-wave receiver including a millimeter/submillimeter-wave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement. 5 figs.

Millimeter and X-Ray Emission from the 5 July 2012 Solar Flare

NASA Astrophysics Data System (ADS)

Tsap, Y. T.; Smirnova, V. V.; Motorina, G. G.; Morgachev, A. S.; Kuznetsov, S. A.; Nagnibeda, V. G.; Ryzhov, V. S.

2018-03-01

The 5 July 2012 solar flare SOL2012-07-05T11:44 (11:39 - 11:49 UT) with an increasing millimeter spectrum between 93 and 140 GHz is considered. We use space and ground-based observations in X-ray, extreme ultraviolet, microwave, and millimeter wave ranges obtained with the Reuven Ramaty High-Energy Solar Spectroscopic Imager, Solar Dynamics Observatory (SDO), Geostationary Operational Environmental Satellite, Radio Solar Telescope Network, and Bauman Moscow State Technical University millimeter radio telescope RT-7.5. The main parameters of thermal and accelerated electrons were determined through X-ray spectral fitting assuming the homogeneous thermal source and thick-target model. From the data of the Atmospheric Imaging Assembly/SDO and differential-emission-measure calculations it is shown that the thermal coronal plasma gives a negligible contribution to the millimeter flare emission. Model calculations suggest that the observed increase of millimeter spectral flux with frequency is determined by gyrosynchrotron emission of high-energy (≳ 300 keV) electrons in the chromosphere. The consequences of the results are discussed in the light of the flare-energy-release mechanisms.

Self-calibrated active pyrometer for furnace temperature measurements

DOEpatents

Woskov, Paul P.; Cohn, Daniel R.; Titus, Charles H.; Surma, Jeffrey E.

1998-01-01

Pyrometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The pyrometer includes a heterodyne millimeter/sub-millimeter-wave or microwave receiver including a millimeter/sub-millimeter-wave or microwave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement. In an alternative embodiment, a translatable base plate and a visible laser beam allow slow mapping out of interference patterns and obtaining peak values therefor. The invention also includes a waveguide having a replaceable end portion, an insulating refractory sleeve and/or a source of inert gas flow. The pyrometer may be used in conjunction with a waveguide to form a system for temperature measurements in a furnace. The system may employ a chopper or alternatively, be constructed without a chopper. The system may also include an auxiliary reflector for surface emissivity measurements.

Lesion contrast and detection using sonoelastographic shear velocity imaging: preliminary results

NASA Astrophysics Data System (ADS)

Hoyt, Kenneth; Parker, Kevin J.

2007-03-01

This paper assesses lesion contrast and detection using sonoelastographic shear velocity imaging. Shear wave interference patterns, termed crawling waves, for a two phase medium were simulated assuming plane wave conditions. Shear velocity estimates were computed using a spatial autocorrelation algorithm that operates in the direction of shear wave propagation for a given kernel size. Contrast was determined by analyzing shear velocity estimate transition between mediums. Experimental results were obtained using heterogeneous phantoms with spherical inclusions (5 or 10 mm in diameter) characterized by elevated shear velocities. Two vibration sources were applied to opposing phantom edges and scanned (orthogonal to shear wave propagation) with an ultrasound scanner equipped for sonoelastography. Demodulated data was saved and transferred to an external computer for processing shear velocity images. Simulation results demonstrate shear velocity transition between contrasting mediums is governed by both estimator kernel size and source vibration frequency. Experimental results from phantoms further indicates that decreasing estimator kernel size produces corresponding decrease in shear velocity estimate transition between background and inclusion material albeit with an increase in estimator noise. Overall, results demonstrate the ability to generate high contrast shear velocity images using sonoelastographic techniques and detect millimeter-sized lesions.

77 FR 65596 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-29

... to offer remote multi-cast ITCH Wave Ports for clients co-located at other third party data centers... delivery of third party market data to market center clients via a wireless network using millimeter wave... Multi- cast ITCH Wave Ports for clients co-located at other third-party data centers, through which...

Full-duplex radio-over-fiber system with tunable millimeter-wave signal generation and wavelength reuse for upstream signal.

PubMed

Wang, Yiqun; Pei, Li; Li, Jing; Li, Yueqin

2017-06-10

A full-duplex radio-over-fiber system is proposed, which provides both the generation of a millimeter-wave (mm-wave) signal with tunable frequency multiplication factors (FMFs) and wavelength reuse for uplink data. A dual-driving Mach-Zehnder modulator and a phase modulator are cascaded to form an optical frequency comb. An acousto-optic tunable filter based on a uniform fiber Bragg grating (FBG-AOTF) is employed to select three target optical sidebands. Two symmetrical sidebands are chosen to generate mm waves with tunable FMFs up to 16, which can be adjusted by changing the frequency of the applied acoustic wave. The optical carrier is reused at the base station for uplink connection. FBG-AOTFs driven by two acoustic wave signals are experimentally fabricated and further applied in the proposed scheme. Results of the research indicate that the 2-Gbit/s data can be successfully transmitted over a 25-km single-mode fiber for bidirectional full-duplex channels with power penalty of less than 2.6 dB. The feasibility of the proposed scheme is verified by detailed simulations and partial experiments.

An Open Rectangular Waveguide Grating for Millimeter-Wave Traveling-Wave Tubes

NASA Astrophysics Data System (ADS)

Liao, Ming-Liang; Wei, Yan-Yu; Wang, Hai-Long; Huang, Yu; Xu, Jin; Liu, Yang; Guo, Guo; Niu, Xin-Jian; Gong, Yu-Bin; Park, Gun-Sik

2016-09-01

Not Available Supported by the National Natural Science Foundation of China under Grant No 61271029, the National Science Fund for Distinguished Young Scholars of China under Grant No 61125103, and the National Research Foundation of Korea under Grant No MSIP: NRF-2009-0083512.

Millimeter-Wave Generation Via Plasma Three-Wave Mixing

DTIC Science & Technology

1988-06-01

are coupled to a third space -charge wave with dispersion 2w W k -k k . (16) A plasma-loaded-waveguide mode is excited at the intersection of this...DISPERSION "FAST" W PLASMA WAVE Wc PLASMA WAVE A-lA oppositely directed EPWs with different phase velocities (wp/k., and wO/k. 2) are coupled to a third ... space -charge wave with dispersion 2w I- k k .(16) e 2 A plaama-loaded-waveguide mode is excited at the intersection of this coupled space-charge wave

Expanding the spectrum: 20 years of advances in MMW imagery

NASA Astrophysics Data System (ADS)

Martin, Christopher A.; Lovberg, John A.; Kolinko, Valdimir G.

2017-05-01

Millimeter-wave imaging has expanded from the single-pixel swept imagers developed in the 1960s to large field-ofview real-time systems in use today. Trex Enterprises has been developing millimeter-wave imagers since 1991 for aviation and security applications, as well as millimeter-wave communications devices. As MMIC device development was stretching into the MMW band in the 1990s, Trex developed novel imaging architectures to create 2-D staring systems with large pixel counts and no moving parts while using a minimal number of devices. Trex also contributed to the device development in amplifiers, switches, and detectors to enable the next generation of passive MMW imaging systems. The architectures and devices developed continue to be employed in security imagers, radar, and radios produced by Trex. This paper reviews the development of the initial real-time MMW imagers and associated devices by Trex Enterprises from the 1990s through the 2000s. The devices include W-band MMIC amplifiers, switches, and detector didoes, and MMW circuit boards and optical processors. The imaging systems discussed include two different real-time passive MMW imagers flown on helicopters and a MMW radar system, as well as implementation of the devices and architectures in simpler stand-off and gateway security imagers.

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.

Millimeter wave scattering characteristics and radar cross section measurements of common roadway objects

NASA Astrophysics Data System (ADS)

Zoratti, Paul K.; Gilbert, R. Kent; Majewski, Ronald; Ference, Jack

1995-12-01

Development of automotive collision warning systems has progressed rapidly over the past several years. A key enabling technology for these systems is millimeter-wave radar. This paper addresses a very critical millimeter-wave radar sensing issue for automotive radar, namely the scattering characteristics of common roadway objects such as vehicles, roadsigns, and bridge overpass structures. The data presented in this paper were collected on ERIM's Fine Resolution Radar Imaging Rotary Platform Facility and processed with ERIM's image processing tools. The value of this approach is that it provides system developers with a 2D radar image from which information about individual point scatterers `within a single target' can be extracted. This information on scattering characteristics will be utilized to refine threat assessment processing algorithms and automotive radar hardware configurations. (1) By evaluating the scattering characteristics identified in the radar image, radar signatures as a function of aspect angle for common roadway objects can be established. These signatures will aid in the refinement of threat assessment processing algorithms. (2) Utilizing ERIM's image manipulation tools, total RCS and RCS as a function of range and azimuth can be extracted from the radar image data. This RCS information will be essential in defining the operational envelope (e.g. dynamic range) within which any radar sensor hardware must be designed.

The effects of scattering on the relative LPI performance of optical and mm-wave systems

NASA Astrophysics Data System (ADS)

Oetting, John; Hampton, Jerry

1988-01-01

Previous results comparing the LPI performance of optical and millimeter-wave satellite systems is extended to include the effects of scattering on optical LPI performance. The LPI figure of merit used to compare the two media is the circular equivalent vulnerability radius (CEVR). The CEVR is calculated for typical optical and spread spectrum millimeter-wave systems, and the LPI performance tradeoffs available with each medium are compared. Attention is given to the possibility that light will be scattered into the interceptor's FOV and thereby enable detection in geometries in which interception of the main beam is impossible. The effects of daytime vs. nighttime operation of the optical LPI system are also considered. Some illustrative results for the case of a ground-to-space uplink to a low earth orbit satellite are presented, along with some conclusions and unresolved issues for further study.

Photonic generation of background-free millimeter-wave ultra-wideband pulses based on a single dual-drive Mach-Zehnder modulator.

PubMed

Li, Wei; Wang, Wen Ting; Sun, Wen Hui; Wang, Li Xian; Zhu, Ning Hua

2014-03-01

We propose a novel photonic approach for generating a background-free millimeter-wave (MMW) ultra-wideband (UWB) signal based on a conventional dual-drive Mach-Zehnder modulator (DMZM). One arm of the DMZM is driven by a local oscillator (LO) signal. The LO power is optimized to realize optical carrier suppressed modulation. The other arm is fed by a rectangular signal. The MMW UWB pulses are generated by truncating the continuous wave LO signal into a pulsed one in a photodetector (PD). The generated MMW UWB signal is background-free by eliminating the baseband frequency components because the optical power launched to the PD keeps constant all the time. The proposed method is theoretically analyzed and experimentally verified. The generated MMW UWB signal centered at a frequency of 26 GHz meets the Federal Communications Commission spectral mask very well.

Printed circuit board impedance matching step for microwave (millimeter wave) devices

DOEpatents

Pao, Hsueh-Yuan; Aguirre, Jerardo; Sargis, Paul

2013-10-01

An impedance matching ground plane step, in conjunction with a quarter wave transformer section, in a printed circuit board provides a broadband microwave matching transition from board connectors or other elements that require thin substrates to thick substrate (>quarter wavelength) broadband microwave (millimeter wave) devices. A method of constructing microwave and other high frequency electrical circuits on a substrate of uniform thickness, where the circuit is formed of a plurality of interconnected elements of different impedances that individually require substrates of different thicknesses, by providing a substrate of uniform thickness that is a composite or multilayered substrate; and forming a pattern of intermediate ground planes or impedance matching steps interconnected by vias located under various parts of the circuit where components of different impedances are located so that each part of the circuit has a ground plane substrate thickness that is optimum while the entire circuit is formed on a substrate of uniform thickness.

Optical single sideband millimeter-wave signal generation and transmission using 120° hybrid coupler

NASA Astrophysics Data System (ADS)

Zheng, Zhiwei; Peng, Miao; Zhou, Hui; Chen, Ming; Jiang, Leyong; Tan, Li; Dai, Xiaoyu; Xiang, Yuanjiang

2018-03-01

We propose a novel 60 GHz optical single sideband (OSSB) millimeter-wave (mm-wave) signal generation scheme using 120° hybrid coupler based on external integrated Mach-Zehnder modulator (MZM). The proposed scheme shows that the bit error ratio (BER) performance is improved by suppressing the +2nd-order sideband. Meanwhile, the transmission distance is extended as only the optical +1st-order sideband is modulated by using 5 Gbit/s baseband signal while the carrier is blank, owing to the elimination of walk-off effect suffered from fiber dispersion. The simulation results demonstrated that the eye diagrams of the generated 60 GHz OSSB signal keep open and clear after 100 km standard single-mode fiber (SSMF). In addition, the proposed scheme can achieve 2 dB receiver sensitivity improvements than the conventional 90° hybrid coupler when transmitted over 100 km SSMF at a BER of 10-9.

Electromagnetic properties of polycrystalline diamond from 35 K to room temperature and microwave to terahertz frequencies

NASA Astrophysics Data System (ADS)

Floch, Jean-Michel Le; Bara, Romain; Hartnett, John G.; Tobar, Michael E.; Mouneyrac, David; Passerieux, Damien; Cros, Dominique; Krupka, Jerzy; Goy, Philippe; Caroopen, Sylvain

2011-05-01

Dielectric resonators are key components for many microwave and millimeter wave applications, including high-Q filters and frequency-determining elements for precision frequency synthesis. These often depend on the quality of the dielectric material. The commonly used material for building the best cryogenic microwave oscillators is sapphire. However, sapphire is becoming a limiting factor for higher frequency designs. It is, then, important to find new candidates that can fulfill the requirements for millimeter wave low noise oscillators at room and cryogenic temperatures. These clocks are used as a reference in many fields, such as modern telecommunication systems, radio astronomy (very-long-baseline interferometry), and precision measurements at the quantum limit. High resolution measurements were taken of the temperature-dependence of the electromagnetic properties of a polycrystalline diamond disk at temperatures between 35 and 330 K at microwave to submillimeter wave frequencies. The cryogenic measurements were made using a TE01δ dielectric mode resonator placed inside a vacuum chamber connected to a single-stage pulse-tube cryocooler. The high frequency characterization was performed at room temperature using a combination of a quasi-optical two-lens transmission setup, a Fabry-Perot cavity, and a whispering gallery mode resonator excited with waveguides. Our CVD diamond sample exhibits a decreasing loss tangent with increasing frequencies. We compare the results with well known crystals. This comparison makes it clear that polycrystalline diamond could be an important material for generating stable frequencies at millimeter waves.

Effect of 99 GHz continuous millimeter wave electro-magnetic radiation on E. coli viability and metabolic activity.

PubMed

Cohen, Irena; Cahan, Rivka; Shani, Gad; Cohen, Eyal; Abramovich, Amir

2010-05-01

To investigate time exposure dependence of continuous millimeter wave (CW) 99 GHz radiation on Escherichia coli bacterial cell viability and metabolic activity. Suspensions of E. coli bacterial cells with an optical density of OD(660 nm) = 0.1 were used for viability tests and OD(660 nm) = 1.0 for metabolic activity tests. These suspensions were exposed to 99 GHz CW electromagnetic radiation, generated by a Backward Wave Oscillator (BWO) tube base instrument with a horn antenna at the BWO exit, to obtain an almost ideal Gaussian beam. Calculations of the Gaussian beam show that a power of 0.2 mW/cm(2) was obtained at the bacterial plane. The experimental results show that 1 hour of exposure to 99 GHz CW electromagnetic radiation had no effect on E. coli viability and colony characterisation. In 19 h of radiation, the number of colonies forming units was half order of magnitude higher than the sham-exposed and the control. However, 19 h of exposure did not affect the E. coli metabolic activity. Exposure of E. coli to millimeter wave (MW) CW 99 GHz radiation for a short period did not affect the viability of E. coli bacterial cells. However, exposure for 19 h caused a slight proliferation but did not influence the metabolic activities of about 90 biochemical reactions that were examined. Hence, we assume that the slight proliferation (half order of magnitude) after 19 h of exposure dose not have a biological meaning.

Remote sensing science for the Nineties; Proceedings of IGARSS '90 - 10th Annual International Geoscience and Remote Sensing Symposium, University of Maryland, College Park, May 20-24, 1990. Vols. 1, 2, & 3

NASA Technical Reports Server (NTRS)

1990-01-01

Various papers on remote sensing (RS) for the nineties are presented. The general topics addressed include: subsurface methods, radar scattering, oceanography, microwave models, atmospheric correction, passive microwave systems, RS in tropical forests, moderate resolution land analysis, SAR geometry and SNR improvement, image analysis, inversion and signal processing for geoscience, surface scattering, rain measurements, sensor calibration, wind measurements, terrestrial ecology, agriculture, geometric registration, subsurface sediment geology, radar modulation mechanisms, radar ocean scattering, SAR calibration, airborne radar systems, water vapor retrieval, forest ecosystem dynamics, land analysis, multisensor data fusion. Also considered are: geologic RS, RS sensor optical measurements, RS of snow, temperature retrieval, vegetation structure, global change, artificial intelligence, SAR processing techniques, geologic RS field experiment, stochastic modeling, topography and Digital Elevation model, SAR ocean waves, spaceborne lidar and optical, sea ice field measurements, millimeter waves, advanced spectroscopy, spatial analysis and data compression, SAR polarimetry techniques. Also discussed are: plant canopy modeling, optical RS techniques, optical and IR oceanography, soil moisture, sea ice back scattering, lightning cloud measurements, spatial textural analysis, SAR systems and techniques, active microwave sensing, lidar and optical, radar scatterometry, RS of estuaries, vegetation modeling, RS systems, EOS/SAR Alaska, applications for developing countries, SAR speckle and texture.

Adaptive data rate control TDMA systems as a rain attenuation compensation technique

NASA Technical Reports Server (NTRS)

Sato, Masaki; Wakana, Hiromitsu; Takahashi, Takashi; Takeuchi, Makoto; Yamamoto, Minoru

1993-01-01

Rainfall attenuation has a severe effect on signal strength and impairs communication links for future mobile and personal satellite communications using Ka-band and millimeter wave frequencies. As rain attenuation compensation techniques, several methods such as uplink power control, site diversity, and adaptive control of data rate or forward error correction have been proposed. In this paper, we propose a TDMA system that can compensate rain attenuation by adaptive control of transmission rates. To evaluate the performance of this TDMA terminal, we carried out three types of experiments: experiments using a Japanese CS-3 satellite with Ka-band transponders, in house IF loop-back experiments, and computer simulations. Experimental results show that this TDMA system has advantages over the conventional constant-rate TDMA systems, as resource sharing technique, in both bit error rate and total TDMA burst lengths required for transmitting given information.

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 was created for the ground state and for the two low-lying excited states, and are ideal for a future astronomical research. The 1σ frequency accuracy is lower than 100 kHz for the lines with upper-state energy below 200 cm-1, corresponding to a velocity resolution of 0.1 km s-1 at 300 GHz The spectral line list of hydantoin is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A44

Highly Efficient Broadband Multiplexed Millimeter-Wave Vortices from Metasurface-Enabled Transmit-Arrays of Subwavelength Thickness

NASA Astrophysics Data System (ADS)

Jiang, Zhi Hao; Kang, Lei; Hong, Wei; Werner, Douglas H.

2018-06-01

Structured electromagnetic waves carrying nonvanishing orbital angular momentum (OAM) have recently opened up alternative frontiers in the field of wave physics, holding great promise for a wide range of potential applications. By leveraging geometric phases originating from spin-to-orbital interactions, spin-dependent wave phenomena can be created, leading to a more versatile realm of dispersionless wave-front manipulation. However, the currently available transmissive vortex-beam generators suffer from a narrow bandwidth, require an optically thick device profile, or are limited by a low efficiency, severely restricting their integration into systems and/or widespread usage for practical applications. We present the design methodology and a physical analysis and complete experimental characterization of a class of millimeter-wave Pancharatnam-Berry transmit-arrays with a thickness of about λ0/3 , which enables highly efficient generation and separation of spin-controlled vortex beams over a broad bandwidth, achieving an unprecedented peak efficiency of 88% for a single vortex beam and 71% for dual vortex beams. The proposed transmit-array, which is capable of providing two-dimensional OAM multiplexing and demultiplexing without normal-mode background interference, overcomes all previous roadblocks and paves the way for high-efficiency electromagnetic vortex-beam generation as well as other wave-front-shaping devices from microwave frequencies to optical wavelengths.

Biological Effects of Millimeter-Wave Irradiation.

DTIC Science & Technology

1987-04-01

presence of lines in Raman spectra of baterial cells cm- 1) of the computer driven spectrometer. This is can be claimed to be "...non questionable...the boundary between the in- yeast" ’ was not altered by exposure to mm waves. In 1968. ternal and the external cell environment , membranes also with

Analytical and experimental procedures for determining propagation characteristics of millimeter-wave gallium arsenide microstrip lines

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.

1989-01-01

In this report, a thorough analytical procedure is developed for evaluating the frequency-dependent loss characteristics and effective permittivity of microstrip lines. The technique is based on the measured reflection coefficient of microstrip resonator pairs. Experimental data, including quality factor Q, effective relative permittivity, and fringing for 50-omega lines on gallium arsenide (GaAs) from 26.5 to 40.0 GHz are presented. The effects of an imperfect open circuit, coupling losses, and loading of the resonant frequency are considered. A cosine-tapered ridge-guide text fixture is described. It was found to be well suited to the device characterization.

Millimeter Wave Systems for Airports and Short-Range Aviation Communications: A Survey of the Current Channel Models at mmWave Frequencies

NASA Technical Reports Server (NTRS)

Khatun, Mahfuza; Mehrpouyan, Hani; Matolak, David; Guvenc, Ismail

2017-01-01

Millimeter-wave (mmWave) communications will play a key role in enhancing the throughput, reliability, and security of next generation wireless networks. These advancements are achieved through the large bandwidth available in this band and through the use of highly directional links that will be used to overcome the large pathloss at these frequencies. Although the terrestrial application of mmWave systems is advancing at a rapid pace, the use of mmWave communication systems in aviation systems or airports is still in its infancy. This can be attributed to the challenges related to radio technology and lack of development, and characterization of mmWave wireless channels for the aviation field and the airport environment. Consequently, one of our goals is to develop methodologies that support mmWave air to ground links, and various links at airports, by applying new localization schemes that allow for application of highly directional links that can be deployed over longer distances despite the high path loss at mmWave frequencies. However, a very thorough understanding of the mmWave channel models are needed to enable such new applications. To this end, in this paper, we present a survey of the current channel models in the mmWave band. The 3-dimensional statistical channel model is also reviewed and its parameters and typical characteristics for this model are identified and computed through simulation for the Boise metropolitan area.

Medium power amplifiers covering 90 - 130 GHz for telescope local oscillators

NASA Technical Reports Server (NTRS)

Samoska, Lorene A.; Bryerton, Eric; Pukala, David; Peralta, Alejandro; Hu, Ming; Schmitz, Adele

2005-01-01

This paper describes a set of power amplifier (PA) modules containing InP High Electron Mobility Transistor (HEMT) Monolithic Millimeter-wave Integrated Circuit (MMIC) chips. The chips were designed and optimized for local oscillator sources in the 90-130 GHz band for the Atacama Large Millimeter Array telescope. The modules feature 20-45 mW of output power, to date the highest power from solid state HEMT MMIC modules above 110 GHz.

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

DTIC Science & Technology

1998-09-01

potential of the surface wave electromagnetic field; ea is the unit of the polarization vectors : ex = ela. = e2x= (qx/\\q\\)\\/L\\q\\/(ei + e0), ely... polarization basis of the incident wave: EB°=eB^(/kr), (1) where e„ is the cyclic unit vector , n = ±1, k is the wave vector . The equation describing...rectangular grid. From the direction determined by wave vector k0, the plane electromagnetic wave of linear polarization incidents onto the array. It

A large-diameter hollow-shaft cryogenic motor based on a superconducting magnetic bearing for millimeter-wave polarimetry.

PubMed

Johnson, B R; Columbro, F; Araujo, D; Limon, M; Smiley, B; Jones, G; Reichborn-Kjennerud, B; Miller, A; Gupta, S

2017-10-01

In this paper, we present the design and measured performance of a novel cryogenic motor based on a superconducting magnetic bearing (SMB). The motor is tailored for use in millimeter-wave half-wave plate (HWP) polarimeters, where a HWP is rapidly rotated in front of a polarization analyzer or polarization-sensitive detector. This polarimetry technique is commonly used in cosmic microwave background polarization studies. The SMB we use is composed of fourteen yttrium barium copper oxide (YBCO) disks and a contiguous neodymium iron boron (NdFeB) ring magnet. The motor is a hollow-shaft motor because the HWP is ultimately installed in the rotor. The motor presented here has a 100 mm diameter rotor aperture. However, the design can be scaled up to rotor aperture diameters of approximately 500 mm. Our motor system is composed of four primary subsystems: (i) the rotor assembly, which includes the NdFeB ring magnet, (ii) the stator assembly, which includes the YBCO disks, (iii) an incremental encoder, and (iv) the drive electronics. While the YBCO is cooling through its superconducting transition, the rotor is held above the stator by a novel hold and release mechanism. The encoder subsystem consists of a custom-built encoder disk read out by two fiber optic readout sensors. For the demonstration described in this paper, we ran the motor at 50 K and tested rotation frequencies up to approximately 10 Hz. The feedback system was able to stabilize the rotation speed to approximately 0.4%, and the measured rotor orientation angle uncertainty is less than 0.15°. Lower temperature operation will require additional development activities, which we will discuss.

A large-diameter hollow-shaft cryogenic motor based on a superconducting magnetic bearing for millimeter-wave polarimetry

NASA Astrophysics Data System (ADS)

Johnson, B. R.; Columbro, F.; Araujo, D.; Limon, M.; Smiley, B.; Jones, G.; Reichborn-Kjennerud, B.; Miller, A.; Gupta, S.

2017-10-01

In this paper, we present the design and measured performance of a novel cryogenic motor based on a superconducting magnetic bearing (SMB). The motor is tailored for use in millimeter-wave half-wave plate (HWP) polarimeters, where a HWP is rapidly rotated in front of a polarization analyzer or polarization-sensitive detector. This polarimetry technique is commonly used in cosmic microwave background polarization studies. The SMB we use is composed of fourteen yttrium barium copper oxide (YBCO) disks and a contiguous neodymium iron boron (NdFeB) ring magnet. The motor is a hollow-shaft motor because the HWP is ultimately installed in the rotor. The motor presented here has a 100 mm diameter rotor aperture. However, the design can be scaled up to rotor aperture diameters of approximately 500 mm. Our motor system is composed of four primary subsystems: (i) the rotor assembly, which includes the NdFeB ring magnet, (ii) the stator assembly, which includes the YBCO disks, (iii) an incremental encoder, and (iv) the drive electronics. While the YBCO is cooling through its superconducting transition, the rotor is held above the stator by a novel hold and release mechanism. The encoder subsystem consists of a custom-built encoder disk read out by two fiber optic readout sensors. For the demonstration described in this paper, we ran the motor at 50 K and tested rotation frequencies up to approximately 10 Hz. The feedback system was able to stabilize the rotation speed to approximately 0.4%, and the measured rotor orientation angle uncertainty is less than 0.15°. Lower temperature operation will require additional development activities, which we will discuss.

Velocity modulation spectroscopy of molecular ions II: The millimeter/submillimeter-wave spectrum of TiF + ( X3Φr)

NASA Astrophysics Data System (ADS)

Halfen, D. T.; Ziurys, L. M.

2006-11-01

The pure rotational spectrum of the molecular ion TiF + in its 3Φr ground state has been measured in the range 327-542 GHz using millimeter-wave direct absorption techniques combined with velocity modulation spectroscopy. TiF + was made in an AC discharge from a mixture of TiCl 4, F 2 in He, and argon. Ten transitions of this ion were recorded. In every transition, fluorine hyperfine interactions, as well as the fine structure splittings, were resolved. The fine structure pattern was found to be regular with almost equal spacing in frequency between the three spin components, in contrast to TiCl +, which is perturbed in the ground state. The data were fit with a case ( a) Hamiltonian and rotational, fine structure, and hyperfine constants were determined. The bond length established for TiF +, r0 = 1.7775 Å, was found to be shorter than that of TiF, r0 = 1.8342 Å—also established from mm-wave data. The hyperfine parameters determined are consistent with a δ1π1 electron configuration with the electrons primarily located on the titanium nucleus. The nuclear spin-orbit constant a indicates that the unpaired electrons are closer to the fluorine nucleus in TiF + relative to TiF, as expected with the decrease in bond length for the ion. The shorter bond distance is thought to arise from increased charge on the titanium nucleus as a result of a Ti 2+F - configuration. A similar decrease in bond length was found for TiCl + relative to TiCl.

Effects of Millimeter-Wave Electromagnetic Radiation on the Experimental Model of Migraine.

PubMed

Sivachenko, I B; Medvedev, D S; Molodtsova, I D; Panteleev, S S; Sokolov, A Yu; Lyubashina, O A

2016-02-01

Effects of millimeter-wave electromagnetic radiation (40 GHz frequency, 0.01 mW power) on the spontaneous fi ring of convergent neurons of the spinal trigeminal nucleus and their responses to electrical stimulation of the dura mater were studied in neurophysiological experiments on rats. Irradiation of the area of cutaneous receptive fields of spinal trigeminal nucleus reversibly inhibited both spontaneous discharges and activity induced by electrical stimulation of the dura mater. The second and third exposures to electromagnetic radiation with an interval of 10 min were ineffective. These results suggest that suppression of neuronal excitability in the spinal trigeminal ganglion can be a mechanism of the anti-migraine effects of electromagnetic radiation observed in clinical practice.

Multi-sensor millimeter-wave system for hidden objects detection by non-collaborative screening

NASA Astrophysics Data System (ADS)

Zouaoui, Rhalem; Czarny, Romain; Diaz, Frédéric; Khy, Antoine; Lamarque, Thierry

2011-05-01

In this work, we present the development of a multi-sensor system for the detection of objects concealed under clothes using passive and active millimeter-wave (mmW) technologies. This study concerns both the optimization of a commercial passive mmW imager at 94 GHz using a phase mask and the development of an active mmW detector at 77 GHz based on synthetic aperture radar (SAR). A first wide-field inspection is done by the passive imager while the person is walking. If a suspicious area is detected, the active imager is switched-on and focused on this area in order to obtain more accurate data (shape of the object, nature of the material ...).

Development and Implementation of Nationally Recognized Laboratory for Material Characterization in the Microwave and Millimeter Wave Bands

NASA Technical Reports Server (NTRS)

Hepburn, Frank L.; Russell, Samuel S.

2010-01-01

This report provides a progress update for establishing a laboratory for material characterization in the microwave and millimeter wave bands. During the launch of STS-124 a large area of refractory bricks was liberated from the flame trench built for the exhaust of the solid rocket motors (SRM). The inspection of the liberated area revealed many defects, debonds, corrosion and voids that are a cause for concern relating to the health of the entire flame trench wall. A request for assistance was received for the nondestructive evaluation (NDE) of these anomalies behind the refractory bricks, with the primary interest being a health assessment based on the quality of the brick, epoxy and concrete bond.

The advanced cosmic microwave explorer - A millimeter-wave telescope and stabilized platform

NASA Technical Reports Server (NTRS)

Meinhold, P. R.; Chingcuanco, A. O.; Gundersen, J. O.; Schuster, J. A.; Seiffert, M. D.; Lubin, P. M.; Morris, D.; Villela, T.

1993-01-01

We have developed and flown a 1 m diameter Gregorian telescope system for measurements of anisotropy in the Cosmic Background Radiation (CBR). The telescope is incorporated in a balloon-borne stabilized platform with arcminute stabilization capability. To date, the system has flown four times and observed from the ground at the South Pole twice. The telescope has used both coherent and incoherent detectors. We describe the development of the telescope, pointing platform, and one of the receivers employed in making measurements of the CBR. Performance of the system during the first flight and operation on the ground at the South Pole are described, and the quality of the South Pole as a millimeter wave observing site is discussed.

High-temperature superconductor antenna investigations

NASA Technical Reports Server (NTRS)

Karasack, Vincent G.

1990-01-01

The use of superconductors to increase antenna radiation efficiency and gain is examined. Although the gain of all normal-metal antennas can be increased through the use of superconductors, some structures have greater potential for practical improvement than others. Some structures suffer a great degradation in bandwidth when replaced with superconductors, while for others the improvement in efficiency is trivial due to the minimal contribution of the conductor loss mechanism to the total losses, or the already high efficiency of the structure. The following antennas and related structures are discussed: electrically small antennas, impedance matching of antennas, microstrip antennas, microwave and millimeter-wave antenna arrays, and superdirective arrays. The greatest potential practical improvements occur for large microwave and millimeter-wave arrays and the impedance matching of antennas.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doménech, J. L.; Herrero, V. J.; Tanarro, I.

The chloroniumyl cation, HCl{sup +}, has been recently identified in space from Herschel 's spectra. A joint analysis of extensive vis-UV spectroscopy emission data together with a few high-resolution and high-accuracy millimeter-wave data provided the necessary rest frequencies to support the astronomical identification. Nevertheless, the analysis did not include any infrared (IR) vibration–rotation data. Furthermore, with the end of the Herschel mission, IR observations from the ground may be one of the few available means to further study this ion in space. In this work, we provide a set of accurate rovibrational transition wavenumbers, as well as a new andmore » improved global fit of vis-UV, IR, and millimeter-wave spectroscopy laboratory data, that will aid in future studies of this molecule.« less

Ferrite film growth on semiconductor substrates towards microwave and millimeter wave integrated circuits

NASA Astrophysics Data System (ADS)

Chen, Z.; Harris, V. G.

2012-10-01

It is widely recognized that as electronic systems' operating frequency shifts to microwave and millimeter wave bands, the integration of ferrite passive devices with semiconductor solid state active devices holds significant advantages in improved miniaturization, bandwidth, speed, power and production costs, among others. Traditionally, ferrites have been employed in discrete bulk form, despite attempts to integrate ferrite as films within microwave integrated circuits. Technical barriers remain centric to the incompatibility between ferrite and semiconductor materials and their processing protocols. In this review, we present past and present efforts at ferrite integration with semiconductor platforms with the aim to identify the most promising paths to realizing the complete integration of on-chip ferrite and semiconductor devices, assemblies and systems.

Epoxy-based broadband antireflection coating for millimeter-wave optics.

PubMed

Rosen, Darin; Suzuki, Aritoki; Keating, Brian; Krantz, William; Lee, Adrian T; Quealy, Erin; Richards, Paul L; Siritanasak, Praween; Walker, William

2013-11-20

We have developed epoxy-based, broadband antireflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixing three types of epoxy and doping with strontium titanate powder required for the high dielectric mixtures. At 140 K, the band-integrated absorption loss in the coatings was suppressed to less than 1% for the two-layer coating, and below 10% for the three-layer coating.

[The influence of low-energy millimeter electromagnetic waves on the stability of DNA molecules in solution].

PubMed

Babaian; Markarian, A Sh; Kalantarian, V P; Kazarian, R S; Parsadanian, M A; Vardevanian, P O

2007-01-01

The influence of low-energy millimeter electromagnetic waves on aqueous saline solution of DNA from the liver of healthy rats and rats with sarcoma 45 has been investigated. The characteristic parameters of irradiated and unirradiated DNA, melting temperature, and the range of melting were obtained from melting curves. The duration of exposure did not practically affect the range of melting, while the thermostability of DNA increased; as irradiation duration increased to 90 min, the melting temperature of tumor increased by approximately 1.5 degrees C. It was assumped that the increase in the thermostability of DNA is due to a more effective stabilization of the DNA double helix caused by the dehydration of Na(+)- ions present in the solution.

Design and construction of prototype radio antenna for shortest radio wavelengths

NASA Technical Reports Server (NTRS)

Leighton, R. B.

1975-01-01

A paraboloid radio antenna of 10.4 meters diameter, 0.41 meter focal length was constructed and its successful completion is described. The surface accuracy of the antenna is at least four times better than any existing antenna in its class size (50 micrometers rms). Antenna design specifications (i.e., for mounting, drive motors, honeycomb structures) are discussed and engineering drawings and photographs of antenna components are shown. The antenna will be used for millimeter-wave interferometry and sub-millimeter wave radiometry over a full frequency range (up to approximately 860 GHz). The antenna will also be moveable (for interferometric use) between reinforced concrete pads by rail. The effects of the weather and gravity on antenna performance are briefly discussed.

Millimeter/Submillimeter Spectroscopy of TiO (X3Δr): The Rare Titanium Isotopologues

NASA Astrophysics Data System (ADS)

Lincowski, A. P.; Halfen, D. T.; Ziurys, L. M.

2016-12-01

Pure rotational spectra of the rare isotopologues of titanium oxide, 46TiO, 47TiO, 49TiO, and 50TiO, have been recorded using a combination of Fourier transform millimeter-wave (FTmmW) and millimeter/submillimeter direct absorption techniques in the frequency range 62-538 GHz. This study is the first complete spectroscopic characterization of these species in their X 3Δ r ground electronic states. The isotopologues were created by the reaction of N2O or O2 and titanium vapor, produced either by laser ablation or in a Broida-type oven, and observed in the natural Ti isotopic abundances. Between 10 and 11 rotational transitions J + 1 ≤ftrightarrow J were measured for each species, typically in all 3 spin-orbit ladders Ω = 1, 2, and 3. For 47TiO and 49TiO, hyperfine structure was resolved, originating from the titanium-47 and titanium-49 nuclear spins of I = 5/2 and 7/2, respectively. For the Ω = 1 and 3 components, the hyperfine structure was found to follow a classic Landé pattern, while that for Ω = 2 appeared to be perturbed, likely a result of mixing with the nearby isoconfigurational a 1Δ state. The spectra were analyzed with a case (a) Hamiltonian, and rotational, spin-orbit, and spin-spin parameters were determined for each species, as well as magnetic hyperfine and electric quadrupole constants for the two molecules with nuclear spins. The most abundant species, 48TiO, has been detected in circumstellar envelopes. These measurements will enable other titanium isotopologues to be studied at millimeter wavelengths, providing Ti isotope ratios that can test models of nucleosynthesis.

The Effect of Clouds on Water Vapor Profiling from the Millimeter-Wave Radiometric Measurements

NASA Technical Reports Server (NTRS)

Wang, J. R.; Spinhirne, J. D.; Racette, P.; Chang, L. A.; Hart, W.

1997-01-01

Simultaneous measurements with the millimeter-wave imaging radiometer (MIR), cloud lidar system (CLS), and the MODIS airborne simulator (MAS) were made aboard the NASA ER-2 aircraft over the western Pacific Ocean on 17-18 January 1993. These measurements were used to study the effects of clouds on water vapor profile retrievals based on millimeter-wave radiometer measurements. The CLS backscatter measurements (at 0.532 and 1.064 am) provided information on the heights and a detailed structure of cloud layers; the types of clouds could be positively identified. All 12 MAS channels (0.6-13 Am) essentially respond to all types of clouds, while the six MIR channels (89-220 GHz) show little sensitivity to cirrus clouds. The radiances from the 12-/Am and 0.875-gm channels of the MAS and the 89-GHz channel of the MIR were used to gauge the performance of the retrieval of water vapor profiles from the MIR observations under cloudy conditions. It was found that, for cirrus and absorptive (liquid) clouds, better than 80% of the retrieval was convergent when one of the three criteria was satisfied; that is, the radiance at 0.875 Am is less than 100 W/cm.sr, or the brightness at 12 Am is greater than 260 K, or brightness at 89 GHz is less than 270 K (equivalent to cloud liquid water of less than 0.04 g/cm). The range of these radiances for convergent retrieval increases markedly when the condition for convergent retrieval was somewhat relaxed. The algorithm of water vapor profiling from the MIR measurements could not perform adequately over the areas of storm-related clouds that scatter radiation at millimeter wavelengths.

The Rotational Spectrum of Anti-Ethylamine (CH3CH2NH2) from 10 to 270 GHz: A Laboratory Study and Astronomical Search in Sgr B2(N)

NASA Astrophysics Data System (ADS)

Apponi, A. J.; Sun, M.; Halfen, D. T.; Ziurys, L. M.; Müller, H. S. P.

2008-02-01

The pure rotational spectrum of the lowest energy (anti-) conformer of ethylamine (CH3CH2NH2) has been measured in the frequency range of 10-270 GHz. The spectrum was recorded using both millimeter-wave absorption spectroscopy and Fourier transform microwave (FTMW) techniques. Ten rotational transitions of this molecule were recorded in the frequency range of 10-40 GHz using FTMW methods, resulting in the assignment of 53 quadrupole-resolved hyperfine lines; in the millimeter-wave region (48-270 GHz), nearly 600 transitions were assigned to the ground (anti-) state. The amine group in CH3CH2NH2 undergoes inversion, resulting in a doubling that is frequently small and most apparent in the low-frequency K-doubling transitions. In addition, seemingly random rotational levels of this molecule were found to be significantly perturbed. The cause of these perturbations is presently uncertain, but torsion-rotation interactions with the higher lying gauche conformers seem to be a likely explanation. An astronomical search was conducted for ethylamine toward Sgr B2(N) using the Kitt Peak 12 m antenna and the Sub-Millimeter Telescope (SMT) of the Arizona Radio Observatory. Frequencies of 70 favorable rotational transitions were observed in this search, which covered the range 68-263 GHz. Ethylamine was not conclusively detected in Sgr B2(N), with an upper limit to the column density of (1-8) × 1013 cm-2 with f(CH3CH2NH2/H2) ~ (0.3-3) × 10-11, assuming a rotational temperature of 50-220 K. These observations indicate a gas-phase CH3CH2NH2/CH3NH2 ratio of <0.001-0.01, in contrast to the nearly equal ratio suggested by the acid hydrolysis of cometary solids from the Stardust mission.

Multi-Bandwidth Frequency Selective Surfaces for Near Infrared Filtering: Design and Optimization

NASA Technical Reports Server (NTRS)

Cwik, Tom; Fernandez, Salvador; Ksendzov, A.; LaBaw, Clayton C.; Maker, Paul D.; Muller, Richard E.

1999-01-01

Frequency selective surfaces are widely used in the microwave and millimeter wave regions of the spectrum for filtering signals. They are used in telecommunication systems for multi-frequency operation or in instrument detectors for spectroscopy. The frequency selective surface operation depends on a periodic array of elements resonating at prescribed wavelengths producing a filter response. The size of the elements is on the order of half the electrical wavelength, and the array period is typically less than a wavelength for efficient operation. When operating in the optical region, diffraction gratings are used for filtering. In this regime the period of the grating may be several wavelengths producing multiple orders of light in reflection or transmission. In regions between these bands (specifically in the infrared band) frequency selective filters consisting of patterned metal layers fabricated using electron beam lithography are beginning to be developed. The operation is completely analogous to surfaces made in the microwave and millimeter wave region except for the choice of materials used and the fabrication process. In addition, the lithography process allows an arbitrary distribution of patterns corresponding to resonances at various wavelengths to be produced. The design of sub-millimeter filters follows the design methods used in the microwave region. Exacting modal matching, integral equation or finite element methods can be used for design. A major difference though is the introduction of material parameters and thicknesses tha_ may not be important in longer wavelength designs. This paper describes the design of multi-bandwidth filters operating in the I-5 micrometer wavelength range. This work follows on previous design [1,2]. In this paper extensions based on further optimization and an examination of the specific shape of the element in the periodic cell will be reported. Results from the design, manufacture and test of linear wedge filters built using micro-lithographic techniques and used ir spectral imaging applications will be presented.

Multi-Bandwidth Frequency Selective Surfaces for Near Infrared Filtering: Design and Optimization

NASA Technical Reports Server (NTRS)

Cwik, Tom; Fernandez, Salvador; Ksendzov, A.; LaBaw, Clayton C.; Maker, Paul D.; Muller, Richard E.

1998-01-01

Frequency selective surfaces are widely used in the microwave and millimeter wave regions of the spectrum for filtering signals. They are used in telecommunication systems for multi-frequency operation or in instrument detectors for spectroscopy. The frequency selective surface operation depends on a periodic array of elements resonating at prescribed wavelengths producing a filter response. The size of the elements is on the order of half the electrical wavelength, and the array period is typically less than a wavelength for efficient operation. When operating in the optical region, diffraction gratings are used for filtering. In this regime the period of the grating may be several wavelengths producing multiple orders of light in reflection or transmission. In regions between these bands (specifically in the infrared band) frequency selective filters consisting of patterned metal layers fabricated using electron beam lithography are beginning to be developed. The operation is completely analogous to surfaces made in the microwave and millimeter wave region except for the choice of materials used and the fabrication process. In addition, the lithography process allows an arbitrary distribution of patterns corresponding to resonances at various wavelengths to be produced. The design of sub-millimeter filters follows the design methods used in the microwave region. Exacting modal matching, integral equation or finite element methods can be used for design. A major difference though is the introduction of material parameters and thicknesses that may not be important in longer wavelength designs. This paper describes the design of multi- bandwidth filters operating in the 1-5 micrometer wavelength range. This work follows on a previous design. In this paper extensions based on further optimization and an examination of the specific shape of the element in the periodic cell will be reported. Results from the design, manufacture and test of linear wedge filters built using microlithographic techniques and used in spectral imaging applications will be presented.

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.

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.

Radio-over-fiber system with octuple frequency optical millimeter-wave signal generation using dual-parallel Mach-Zehnder modulator based on four-wave mixing in semiconductor optical amplifier

NASA Astrophysics Data System (ADS)

Zhou, Hui; Zeng, Yuting; Chen, Ming; Shen, Yunlong

2018-03-01

We have proposed a scheme of radio-over-fiber (RoF) system employing a dual-parallel Mach-Zehnder modulator (DP-MZM) based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). In this scheme, the pump and the signal are generated by properly adjusting the direct current bias, modulation index of the DP-MZM, and the phase difference between the sub-MZMs. Because of the pump and the signal deriving from the same optical wave, the polarization states of the two lightwaves are copolarized. The single-pump FWM is polarization insensitive. After FWM and optical filtering, the optical millimeter-wave with octuple frequency is generated. About 40-GHz RoF system with a 2.5-Gbit / s signal is implemented by numerical simulation; the result shows that it has a good performance after the signal is transmitted over 40-km single-mode fiber. Then, the effects of the SOA's injection current and the carrier-to-sideband ratio on the system performance are discussed by simulation, and the optimum value for the system is obtained.

Laboratory measurements of the millimeter-wave spectra of calcium isocyanide

NASA Astrophysics Data System (ADS)

Steimle, Timothy C.; Saito, Shuji; Takano, Shuro

1993-06-01

The ground state of CaNC is presently characterized by mm-wave spectroscopy, using a standard Hamiltonian linear molecule model to analyze the spectrum. The resulting spectroscopic parameters were used to predict the transition frequencies and Einstein A-coefficients, which should make possible a quantitative astrophysical search for CaNC.

3D-Printed Millimeter Wave Structures

DTIC Science & Technology

2016-03-14

demonstrates the resolution of the printer with a 10 micron nozzle. Figure 2: Measured loss tangent of SEBS and SBS samples. 3D - Printed Millimeter... 3D printing of styrene-butadiene-styrene (SBS) and styrene ethylene/butylene-styrene (SEBS) is used to demonstrate the feasibility of 3D - printed ...Additionally, a dielectric lens is printed which improves the antenna gain of an open-ended WR-28 waveguide from 7 to 8.5 dBi. Keywords: 3D printing

Studies of Millimeter-Wave Diffraction Devices and Materials

DTIC Science & Technology

1984-12-28

7.0 REFERENCES 1. Andrenko, S . d., Devyatkov, Acad. N. D., and Shestopalov, V. P., "Millimeter Field Band Antenna Arrays", Dokl. Akad. 4auk SSSR, Vol... S UNCLASSTFIED I* .RIT.Y CL.ASSIFICATION OF THIS PAGE REPORT DOCUMENTATION PAGE :kFPOO- SEURITY CLASSIFICATION 1-b. RESTRICTIVE MARKINGS .EM...State and ZIP Code) 10. SOURCE OF FUNDIN.G NOS. ______ C)c \\~ S PROGRAM PROJECT TASK WORK UNIT 2~~V \\~ ~(~ELEMENT NO. NO. No. NO. ATEinciude Security

Millimeter radiometer system technology

NASA Technical Reports Server (NTRS)

Wilson, W. J.; Swanson, P. N.

1989-01-01

JPL has had a large amount of experience with spaceborne microwave/millimeter wave radiometers for remote sensing. All of the instruments use filled aperture antenna systems from 5 cm diameter for the microwave Sounder Units (MSU), 16 m for the microwave limb sounder (MLS) to 20 m for the large deployable reflector (LDR). The advantages of filled aperture antenna systems are presented. The requirements of the 10 m Geoplat antenna system, 10 m multified antenna, and the MLS are briefly discussed.

Millimeter radiometer system technology

NASA Astrophysics Data System (ADS)

Wilson, W. J.; Swanson, P. N.

1989-07-01

JPL has had a large amount of experience with spaceborne microwave/millimeter wave radiometers for remote sensing. All of the instruments use filled aperture antenna systems from 5 cm diameter for the microwave Sounder Units (MSU), 16 m for the microwave limb sounder (MLS) to 20 m for the large deployable reflector (LDR). The advantages of filled aperture antenna systems are presented. The requirements of the 10 m Geoplat antenna system, 10 m multified antenna, and the MLS are briefly discussed.

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.

De-embedding technique for accurate modeling of compact 3D MMIC CPW transmission lines

NASA Astrophysics Data System (ADS)

Pohan, U. H.; KKyabaggu, P. B.; Sinulingga, E. P.

2018-02-01

Requirement for high-density and high-functionality microwave and millimeter-wave circuits have led to the innovative circuit architectures such as three-dimensional multilayer MMICs. The major advantage of the multilayer techniques is that one can employ passive and active components based on CPW technology. In this work, MMIC Coplanar Waveguide(CPW)components such as Transmission Line (TL) are modeled in their 3D layouts. Main characteristics of CPWTL suffered from the probe pads’ parasitic and resonant frequency effects have been studied. By understanding the parasitic effects, then the novel de-embedding technique are developed accurately in order to predict high frequency characteristics of the designed MMICs. The novel de-embedding technique has shown to be critical in reducing the probe pad parasitic significantly from the model. As results, high frequency characteristics of the designed MMICs have been presented with minimumparasitic effects of the probe pads. The de-embedding process optimises the determination of main characteristics of Compact 3D MMIC CPW transmission lines.

Sound Waves Levitate Substrates

NASA Technical Reports Server (NTRS)

Lee, M. C.; Wang, T. G.

1982-01-01

System recently tested uses acoustic waves to levitate liquid drops, millimeter-sized glass microballoons, and other objects for coating by vapor deposition or capillary attraction. Cylindrical contactless coating/handling facility employs a cylindrical acoustic focusing radiator and a tapered reflector to generate a specially-shaped standing wave pattern. Article to be processed is captured by the acoustic force field under the reflector and moves as reflector is moved to different work stations.

Transmission characteristic of graphene/TiO2 paper measured at Ka-band

NASA Astrophysics Data System (ADS)

Agusu, La; Mitsudo, Seitaro; Ahmad, La Ode; Herdianto, Fujii, Yutaka; Ishikawa, Yuya; Furuya, Takahashi; Ramadhan, La Ode Ahmad Nur

2017-01-01

The commercial telecommunication system in future would explore the electromagnetic spectrum with higher frequency than used now, because it requires higher speed of transmission data. Using the millimeter waves (mmW) with frequency ranging from 30 to 300 GHz, such requirement could be fulfilled. The upcoming 5G cellular technology is expected to use frequency 30 GHz or higher. Then materials with a specific characteristic at the mmW range are interesting to be explored and investigated. Here, we report the synthesis process of graphene/TiO2 deposited on paper and their transmission characteristics to the electromagnetic energy at frequency 27-40 GHz (Ka-Band). The reduced graphene oxide (rGO) was synthesized by a modified Hummers method with introduction of microwave irradiation in the process. rGO and TiO2 were mixed in ethanol solution and deposited on the paper by a spraying technique. Transmission coefficient of electromagnetic wave energy at Ka-Band was measured by using the millimeter vector network analyzer. Conductivity of rGO is 1.89 Scm-1 and for the graphene/TiO2 with TiO2 content is up to 50%, conductivity is down to Scm-1 Graphene/TiO2 layer with thickness of 60).lm and TiO2 loading up to 25% can has the transmission coefficient of -4 dB at the middle frequency of 31 GHz and bandwidth of 2.2 GHz. This can be useful as the electromagnetic interference shielding material at Ka-band.

Millimeter‐wave emissivity as a metric for the non‐contact diagnosis of human skin conditions

PubMed Central

Salmon, Neil; Harmer, Stuart William; Shylo, Sergiy; Bowring, Nicholas John; Rezgui, Nacer Ddine; Shah, Mamta

2017-01-01

A half‐space electromagnetic model of human skin over the band 30–300 GHz was constructed and used to model radiometric emissivity. The model showed that the radiometric emissivity rose from 0.4 to 0.8 over this band, with emission being localized to a layer approximately one millimeter deep in the skin. Simulations of skin with differing water contents associated with psoriasis, eczema, malignancy, and thermal burn wounds indicated radiometry could be used as a non‐contact technique to detect and monitor these conditions. The skin emissivity of a sample of 30 healthy volunteers, measured using a 95 GHz radiometer, was found to range from 0.2 to 0.7, and the experimental measurement uncertainty was ±0.002. Men on average were found to have an emissivity 0.046 higher than those of women, a measurement consistent with men having thicker skin than women. The regions of outer wrist and dorsal forearm, where skin is thicker, had emissivities 0.06–0.08 higher than the inner wrist and volar forearms where skin is generally thinner. Recommendations are made to develop a more sophisticated model of the skin and to collect larger data sets to obtain a deeper understanding of the signatures of human skin in the millimeter wave band. Bioelectromagnetics. 38:559–569, 2017. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. PMID:28836682

Realization of a video-rate distributed aperture millimeter-wave imaging system using optical upconversion

NASA Astrophysics Data System (ADS)

Schuetz, Christopher; Martin, Richard; Dillon, Thomas; Yao, Peng; Mackrides, Daniel; Harrity, Charles; Zablocki, Alicia; Shreve, Kevin; Bonnett, James; Curt, Petersen; Prather, Dennis

2013-05-01

Passive imaging using millimeter waves (mmWs) has many advantages and applications in the defense and security markets. All terrestrial bodies emit mmW radiation and these wavelengths are able to penetrate smoke, fog/clouds/marine layers, and even clothing. One primary obstacle to imaging in this spectrum is that longer wavelengths require larger apertures to achieve the resolutions desired for many applications. Accordingly, lens-based focal plane systems and scanning systems tend to require large aperture optics, which increase the achievable size and weight of such systems to beyond what can be supported by many applications. To overcome this limitation, a distributed aperture detection scheme is used in which the effective aperture size can be increased without the associated volumetric increase in imager size. This distributed aperture system is realized through conversion of the received mmW energy into sidebands on an optical carrier. This conversion serves, in essence, to scale the mmW sparse aperture array signals onto a complementary optical array. The side bands are subsequently stripped from the optical carrier and recombined to provide a real time snapshot of the mmW signal. Using this technique, we have constructed a real-time, video-rate imager operating at 75 GHz. A distributed aperture consisting of 220 upconversion channels is used to realize 2.5k pixels with passive sensitivity. Details of the construction and operation of this imager as well as field testing results will be presented herein.

Novel Low-Cost, Low-Power Miniature Thermionic Cathode Developed for Microwave/Millimeter Wave Tube and Cathode Ray Tube Applications

NASA Technical Reports Server (NTRS)

Wintucky, Edwin G.

1999-01-01

A low cost, small size and mass, low heater power, durable high-performance barium dispenser thermionic cathode has been developed that offers significant advancements in the design, manufacture, and performance of the electron sources used in vacuum electronic devices--such as microwave (and millimeter wave) traveling-wave tubes (TWT's)--and in display devices such as high-brightness, high-resolution cathode ray tubes (CRT's). The lower cathode heater power and the reduced size and mass of the new cathode are expected to be especially beneficial in TWT's for deep space communications, where future missions are requiring smaller spacecraft, higher data transfer rates (higher frequencies and radiofrequency output power), and greater electrical efficiency. Also expected to benefit are TWT's for commercial and government communication satellites, for both low and geosynchronous Earth orbit, with additional benefits offered by lower cost and potentially higher cathode current loading. A particularly important TWT application is in the microwave power module (MPM), which is a hybrid microwave (or millimeter wave) amplifier consisting of a low-noise solid state driver, a vacuum power booster (small TWT), and an electronic power conditioner integrated into a single compact package. The attributes of compactness and potentially high electrical efficiency make the MPM very attractive for many commercial and government (civilian and defense) applications in communication and radar systems. The MPM is already finding application in defense electronic systems and is under development by NASA for deep space communications. However, for the MPM to become competitive and commercially successful, a major reduction in cost must be achieved.

Vibrational Population Distribution in Formaldehyde Expanding from Chen Pyrolysis Nozzle Measured by Chirped Pulse Millimeter Wave Spectroscopy

NASA Astrophysics Data System (ADS)

Kuyanov-Prozument, Kirill; Vasiliou, Angayle; Park, G. Barratt; Muenter, John S.; Stanton, John F.; Ellison, G. Barney; Field, Robert W.

2011-06-01

Knowing the vibrational population distribution of unimolecular fragmentation reaction products can reveal the reaction mechanism. Here, we applied Chirped Pulse Millimeter Wave (CPmmW) spectroscopy, invented by Brooks Pate and co-workers, to detect the vibrational population distribution of formaldehyde produced by pyrolysis of methyl nitrite (CH_3ONO) or ethyl nitrite (CH_3CH_2ONO). The pure rotational spectrum contains information about vibrational populations via the known vibration dependence of the rotational constants, which is easily observed in the millimeter-wave spectrum. Only two of six vibrational modes of formaldehyde are significantly populated in both pyrolysis decomposition reactions and in an expansion of pure formaldehyde, suggesting that it is the collisional energy transfer that primarily determines the vibrational population distribution. The non-Boltzmann population distribution among the observed vibrational modes demonstrates non-statistical vibrational energy transfer in formaldehyde. It is in sharp contrast with the equilibrated population distribution measured in OCS and the almost complete vibrational relaxation observed in acetaldehyde. This work is supported by grants from the US Department of Energy and the ACS Petroleum Research Fund, and the National Science Foundation grant "Organic Radicals in Biomass Decomposition: Mechanisms & Dynamics," (CHE-0848606) G. G. Brown, B. C. Dian, K. O. Douglass, S. M. Geyer, S. T. Shipman and B. H. Pate Rev. Sci. Instrum. 79, 053103 (1995).

Characteristics of ocular temperature elevations after exposure to quasi- and millimeter waves (18-40 GHz)

NASA Astrophysics Data System (ADS)

Kojima, Masami; Suzuki, Yukihisa; Tsai, Cheng-Yu; Sasaki, Kensuke; Wake, Kanako; Watanabe, Soichi; Taki, Masao; Kamimura, Yoshitsugu; Hirata, Akimasa; Sasaki, Kazuyuki; Sasaki, Hiroshi

2015-04-01

In order to investigate changes in ocular temperature in rabbit eyes exposed to different frequencies (18 to 40 GHz) of quasi-millimeter waves, and millimeter waves (MMW). Pigmented rabbits were anesthetized with both general and topical anesthesia, and thermometer probes (0.5 mm in diameter) were inserted into their cornea (stroma), lens (nucleus) and vitreous (center of vitreous). The eyes were exposed unilaterally to 200 mW/cm2 by horn antenna for 3 min at 18, 22 and 26.5 GHz using a K band exposure system or 26.5, 35 and 40 GHz using a Ka band exposure system. Changes in temperature of the cornea, lens and vitreous were measured with a fluoroptic thermometer. Since the ocular temperatures after exposure to 26.5 GHz generated by the K band and Ka band systems were similar, we assumed that experimental data from these 2 exposure systems were comparable. The highest ocular temperature was induced by 40 GHz MMW, followed by 35 GHz. The 26.5 and 22 GHz corneal temperatures were almost the same. The lowest temperature was recorded at 18 GHz. The elevation in ocular temperature in response to exposure to 200 mW/cm2 MMW is dependent on MMW frequency. MMW exposure induced heat is conveyed not only to the cornea but also the crystalline lens.

Damping of surface waves due to oil emulsions in application to ocean remote sensing

NASA Astrophysics Data System (ADS)

Sergievskaya, I.; Ermakov, S.; Lazareva, T.; Lavrova, O.

2017-10-01

Applications of different radar and optical methods for detection of oil pollutions based on the effect of damping of short wind waves by surface films have been extensively studied last decades. The main problem here is poor knowledge of physical characteristics of oil films, in particular, emulsified oil layers (EOL). The latter are ranged up to 70% of all pollutants. Physical characteristics of EOL which are responsible for wave damping and respectively for possibilities of their remote sensing depend on conditions of emulsification processes, e.g., mixing due to wave breaking, on percentage of water in the oil, etc. and are not well studied by now. In this paper results of laboratory studies of damping of gravity-capillary waves due to EOL on water are presented and compared to oil layers (OL). A laboratory method used previously for monomolecular films and OL, and based on measuring the damping coefficient and wavelength of parametrically generated standing waves has been applied for determination of EOL characteristics. Investigations of characteristics of crude oil, oil emulsions and crude OL and EOL have been carried out in a wide range of surface wave frequencies (from 10 to 25 Hz) and OL and EOL film thickness (from hundredths of millimeter to a few millimeters. The selected frequency range corresponds to Bragg waves for microwave, X- to Ka-band radars typically used for ocean remote sensing. An effect of enhanced wave damping due to EOL compared to non emulsified crude OL is revealed.

Second Beamed Space-Power Workshop

NASA Technical Reports Server (NTRS)

Deyoung, Russell J. (Editor)

1989-01-01

Potential missions for microwave and laser power beaming in space are discussed. Power beaming options, millimeter wave technology, laser technology, lunar bases, spacecraft propulsion, and near-Earth applications are covered.

Lunar Radio_phase Ranging in Chinese Lunar Lander Mission for Astrometry

NASA Astrophysics Data System (ADS)

Ping, Jinsong; Meng, Qiao; Li, Wenxiao; Wang, Mingyuan; Wang, Zhen; Zhang, Tianyi; Han, Songtao

2015-08-01

The radio tracking data in lunar and planetary missions can be directly applied for scientific investigation. The variations of phase and of amplitude of the radio carrier wave signal linked between the spacecraft and the ground tracking antenna are used to deduce the planetary atmospheric and ionospheric structure, planetary gravity field, mass, ring, ephemeris, and even to test the general relativity. In the Chinese lunar missions, we developed the lunar and planetary radio science receiver to measure the distance variation between the tracking station-lander by means of open loop radio phase tracking. Using this method in Chang’E-3 landing mission, a lunar radio_phase ranging (LRR) technique was realized at Chinese deep space tracking stations and astronomical VLBI stations with H-maser clocks installed. Radio transponder and transmitter had been installed on the Chang’E-3/4. Transponder will receive the uplink S/X band radio wave transmitted from the two newly constructed Chinese deep space stations, where the high quality hydrogen maser atomic clocks have been used as local time and frequency standard. The clocks between VLBI stations and deep space stations can be synchronized to UTC standard within 20 nanoseconds using satellite common view methods. In the near future there will be a plan to improve this accuracy to 5 nanoseconds or better, as the level of other deep space network around world. In the preliminary LRR experiments of Chang'E-3, the obtained 1sps phase ranging observables have a resolution of 0.2 millimeter or better, with a fitting RMS about 2~3 millimeter, after the atmospheric and ionospheric errors removed. This method can be a new astrometric technique to measure the Earth tide and rotation, lunar orbit, tides and liberation, by means of solo observation or of working together with Lunar Laser Ranging. After differencing the ranging, we even obtained 1sps doppler series of 2-way observables with resolution of 0.07mm/second, which can be used to check the uplimit for low frequency (0.001~1 Hz) gravitational wave detection between the Earth and the Moon.

Analysis of limited-diffractive and limited-dispersive X-waves generated by finite radial waveguides

NASA Astrophysics Data System (ADS)

Fuscaldo, Walter; Pavone, Santi C.; Valerio, Guido; Galli, Alessandro; Albani, Matteo; Ettorre, Mauro

2016-05-01

In this work, we analyze the spatial and temporal features of electromagnetic X-waves propagating in free space and generated by planar radiating apertures. The performance of ideal X-waves is discussed and compared to practical cases where the important effects related to the finiteness of the radiating aperture and the wavenumber dispersion are taken into account. In particular, a practical device consisting of a radial waveguide loaded with radiating slots aligned along a spiral path is considered for the practical case in the millimeter-wave range. A common mathematical framework is defined for a precise comparison of the spatiotemporal properties and focusing capabilities of the generated X-wave. It is clearly shown that the fractional bandwidth of the radiating aperture has a key role in the longitudinal confinement of an X-wave in both ideal and practical cases. In addition, the finiteness of the radiating aperture as well as the wavenumber dispersion clearly affect both the transverse and the longitudinal profiles of the generated radiation as it travels beyond the depth-of-field of the generated X-wave. Nevertheless, the spatiotemporal properties of the X-wave are preserved even in this "dispersive-finite" case within a defined region and duration related to the nondiffractive range and fractional bandwidth of the spectral components of the generated X-wave. The proposed analysis may open new perspectives for the efficient generation of X-waves over finite radiating apertures at millimeter waves where the dispersive behavior of realistic devices is no longer negligible.