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Sample records for ghz high power

  1. 30 GHz High Power Production for CLIC

    SciTech Connect

    Syratchev, I.

    2006-01-03

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous TM01 mode at 30 GHz. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and conveyed to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability along single decelerator (600 m) and active length of the structure given by main linac RF power needs and layout. Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide reliable design.

  2. An 8-18 GHz broadband high power amplifier

    NASA Astrophysics Data System (ADS)

    Lifa, Wang; Ruixia, Yang; Jingfeng, Wu; Yanlei, Li

    2011-11-01

    An 8-18 GHz broadband high power amplifier (HPA) with a hybrid integrated circuit (HIC) is designed and fabricated. This HPA is achieved with the use of a 4-fingered micro-strip Lange coupler in a GaAs MMIC process. In order to decrease electromagnetic interference, a multilayer AlN material with good heat dissipation is adopted as the carrier of the power amplifier. When the input power is 25 dBm, the saturated power of the continuous wave (CW) outputted by the power amplifier is more than 39 dBm within the frequency range of 8-13 GHz, while it is more than 38.6 dBm within other frequency ranges. We obtain the peak power output, 39.4 dBm, at the frequency of 11.9 GHz. In the whole frequency band, the power-added efficiency is more than 18%. When the input power is 18 dBm, the small signal gain is 15.7 ± 0.7 dB. The dimensions of the HPA are 25 × 15 × 1.5 mm3.

  3. High power 303 GHz gyrotron for CTS in LHD

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Y.; Kasa, J.; Saito, T.; Tatematsu, Y.; Kotera, M.; Kubo, S.; Shimozuma, T.; Tanaka, K.; Nishiura, M.

    2015-10-01

    A high-power pulsed gyrotron is under development for 300 GHz-band collective Thomson scattering (CTS) diagnostics in the Large Helical Device (LHD). High-density plasmas in the LHD require a probe wave with power exceeding 100 kW in the sub-terahertz region to obtain sufficient signal intensity and large scattering angles. At the same time, the frequency bandwidth should be less than several tens of megahertz to protect the CTS receiver using a notch filter against stray radiations. Moreover, duty cycles of ~ 10% are desired for the time domain analysis of the CTS spectrum. At present, a 77 GHz gyrotron for electron cyclotron heating is used as a CTS wave source in the LHD. However, the use of such a low-frequency wave suffers from refraction, cutoff and absorption at the electron cyclotron resonance layer. Additionally, the signal detection is severely affected by background noise from electron cyclotron emission. To resolve those problems, high-power gyrotrons in the 300 GHz range have been developed. In this frequency range, avoiding mode competition is critical to realizing high-power and stable oscillation. A moderately over-moded cavity was investigated to isolate a desired mode from neighbouring modes. After successful tests with a prototype tube, the practical one was constructed with a cavity for TE22,2 operation mode, a triode electron gun forming intense laminar electron beams, and an internal mode convertor. We have experimentally confirmed single mode oscillation of the TE22,2 mode at the frequency of 303.3 GHz. The spectrum peak is sufficiently narrow. The output power of 290 kW has been obtained at the moment.

  4. High power testing of a 17 GHz photocathode RF gun

    SciTech Connect

    Chen, S.C.; Danly, B.G.; Gonichon, J.

    1995-12-31

    The physics and technological issues involved in high gradient particle acceleration at high microwave (RF) frequencies are under study at MIT. The 17 GHz photocathode RF gun has a 1 1/2 cell ({pi} mode) room temperature cooper cavity. High power tests have been conducted at 5-10 MW levels with 100 ns pulses. A maximum surface electric field of 250 MV/m was achieved. This corresponds to an average on-axis gradient of 150 MeV/m. The gradient was also verified by a preliminary electron beam energy measurement. Even high gradients are expected in our next cavity design.

  5. High Power Operation of a 170 GHz Gyrotron for ITER

    NASA Astrophysics Data System (ADS)

    Kreischer, Kenneth E.

    1996-11-01

    Recent experiments at MIT (In collaboration with B.G. Danly, T. Kimura, and R.J. Temkin) on a megawatt gyrotron designed for ITER have achieved record powers at 170.1 GHz. Single mode emission with a peak output power of 1.5 MW and an efficiency of 35% has been measured. The MIT gyrotron operates for 3 μsec pulses at 2 Hz but has been designed to model long pulse or cw operation. The experiment is based on a resonant cylindrical cavity operating in the TE_28,8,1 mode that is situated in the bore of a 6.7 T magnet. It is necessary to operate in a very high order mode in order to reduce cavity ohmic losses to levels that can be adequately cooled (about 1 kW/cm^2). The microwaves are generated in the cavity by an 83 kV annular electron beam produced by a triode-type magnetron injection gun that is capable of currents up to 50 A. Megawatt power levels with efficiencies between 30-35% have been measured over a wide range of operating parameters for the TE_28,8,1 mode. Similar results were also achieved in the neighboring TE_27,8,1 mode at 166.6 GHz, and the TE_29,8,1 mode at 173.5 GHz. These results are in good agreement with nonlinear multimode simulations of the cavity. (S.Y. Cai, T.M. Antonsen, G. Saraph, and B. Levush, Int. J. Electronics, Vol. 72, 759-777 (1992).) The high output power is the result of a carefully designed electron gun that is less sensitive than previous guns to misalignment, and a novel cavity that is less prone to mode competition. The gun was built by C.P.I. (formerly Varian Associates), and has a low perpendicular velocity spread (6-10%). The cavity, which was designed in collaboration with the University of Maryland, uses an output iris to increase the diffraction Q while keeping the interaction length short. Future plans include the installation of an internal mode converter that will transform the TE_28,8,1 mode into a Gaussian beam, and the use of a depressed collector to increase the device efficiency above 50%. The successful

  6. NASA seeking high-power 60-GHz IMPATT diodes

    NASA Technical Reports Server (NTRS)

    Haugland, E. J.

    1984-01-01

    Recent progress in the development of high-power 60 GHz GaAs IMPATT diodes for communication links with high-data-rate satellites is discussed. One of the advantages of GaAs over Si as the material for the diodes are that GaAs is likely to have a higher output and efficiency than Si despite recent advances in Si technology. It is therefore in GaAs technology that research is currently concentrating. Some of the design strategies of the various companies working on the technology are described, including a pill process, MOCVD growth, and the use of diethy zinc as a dopant. Reliability testing of the diodes will be performed by NASA. Some of the alternatives to solid state amplifiers are discussed, including optical and traveling wave tube technology (TWT).

  7. 7.8GHz High power generation and extraction with a dielectric-loaded waveguide.

    SciTech Connect

    Conde, M. E.; Gai, W.; Konecny, R.; Power, J. G.; Gao, F.; Wong, T.; Yusof, Z.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs

    2009-01-01

    In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.

  8. 7.8 GHz High Power Generation And Extraction With A Dielectric-loaded Waveguide

    SciTech Connect

    Gao, F.; Conde, M. E.; Gai, W.; Konecny, R.; Liu, W.; Power, J. G.; Yusof, Z.; Jing, C.; Wong, T.

    2009-01-22

    In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.

  9. CW, high power, gyrotron development at 110 GHz for ECH applications

    SciTech Connect

    Chu, T.S.; Borchard, P.; Felch, K.; Jory, H.; Loring, C.M.

    1996-12-31

    Electron cyclotron heating (ECH) is the most promising plasma heating method to achieve fusion. High-power, long-pulse or CW gyrotrons are required in many present and future ECH experiments. For example, the planned experiment at DIII-D, the experimental tokamak at General Atomics, will require 4 MW of RF power at 110 GHz for a pulse duration of 10 seconds. The RF requirement for the planned International Thermonuclear Experimental Reactor (ITER) is 50 MW at 170 GHz and CW operation. CPI is developing high-power, CW gyrotrons at frequencies ranging from 84--170 GHz for various ECH experiments. In particular, the authors are developing a 1 MW, CW gyrotron with an internal converter at 110 GHz. To achieve the goal of 1 MW, CW operation, the authors have designed and begun fabrication of a new tube that has improved cooling to all tube parts which showed signs of overheating during the last experiment. In addition, they are looking at the possibility of using alternate output window designs to increase power handling capability. They summarize the design of the new tube and present initial test data.

  10. CW, high power, gyrotron development at 110 GHz for ECH applications

    SciTech Connect

    Chu, T.S.; Borchard, P.; Felch, K.; Jory, H.; Loring, C.M.

    1996-12-31

    Electron cyclotron heating (ECH) is the most promising plasma heating method to achieve fusion. High-power, long-pulse or CW gyrotrons are required in many present and future ECH experiments. For example, the planned experiment at DIII-D, the experimental tokamak at General Atomics, will require 4 MW of RF power at 110 GHz for a pulse duration of 10 seconds. The RF requirement for the planned International Thermonuclear Experimental Reactor (ITER) is 50 MW at 170 GHz and CW operation. CPI is developing high-power, CW gyrotrons at frequencies ranging from 84--170 GHz for various ECH experiments. In particular, the authors are developing a 1 MW, CW gyrotron with an internal converter at 110 GHz. To achieve the goal of 1 MW, CW operation, they have designed and begun fabrication of a new tube that has improved cooling to all tube parts which showed signs of overheating during the last experiment. In addition, they are looking at the possibility of using alternate output window designs to increase power handling capability. They will summarize the design of the new tube and present initial test data.

  11. Development of High Power Gyrotrons at 84, 110, and 140 GHz

    NASA Astrophysics Data System (ADS)

    Cauffman, Stephen; Blank, Monica; Borchard, Philipp; Cahalan, Pat; Chu, Sam; Felch, Kevin; Jory, Howard

    2002-11-01

    High power mm-wave sources are needed for electron cyclotron heating, current drive, and instability suppression in fusion plasmas. CPI has recently developed an 84 GHz, 500 kW, 2 second pulse gyrotron for use on K-STAR; a series of 110 GHz, 1 MW, 10 second pulse gyrotrons (two of which had achieved 1 MW 5 second pulse widths as of the writing of this abstract) for use on DIII-D; and a 140 GHz, 1 MW, CW gyrotron (for which initial tests were conducted, and which is presently being modified in preparation for further testing) for use on W-7X. Each design employs a diode magnetron injection gun, a high-order TE-mode interaction cavity, an internal mode converter to transform the excitation mode into a Gaussian output beam, and a CVD diamond output window to allow low- loss transmission of the output beam. The 84 GHz and 140 GHz systems employ a single-stage depressed voltage beam collector to enhance the overall electrical efficiency of the device and an external high voltage layout that obviates the need for oil insulation. Experimental results for each system will be discussed.

  12. Note: Efficient generation of optical sidebands at GHz with a high-power tapered amplifier

    SciTech Connect

    Zappala, J. C.; Lu, Z.-T.; Bailey, K.; O’Connor, T. P.; Jiang, W.

    2014-04-15

    Two methods using a laser-diode tapered amplifier to produce high-power, high-efficiency optical frequency sidebands over a wide tunable frequency range are studied and compared. For a total output of 500 mW at 811 nm, 20% of the power can be placed in each of the first-order sidebands. Functionality and characterization are presented within the sideband frequency region of 0.8–2.3 GHz, and it is shown that both methods can be applied beyond this frequency range. These methods provide a versatile and effective tool for atomic physics experiments.

  13. High power tests of an electroforming cavity operating at 11.424 GHz

    NASA Astrophysics Data System (ADS)

    Dolgashev, V. A.; Gatti, G.; Higashi, Y.; Leonardi, O.; Lewandowski, J. R.; Marcelli, A.; Rosenzweig, J.; Spataro, B.; Tantawi, S. G.; Yeremian, D. A.

    2016-03-01

    The achievement of ultra high accelerating gradients is mandatory in order to fabricate compact accelerators at 11.424 GHz for scientific and industrial applications. An extensive experimental and theoretical program to determine a reliable ultra high gradient operation of the future linear accelerators is under way in many laboratories. In particular, systematic studies on the 11.424 GHz frequency accelerator structures, R&D on new materials and the associated microwave technology are in progress to achieve accelerating gradients well above 120 MeV/m. Among the many, the electroforming procedure is a promising approach to manufacture high performance RF devices in order to avoid the high temperature brazing and to produce precise RF structures. We report here the characterization of a hard high gradient RF accelerating structure at 11.424 GHz fabricated using the electroforming technique. Low-level RF measurements and high power RF tests carried out at the SLAC National Accelerator Laboratory on this prototype are presented and discussed. In addition, we present also a possible layout where the water-cooling of irises based on the electroforming process has been considered for the first time.

  14. Development of a high power 12GHz PPM focused traveling wave tube

    NASA Technical Reports Server (NTRS)

    Lewis, R.

    1975-01-01

    An analytical and experimental program to demonstrate the technical feasibility of a high efficiency coupled cavity traveling wave tube with periodic permanent magnetic focusing operating at 12.06 GHz, with 1 to 2 kilowatts CW power is described. Such a tube would ultimately be used for broadcasting power transmission from a satellite. The electron gun was designed to be demountable with a replaceable cathode, and the tube to be operable in a bakeable vacuum chamber with its collector replaced by a collector. Therefore, the high efficiency design was concerned with the slow wave structure only, utilizing velocity resynchronization. A special adapter was designed which incorporated an electromagnet refocusing section and a collector baseplate to facilitate testing the collector. CW output power of 1000 watts yielding 21.5% electronic efficiency was demonstrated, with a minimum output power of 525 watts across the specified 160 MHz bandwidth.

  15. Initial results for a 170 GHz high power ITER waveguide component test stand

    NASA Astrophysics Data System (ADS)

    Bigelow, Timothy; Barker, Alan; Dukes, Carl; Killough, Stephen; Kaufman, Michael; White, John; Bell, Gary; Hanson, Greg; Rasmussen, Dave

    2014-10-01

    A high power microwave test stand is being setup at ORNL to enable prototype testing of 170 GHz cw waveguide components being developed for the ITER ECH system. The ITER ECH system will utilize 63.5 mm diameter evacuated corrugated waveguide and will have 24 >150 m long runs. A 170 GHz 1 MW class gyrotron is being developed by Communications and Power Industries and is nearing completion. A HVDC power supply, water-cooling and control system has been partially tested in preparation for arrival of the gyrotron. The power supply and water-cooling system are being designed to operate for >3600 second pulses to simulate the operating conditions planned for the ITER ECH system. The gyrotron Gaussian beam output has a single mirror for focusing into a 63.5 mm corrugated waveguide in the vertical plane. The output beam and mirror are enclosed in an evacuated duct with absorber for stray radiation. Beam alignment with the waveguide is a critical task so a combination of mirror tilt adjustments and a bellows for offsets will be provided. Analysis of thermal patterns on thin witness plates will provide gyrotron mode purity and waveguide coupling efficiency data. Pre-prototype waveguide components and two dummy loads are available for initial operational testing of the gyrotron. ORNL is managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under Contract DE-AC-05-00OR22725.

  16. Development of high power CW 3.7 GHz klystrons for fusion experiments on Tore Supra

    SciTech Connect

    Magne, R.; Armitano, A.; Berger-By, G.; Bouquey, F.; Corbel, E.; Delpech, L.; Mollard, P.; Prou, M.; Samaille, F.; Volpe, D.; Beunas, A.; Kazarian, F.

    2011-07-01

    In the frame of the CIMES project, a collaborative effort between Association Euratom-CEA and Thales Electron Devices (TED) has led to the development of a high power CW klystron TH 2103 C, working at 3.7 GHz, for plasma heating and current drive for the Tokamak Tore Supra. A prototype has been manufactured and thoroughly tested on water load in December 2007 to verify that all the parameters met the specifications. The paper will present in detail the process and results of the test of the klystrons.

  17. Demonstration of a High Power, Wideband 220 GHz Serpentine Waveguide Amplifier Fabricated by UV-LIGA

    DTIC Science & Technology

    2013-01-01

    Abstract—We present the hot test results of a 220 GHz, serpentine waveguide vacuum electron amplifier showcasing a novel embedded monofilament...band (220 GHz), and 670 GHz to date. II. AMPLIFIER DESIGN The serpentine waveguide (SWG) amplifier is designed to operate from a single, round...circuit. III. CIRCUIT FABRICATION & TESTING To create reliable, high vertical aspect ratio serpentine features as required, a UV-LIGA technique was

  18. First High power test results for 2.1 GHz superconducting photonic band gap accelerator cavities.

    PubMed

    Simakov, Evgenya I; Haynes, W Brian; Madrid, Michael A; Romero, Frank P; Tajima, Tsuyoshi; Tuzel, Walter M; Boulware, Chase H; Grimm, Terry L

    2012-10-19

    We report the results of the recent high power testing of superconducting radio frequency photonic band gap (PBG) accelerator cells. Tests of the two single-cell 2.1 GHz cavities were performed at both 4 and 2 K. An accelerating gradient of 15 MV/m and an unloaded quality factor Q(0) of 4×10(9) were achieved. It has been long realized that PBG structures have great potential in reducing long-range wakefields in accelerators. A PBG structure confines the fundamental TM(01)-like accelerating mode, but does not support higher order modes. Employing PBG cavities to filter out higher order modes in superconducting particle accelerators will allow suppression of dangerous beam instabilities caused by wakefields and thus operation at higher frequencies and significantly higher beam luminosities. This may lead towards a completely new generation of colliders for high energy physics and energy recovery linacs for the free-electron lasers.

  19. High Power SiGe X-Band (8-10 GHz) Heterojunction Bipolar Transistors and Amplifiers

    NASA Technical Reports Server (NTRS)

    Ma, Zhenqiang; Jiang, Ningyue; Ponchak, George E.; Alterovitz, Samuel A.

    2005-01-01

    Limited by increased parasitics and thermal effects as the device size becomes large, current commercial SiGe power HBTs are difficult to operate at X-band (8-12 GHz) with adequate power added efficiencies at high power levels. We found that, by changing the heterostructure and doping profile of SiGe HBTs, their power gain can be significantly improved without resorting to substantial lateral scaling. Furthermore, employing a common-base configuration with proper doping profile instead of a common-emitter configuration improves the power gain characteristics of SiGe HBTs, which thus permits these devices to be efficiently operated at X-band. In this paper, we report the results of SiGe power HBTs and MMIC power amplifiers operating at 8-10 GHz. At 10 GHz, 22.5 dBm (178 mW) RF output power with concurrent gain of 7.32 dB is measured at the peak power-added efficiency of 20.0% and the maximum RF output power of 24.0 dBm (250 mW) is achieved from a 20 emitter finger SiGe power HBT. Demonstration of single-stage X-band medium-power linear MMIC power amplifier is also realized at 8 GHz. Employing a 10-emitter finger SiGe HBT and on-chip input and output matching passive components, a linear gain of 9.7 dB, a maximum output power of 23.4 dBm and peak power added efficiency of 16% is achieved from the power amplifier. The MMIC exhibits very low distortion with third order intermodulation (IM) suppression C/I of -13 dBc at output power of 21.2 dBm and over 20dBm third order output intercept point (OIP3).

  20. Pulse repetition rate scaling from 5 to 100 GHz with a high-power semiconductor disk laser.

    PubMed

    Mangold, Mario; Zaugg, Christian A; Link, Sandro M; Golling, Matthias; Tilma, Bauke W; Keller, Ursula

    2014-03-10

    The high-power semiconductor laser studied here is a modelocked integrated external-cavity surface emitting laser (MIXSEL), which combines the gain of vertical-external-cavity surface-emitting lasers (VECSELs) with the saturable absorber of a semiconductor saturable absorber mirror (SESAM) in a single semiconductor layer stack. The MIXSEL concept allows for stable and self-starting fundamental passive modelocking in a simple straight cavity and the average power scaling is based on the semiconductor disk laser concept. Previously record-high average output power from an optically pumped MIXSEL was demonstrated, however the long pulse duration of 17 ps prevented higher pulse repetition rates and many interesting applications such as supercontinuum generation and broadband frequency comb generation. With a novel MIXSEL structure, the first femtosecond operation was then demonstrated just recently. Here we show that such a MIXSEL can also support pulse repetition rate scaling from ≈5 GHz to >100 GHz with excellent beam quality and high average output power, by mechanically changing the cavity length of the linear straight cavity and the output coupler. Up to a pulse repetition rate of 15 GHz we obtained average output power >1 W and pulse durations <4 ps. Furthermore we have been able to demonstrate the highest pulse repetition rate from any fundamentally modelocked semiconductor disk laser with 101.2 GHz at an average output power of 127 mW and a pulse duration of 570 fs.

  1. High-power pulsed gyrotron for 300 GHz-band collective Thomson scattering diagnostics in the Large Helical Device

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Yuusuke; Saito, Teruo; Tatematsu, Yoshinori; Ikeuchi, Shinji; Manuilov, Vladimir N.; Kasa, Jun; Kotera, Masaki; Idehara, Toshitaka; Kubo, Shin; Shimozuma, Takashi; Tanaka, Kenji; Nishiura, Masaki

    2015-01-01

    A high-power pulse gyrotron was developed to generate a probe wave for 300 GHz-band collective Thomson scattering (CTS) diagnostics in the Large Helical Device. In this frequency range, avoiding mode competition is critical to realizing high-power and stable oscillation with a narrow frequency bandwidth. A moderately over-moded cavity was investigated to ensure sufficient isolation of a desired mode from neighbouring modes, and to achieve high power output simultaneously. A cavity with the TE14,2 operation mode, a triode electron gun with an intense laminar electron beam, and an internal mode convertor were designed to construct a prototype tube. It was experimentally observed that oscillation of the TE14,2 mode was strong enough for mode competition, and provided high power with sufficient stability. The oscillation characteristics associated with the electron beam properties were compared with the numerical characteristics to find an optimum operating condition. As a result, single-mode operation with maximum output power of 246 kW was demonstrated at 294 GHz with 65 kV/14 A electron beam, yielding efficiency of ˜27%. The radiation pattern was confirmed to be highly Gaussian. The duration of the 130 kW pulse, which is presently limited by the power supply, was extended up to 30 µs. The experimental results validate our design concept and indicate the potential for realizing a gyrotron with higher power and longer pulse toward practical use in 300 GHz CTS diagnostics.

  2. Investigation on transmission and reflection characteristics of plasma array to 6 GHz high-power microwave

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Yang, Zhongcun; Wan, Jianing; Liu, Hao

    2016-10-01

    For the safety of electronic equipment, a double-layer barrier of cylindrical plasma array was designed, and its protective performance to high-power microwave (HPM) were analyzed and the protective performance experiment was conducted. Combining the density distribution characteristic of the discharge plasma, the shielding effectiveness of the double-layer plasma on 6GHz HPM pulse was studied. The experiment results indicate that the protective effectiveness of two layers plasma array is better than that of one layer. Two layers plasma array can make the peak electric field of transmission waveform less than interference threshold of electronic equipment to achieve better protection effectiveness. Transmission attenuation of one layer and two layers plasma array to HPM can reach -6.6066dB and -24.9357dB. The results also show that for the existence of multiple reflection, even the plasma electron density is not high enough, it can realize a strong attenuation. The experiment results in this paper are of great significance in protecting against HPM and electromagnetic pulse.

  3. GHz high power Yb-doped picosecond fiber laser and supercontinuum generation.

    PubMed

    Gao, Jing; Ge, Tingwu; Li, Wuyi; Kuang, Hongshen; Wang, Zhiyong

    2014-12-20

    We demonstrated a 97 W all-fiber picosecond master oscillator power amplifier seeding by an actively harmonic mode-locked Yb-doped fiber laser. The laser seed pulse duration was 7.7 ps at a 1.223 GHz repetition rate with a central wavelength of 1062 nm. In addition, by launching the amplified pulses into a 5 m long photonic crystal fiber, we obtained a 41.8 W supercontinuum covering the wavelength from 600 to 1700 nm with a 10 dB bandwidth of 1040 nm.

  4. The 60 GHz solid state power amplifier

    NASA Technical Reports Server (NTRS)

    Mcclymonds, J.

    1991-01-01

    A new amplifier architecture was developed during this contract that is superior to any other solid state approach. The amplifier produced 6 watts with 4 percent efficiency over a 2 GHz band at 61.5 GHz. The unit was 7 x 9 x 3 inches in size, 5.5 pounds in weight, and the conduction cooling through the baseplate is suitable for use in space. The amplifier used high efficiency GaAs IMPATT diodes which were mounted in 1-diode circuits, called modules. Eighteen modules were used in the design, and power combining was accomplished with a proprietary passive component called a combiner plate.

  5. High-Power Plasma Switch for 11.4 GHz Microwave Pulse Compressor

    SciTech Connect

    Jay L. Hirshfield

    2010-03-04

    Results obtained in several experiments on active RF pulse compression at X-band using a magnicon as the high-power RF source are presented. In these experiments, microwave energy was stored in high-Q TE01 and TE02 modes of two parallel-fed resonators, and then discharged using switches activated with rapidly fired plasma discharge tubes. Designs and high-power tests of several versions of the compressor are described. In these experiments, coherent pulse superposition was demonstrated at a 5–9 MW level of incident power. The compressed pulses observed had powers of 50–70 MW and durations of 40–70 ns. Peak power gains were measured to be in the range of 7:1–11:1 with efficiency in the range of 50–63%.

  6. A 1.8-3 GHz-band high efficiency GaAs pHEMT power amplifier MMIC

    NASA Astrophysics Data System (ADS)

    Qin, Ge; Hongqi, Tao; Xuming, Yu

    2015-12-01

    This paper describes an S-band wideband high efficiency power amplifier based on the Nanjing Electron Device Institute's GaAs pHEMT monolithic microwave integrated circuit (MMIC) technology. To realize high efficiency, the two stage power amplifier is designed with a driver ratio of 1 : 8. The low-pass filter/high-pass filter combined matching circuit is applied to the amplifier to reduce the chip size, as well as to realize the optimum impedances over a wide bandwidth for high efficiency at each stage. Biased at class AB under a drain supply voltage of 5 V, the amplifier delivers 33-34 dBm saturated output power across the frequency range of 1.8 to 3 GHz with associated power-added efficiency of 35%-45% and very flat power gain of 25-26 dB in CW mode. The size of this MMIC is very compact with 2.7 × 2.75 mm2.

  7. High (1 GHz) repetition rate compact femtosecond laser: A powerful multiphoton tool for nanomedicine and nanobiotechnology

    NASA Astrophysics Data System (ADS)

    Ehlers, A.; Riemann, I.; Martin, S.; Le Harzic, R.; Bartels, A.; Janke, C.; König, K.

    2007-07-01

    Multiphoton tomography of human skin and nanosurgery of human chromosomes have been performed with a 1GHz repetition rate laser by the use of the commercially available femtosecond multiphoton laser tomograph DermaInspect as well as a compact galvoscanning microscope. We performed the autofluorescence tomography up to 100μm in the depth of human skin. Submicron cutting lines and hole drillings have been conducted on labeled human chromosomes.

  8. Study of a high power sine waveguide traveling wave tube amplifier centered at 8 GHz

    NASA Astrophysics Data System (ADS)

    Hoff, Brad W.; Simon, David S.; French, David M.; Lau, Y. Y.; Wong, Patrick

    2016-10-01

    Performance of a 20-stage X-band sine waveguide amplifier, driven by a 40 A, 100 kV, cylindrical electron beam, is studied using numerical simulation and interpreted using Pierce's classical traveling wave tube theory. For an input signal power level of 1.8 kW, particle-in-cell simulations predict gain and bandwidth values exceeding 14 dB and 13%, respectively. For an input signal power level of 7.2 kW, particle-in-cell simulations predict gain and bandwidth values exceeding 12 dB and 15%, respectively, with output power levels exceeding 110 kW at peak gain. Also given are: an assessment of the space charge factor (Pierce's QC parameter) for the complex circuit using simulation data, and an evaluation of the harmonic contents in the beam current.

  9. Power-Amplifier Module for 145 to 165 GHz

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene; Peralta, Alejandro

    2007-01-01

    A power-amplifier module that operates in the frequency range of 145 to 165 GHz has been designed and constructed as a combination of (1) a previously developed monolithic microwave integrated circuit (MMIC) power amplifier and (2) a waveguide module. The amplifier chip was needed for driving a high-electron-mobility-transistor (HEMT) frequency doubler. While it was feasible to connect the amplifier and frequency-doubler chips by use of wire bonds, it was found to be much more convenient to test the amplifier and doubler chips separately. To facilitate separate testing, it was decided to package the amplifier and doubler chips in separate waveguide modules. Figure 1 shows the resulting amplifier module. The amplifier chip was described in "MMIC HEMT Power Amplifier for 140 to 170 GHz" (NPO-30127), NASA Tech Briefs, Vol. 27, No. 11, (November 2003), page 49. To recapitulate: This is a three-stage MMIC power amplifier that utilizes HEMTs as gain elements. The amplifier was originally designed to operate in the frequency range of 140 to 170 GHz. The waveguide module is based on a previously developed lower frequency module, redesigned to support operation in the frequency range of 140 to 220 GHz. Figure 2 presents results of one of several tests of the amplifier module - measurements of output power and gain as functions of input power at an output frequency of 150 GHz. Such an amplifier module has many applications to test equipment for power sources above 100 GHz.

  10. MMIC HEMT Power Amplifier for 140 to 170 GHz

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene; Radisic, Vesna; Ngo, Catherine; Janke, Paul; Hu, Ming; Micovic, Miro

    2003-01-01

    A three-stage monolithic microwave integrated circuit (MMIC) power amplifier that features high-electron-mobility transistors (HEMTs) as gain elements is reviewed. This amplifier is designed to operate in the frequency range of 140 to 170 GHz, which contains spectral lines of several atmospheric molecular species plus subharmonics of other such spectral lines. Hence, this amplifier could serve as a prototype of amplifiers to be incorporated into heterodyne radiometers used in atmospheric science. The original intended purpose served by this amplifier is to boost the signal generated by a previously developed 164-GHz MMIC HEMT doubler and drive a 164-to-328-GHz doubler to provide a few milliwatts of power at 328 GHz.

  11. Development of 26 GHz Dielectric-Based Wakefield Power Extractor

    SciTech Connect

    Jing, C.; Kanareykin, A.; Schoessow, P.; Gai, W.; Konecny, R.; Power, J. G.; Conde, M.; Gao, F.; Kazakov, S.; Kustov, A.

    2009-01-22

    High frequency, high power rf sources are needed for many applications in particle accelerators, communications, radar, etc. In this article we present a design of a 26 GHz high power rf source based on the extraction of wakefields from a relativistic electron beam. The extractor is designed to couple out rf power generated from a high charge electron bunch train traversing a dielectric loaded waveguide. Using a 20 nC bunch train (bunch length of 1.5 mm) at the Argonne Wakefield Accelerator (AWA) facility, we can obtain a steady 26 GHz output power of 148 MW. The extractor has been fabricated and bench tested, with the first high power beam experiments to be performed in the coming year.

  12. Development of 26GHz dielectric-based wakefield power extractor.

    SciTech Connect

    Jing, C.; Gai, W.; Konecny, R.; Power, J. G.; Conde, M.; Gao, F.; Kazakov, S.; Kustov, A.; High Energy Physics; Euclid Techlabs; KEK; Dynamics Software

    2009-01-01

    High frequency, high power rf sources are needed for many applications in particle accelerators, communications, radar, etc. In this article we present a design of a 26 GHz high power rf source based on the extraction of wakefields from a relativistic electron beam. The extractor is designed to couple out rf power generated from a high charge electron bunch train traversing a dielectric loaded waveguide. Using a 20 nC bunch train (bunch length of 1.5 mm) at the Argonne Wakefield Accelerator (AWA) facility, we can obtain a steady 26 GHz output power of 148 MW. The extractor has been fabricated and bench tested, with the first high power beam experiments to be performed in the coming year.

  13. Components for transmission of very high power mm waves (200 kW at 28, 70 and 140 GHz) in overmoded circular waveguides

    NASA Astrophysics Data System (ADS)

    Thumm, M.; Erckmann, V.; Kasparek, W.; Kumric, H.; Mueller, G. A.; Schueller, P. G.; Wilhelm, R.

    1986-03-01

    Optimized overmoded circular waveguide components of transmission lines developed for high-power (200 kW) millimeter wave applications at 28, 70, and 140 GHz, as e.g., electron cyclotron resonance heating of plasmas for thermonuclear fusion research with gyrotrons, are described. Axisymmetric, narrow, pencil-like beams with well-defined polarization (HE11 hybrid mode) are used at open-ended corrugated waveguide antennas. The HE11 mode is generated from TE0n gyrotron modes by multistep mode conversion: TE0n yields T001 yields TE11 yields HE11 or TE0n yields TE01 yields TM11 yields HE11. Analyses and measurements on mode transducer systems of the first type at 28 and 70 GHz and of the second type at 140 GHz are reported. In all cases the overall efficiency of the complete mode conversion sequence in the desired mode is 92% to 95%. Mode purity in the transmission lines is conserved by using corrugated gradual waveguide bends with optimized curvature distribution and diameter tapers with nonlinear contours. Highly efficient corrugated-wall mode selective filters decouple the different waveguide sections. Mode content and reflected powere are determined by a k-spectrometer. Absolute power calibration is done with calorimetric loads using an organic absorbing fluid.

  14. Tunable GHz pulse repetition rate operation in high-power TEM(00)-mode Nd:YLF lasers at 1047 nm and 1053 nm with self mode locking.

    PubMed

    Huang, Y J; Tzeng, Y S; Tang, C Y; Huang, Y P; Chen, Y F

    2012-07-30

    We report on a high-power diode-pumped self-mode-locked Nd:YLF laser with the pulse repetition rate up to several GHz. A novel tactic is developed to efficiently select the output polarization state for achieving the stable TEM(00)-mode self-mode-locked operations at 1053 nm and 1047 nm, respectively. At an incident pump power of 6.93 W and a pulse repetition rate of 2.717 GHz, output powers as high as 2.15 W and 1.35 W are generated for the σ- and π-polarization, respectively. We experimentally find that decreasing the separation between the gain medium and the input mirror not only brings in the pulse shortening thanks to the enhanced effect of the spatial hole burning, but also effectively introduces the effect of the spectral filtering to lead the Nd:YLF laser to be in a second harmonic mode-locked status. Consequently, pulse durations as short as 8 ps and 8.5 ps are obtained at 1053 nm and 1047 nm with a pulse repetition rate of 5.434 GHz.

  15. High power system for ECRH at 140Ghz, 2MW, 0.5s on FTU tokamak

    SciTech Connect

    Sozzi, C.; Bozzi, R.; Bruschi, A.; Cirant, S.; Gandini, F.; Granucci, G.; Mellera, V.; Muzzini, V.; Nardone, A.; Simonetto, A.; Spinicchia, N.; Berardi, B.; Ciccone, G.; DiGiovenale, S.; Iannone, F.; Lupini, S.; Mantovani, S.; Pesci, E.

    1999-09-20

    The 140GHz, 2MW, 0.5s ECRH system on FTU tokamak integrates closed waveguide transmission lines ({approx_equal}30 m) with quasi optical systems at both ends for efficient coupling from the 4 gyrotrons to the 4 waveguides and from these to the plasma through a single access port. Poloidal and toroidal control of the beam's launching angles and polarization is performed without movable components close to the plasma. Most of the components of each generation and transmission system were designed to operate at a power level higher than 0.5 MW, and a possible up-grade to a full 1 MW, 0.5 s capability is discussed.

  16. Design of a high-power, high-gain, 2nd harmonic, 22.848 GHz gyroklystron

    NASA Astrophysics Data System (ADS)

    Veale, M.; Purohit, P.; Lawson, W.

    2013-08-01

    In this paper we consider the design of a four-cavity, high-gain K-band gyroklystron experiment for high gradient structure testing. The frequency doubling gyroklystron utilizes a beam voltage of 500 kV and a beam current of 200 A from a magnetron injection gun (MIG) originally designed for a lower-frequency device. The microwave circuit features input and gain cavities in the circular TE011 mode and penultimate and output cavities that operate at the second harmonic in the TE021 mode. We investigate the MIG performance and study the behavior of the circuit for different values of perpendicular to parallel velocity ratio (α = V⊥ / Vz). This microwave tube is expected to be able to produce at least 20 MW of power in 1μs pulses at a repetition rate of at least 120 Hz. A maximum efficiency of 26% and a large signal gain of 58 dB under zero-drive stable conditions were simulated for a velocity ratio equal to 1.35.

  17. Design of a high-power, high-gain, 2nd harmonic, 22.848 GHz gyroklystron

    SciTech Connect

    Veale, M.; Purohit, P.; Lawson, W.

    2013-08-15

    In this paper we consider the design of a four-cavity, high-gain K-band gyroklystron experiment for high gradient structure testing. The frequency doubling gyroklystron utilizes a beam voltage of 500 kV and a beam current of 200 A from a magnetron injection gun (MIG) originally designed for a lower-frequency device. The microwave circuit features input and gain cavities in the circular TE{sub 011} mode and penultimate and output cavities that operate at the second harmonic in the TE{sub 021} mode. We investigate the MIG performance and study the behavior of the circuit for different values of perpendicular to parallel velocity ratio (α= V{sub ⊥}/ V{sub z}). This microwave tube is expected to be able to produce at least 20 MW of power in 1μs pulses at a repetition rate of at least 120 Hz. A maximum efficiency of 26% and a large signal gain of 58 dB under zero-drive stable conditions were simulated for a velocity ratio equal to 1.35.

  18. High efficiency IMPATT diodes for 60 GHz intersatellite link applications

    NASA Technical Reports Server (NTRS)

    Haugland, E. J.

    1984-01-01

    Intersatellite links are expected to play an increasingly important role in future satellite systems. Improved components are required to properly utilize the wide bandwidth allocated for intersatellite link applications around 60 GHz. IMPATT diodes offer the highest potential performance as solid state power sources for a 60 GHz transmitter. Presently available devices do not have the desired power and efficiency. High efficiency, high power IMPATT diodes for intersatellite link applications are being developed by NASA and other government agencies. This paper describes the development of high efficiency 60 GHz IMPATT diodes by NASA. These programs are cofunded by the U.S. Air Force, Space Division.

  19. High efficiency IMPATT diodes for 60 GHz intersatellite link applications

    NASA Technical Reports Server (NTRS)

    Haugland, E. J.

    1984-01-01

    Intersatellite links are expected to play an increasingly important role in future satellite systems. Improved components are required to properly utilize the wide bandwidth allocated for intersatellite link applications around 60 GHz. IMPATT diodes offer the highest potential performance as solid state power sources for a 60 GHz transmitter. Presently available devices do not have the desired power and efficiency. High efficiency, high power IMPATT diodes for intersatellite link applications are being developed by NASA and other government agencies. The development of high efficiency 60 GHz IMPATT diodes by NASA is described.

  20. Bit-error-rate testing of high-power 30-GHz traveling-wave tubes for ground-terminal applications

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Kurt A.

    1987-01-01

    Tests were conducted at NASA Lewis to measure the bit-error-rate performance of two 30-GHz 200-W coupled-cavity traveling-wave tubes (TWTs). The transmission effects of each TWT on a band-limited 220-Mbit/s SMSK signal were investigated. The tests relied on the use of a recently developed digital simulation and evaluation system constructed at Lewis as part of the 30/20-GHz technology development program. This paper describes the approach taken to test the 30-GHz tubes and discusses the test data. A description of the bit-error-rate measurement system and the adaptations needed to facilitate TWT testing are also presented.

  1. Bit-error-rate testing of high-power 30-GHz traveling wave tubes for ground-terminal applications

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Kurt A.; Fujikawa, Gene

    1986-01-01

    Tests were conducted at NASA Lewis to measure the bit-error-rate performance of two 30 GHz, 200 W, coupled-cavity traveling wave tubes (TWTs). The transmission effects of each TWT were investigated on a band-limited, 220 Mb/sec SMSK signal. The tests relied on the use of a recently developed digital simulation and evaluation system constructed at Lewis as part of the 30/20 GHz technology development program. The approach taken to test the 30 GHz tubes is described and the resultant test data are discussed. A description of the bit-error-rate measurement system and the adaptations needed to facilitate TWT testing are also presented.

  2. Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission

    NASA Technical Reports Server (NTRS)

    Sullivan, Gerry

    2001-01-01

    For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

  3. High Power 7-GHz Bandwidth External-Cavity Diode Laser Array and Its Use in Optically Pumping Singlet Delta Oxygen

    DTIC Science & Technology

    2006-10-11

    array,” Opt. Lett. 19, 1741 (1994). 2. Stuart MacCormack, Jack Feinberg, and M. H. Garrett , “Injection locking a laser-diode array with a phase...generate O2( 1∆) molecules, frequently called Singlet Delta Oxygen (SDO) molecules. High-power chemical oxygen-iodine lasers ( COIL ) use energy...45 A, thermal roll -over effect starts and output power drops due to high temperature (~30oC) of the DLA. The green data are the DLA’s free-running

  4. Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D

    SciTech Connect

    Jay L. Hirshfield

    2012-07-26

    Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

  5. A low-power, high-throughput maximum-likelihood convolutional decoder chip for NASA's 30/20 GHz program

    NASA Technical Reports Server (NTRS)

    Mccallister, R. D.; Crawford, J. J.

    1981-01-01

    It is pointed out that the NASA 30/20 GHz program will place in geosynchronous orbit a technically advanced communication satellite which can process time-division multiple access (TDMA) information bursts with a data throughput in excess of 4 GBPS. To guarantee acceptable data quality during periods of signal attenuation it will be necessary to provide a significant forward error correction (FEC) capability. Convolutional decoding (utilizing the maximum-likelihood techniques) was identified as the most attractive FEC strategy. Design trade-offs regarding a maximum-likelihood convolutional decoder (MCD) in a single-chip CMOS implementation are discussed.

  6. HIGH POWER TEST OF A 3.9 GHZ 5-CELL DEFLECTING-MODE CAVITY IN A CRYOGENIC OPERATION

    SciTech Connect

    Shin, Young-Min; Church, Michael

    2013-11-24

    A 3.9 GHz deflecting mode (S, TM110) cavity has been long used for six-dimensional phase-space beam manipulation tests [1-5] at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently planned at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretical prediction. We have been performing full analysis of the designed cavity by analytic calculation and comprehensive system simulation analysis to solve complex thermodynamics and mechanical stresses. The re-assembled cryomodule is currently under the test with a 50 kW klystron at the Fermilab A0 beamline, which will benchmark the modeling analysis. The test result will be used to design vacuum cryomodules for the 3.9 GHz deflecting mode cavity that will be employed at the ASTA facility for beam diagnostics and phase-space control.

  7. A 670 GHz gyrotron with record power and efficiency

    NASA Astrophysics Data System (ADS)

    Glyavin, M. Yu.; Luchinin, A. G.; Nusinovich, G. S.; Rodgers, J.; Kashyn, D. G.; Romero-Talamas, C. A.; Pu, R.

    2012-10-01

    A 670 GHz gyrotron with record power and efficiency has been developed in joint experiments of the Institute of Applied Physics, Russian Academy of Sciences (Nizhny Novgord, Russia), and the University of Maryland (USA) teams. The magnetic field of 27-28 T required for operation at the 670 GHz at the fundamental cyclotron resonance is produced by a pulsed solenoid. The pulse duration of the magnetic field is several milliseconds. A gyrotron is driven by a 70 kV, 15 A electron beam, so the beam power is on the order of 1 MW in 10-20 ms pulses. The ratio of the orbital to axial electron velocity components is in the range of 1.2-1.3. The gyrotron is designed to operate in the TE31,8-mode. Operation in a so high-order mode results in relatively low ohmic losses (less than 10% of the radiated power). Achieved power of the outgoing radiation (210 kW) and corresponding efficiency (about 20%) represent record numbers for high-power sources of sub-THz radiation.

  8. Characterization of Power MESFETs at 21 GHz.

    DTIC Science & Technology

    1981-09-15

    constructed for use between 12 and 24 GHz based on a microwave- diplexer filter. The bias-tee is constructed using air and teflon- loaded coaxial transmission...FREQUENCY 21 GHz GAIN (dB) VDe 6.5 V 8 I = 139 mnA AT RF MAX 7 28- D 6 z171 mnA no RF 5 4 -186 mnA AT 22.9 24 -dBmn OUTImI 2020 ~16- 14 12 12 88 4 4

  9. InP MMIC Chip Set for Power Sources Covering 80-170 GHz

    NASA Technical Reports Server (NTRS)

    Ngo, Catherine

    2001-01-01

    We will present a Monolithic Millimeter-wave Integrated Circuit (MMIC) chip set which provides high output-power sources for driving diode frequency multipliers into the terahertz range. The chip set was fabricated at HRL Laboratories using a 0.1-micrometer gate-length InAlAs/InGaAs/InP high electron mobility transistor (HEMT) process, and features transistors with an f(sub max) above 600 GHz. The HRL InP HEMT process has already demonstrated amplifiers in the 60-200 GHz range. In this paper, these high frequency HEMTs form the basis for power sources up to 170 GHz. A number of state-of-the-art InP HEMT MMICs will be presented. These include voltage-controlled and fixed-tuned oscillators, power amplifiers, and an active doubler. We will first discuss an 80 GHz voltage-controlled oscillator with 5 GHz of tunability and at least 17 mW of output power, as well as a 120 GHz oscillator providing 7 mW of output power. In addition, we will present results of a power amplifier which covers the full WRIO waveguide band (75-110 GHz), and provides 40-50 mW of output power. Furthermore, we will present an active doubler at 164 GHz providing 8% bandwidth, 3 mW of output power, and an unprecedented 2 dB of conversion loss for an InP HEMT MMIC at this frequency. Finally, we will demonstrate a power amplifier to cover 140-170 GHz with 15-25 mW of output power and 8 dB gain. These components can form a power source in the 155-165 GHz range by cascading the 80 GHz oscillator, W-band power amplifier, 164 GHz active doubler and final 140-170 GHz power amplifier for a stable, compact local oscillator subsystem, which could be used for atmospheric science or astrophysics radiometers.

  10. 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.

  11. 17 GHz High Gradient Accelerator Research

    SciTech Connect

    Temkin, Richard J.; Shapiro, Michael A.

    2013-07-10

    This is a report on the MIT High Gradient Accelerator Research program which has included: Operation of the 17 GHz, 25 MeV MIT/Haimson Research Corp. electron accelerator at MIT, the highest frequency, stand-alone accelerator in the world; collaboration with members of the US High Gradient Collaboration, including the design and test of novel structures at SLAC at 11.4 GHz; the design, construction and testing of photonic bandgap structures, including metallic and dielectric structures; the investigation of the wakefields in novel structures; and the training of the next generation of graduate students and postdoctoral associates in accelerator physics.

  12. IMPATT power building blocks for 20 GHz spaceborne transmit amplifier

    NASA Technical Reports Server (NTRS)

    Asmus, J.; Cho, Y.; Degruyl, J.; Ng, E.; Giannakopoulos, A.; Okean, H. C.

    1982-01-01

    Single-stage circulator coupled IMPATT building block constituents of a 20-GHz solid state power amplifier (SSPA) currently under development for spaceborne downlink transmitter usage have been demonstrated as providing 1.5 to 2.0W RF power output at 4 to 5 dB operating gain over a 1 GHz bandwidth. Using either commercially available or recently developed in-house GaAs Schottky Read-profile IMPATT diodes, DC/RF power added efficiencies of 14 to 15% were achieved in these amplifier stages. A two stage IMPATT driver amplifier with similar RF output power capability exhibited 13 + or - 0.5 dB operating gain over a 1 GHz bandwidth.

  13. Submicron gate InP power MISFET's with improved output power density at 18 and 20 GHz

    NASA Technical Reports Server (NTRS)

    Biedenbender, M. D.; Kapoor, Vik J.; Shalkhauser, K. A.; Messick, L. J.; Nguyen, R.; Schmitz, D.; Juergensen, H.

    1991-01-01

    The microwave characteristics are presented at 18 and 20 GHz of submicron gate indium phosphide (InP) metal-insulator-semiconductor field-effect transistors (MISFET's) for high output power density applications. InP power MISFET's were fabricated and the output power density was investigated as a function of drain-source spacing. The best output power density and gain were obtained for drain-source spacing of 3 microns. The output power density is 2.7 times greater than was previously measured for InP MISFET's at 18 and 20 GHz, and the power-added efficiency also increased.

  14. Submicron gate InP power MISFET's with improved output power density at 18 and 20 GHz

    NASA Technical Reports Server (NTRS)

    Biedenbender, Michael D.; Kapoor, Vik J.; Shalkhauser, Kurt A.; Messick, Louis J.; Nguyen, Richard; Schmitz, Dietmar; Jurgensen, Holger

    1991-01-01

    The microwave characteristics are presented at 18 and 20 GHz of submicron gate indium phosphide (InP) metal-insulator-semiconductor field-effect transistors (MISFETs) for high output power density applications. InP power MISFET's were fabricated and the output power density was investigated as a function of drain-source spacing. The best output power density and gain were obtained for drain-source spacing of 3 micron. The output power density is 2.7 times greater than was previously measured for InP MISFET's at 18 and 20 GHz, and the power-added efficiency also increased.

  15. The 20 GHz power GaAs FET development

    NASA Technical Reports Server (NTRS)

    Crandell, M.

    1986-01-01

    The development of power Field Effect Transistors (FET) operating in the 20 GHz frequency band is described. The major efforts include GaAs FET device development (both 1 W and 2 W devices), and the development of an amplifier module using these devices.

  16. Impact of High Power Interference Sources in Planning and Deployment of Wireless Sensor Networks and Devices in the 2.4 GHz Frequency Band in Heterogeneous Environments

    PubMed Central

    Iturri, Peio López; Nazábal, Juan Antonio; Azpilicueta, Leire; Rodriguez, Pablo; Beruete, Miguel; Fernández-Valdivielso, Carlos; Falcone, Francisco

    2012-01-01

    In this work, the impact of radiofrequency radiation leakage from microwave ovens and its effect on 802.15.4 ZigBee-compliant wireless sensor networks operating in the 2.4 GHz Industrial Scientific Medical (ISM) band is analyzed. By means of a novel radioplanning approach, based on electromagnetic field simulation of a microwave oven and determination of equivalent radiation sources applied to an in-house developed 3D ray launching algorithm, estimation of the microwave oven's power leakage is obtained for the complete volume of an indoor scenario. The magnitude and the variable nature of the interference is analyzed and the impact in the radio link quality in operating wireless sensors is estimated and compared with radio channel measurements as well as packet measurements. The measurement results reveal the importance of selecting an adequate 802.15.4 channel, as well as the Wireless Sensor Network deployment strategy within this type of environment, in order to optimize energy consumption and increase the overall network performance. The proposed method enables one to estimate potential interference effects in devices operating within the 2.4 GHz band in the complete scenario, prior to wireless sensor network deployment, which can aid in achieving the most optimal network topology. PMID:23202228

  17. Impact of high power interference sources in planning and deployment of wireless sensor networks and devices in the 2.4 GHz frequency band in heterogeneous environments.

    PubMed

    Iturri, Peio López; Nazábal, Juan Antonio; Azpilicueta, Leire; Rodriguez, Pablo; Beruete, Miguel; Fernández-Valdivielso, Carlos; Falcone, Francisco

    2012-11-12

    In this work, the impact of radiofrequency radiation leakage from microwave ovens and its effect on 802.15.4 ZigBee-compliant wireless sensor networks operating in the 2.4 GHz Industrial Scientific Medical (ISM) band is analyzed. By means of a novel radioplanning approach, based on electromagnetic field simulation of a microwave oven and determination of equivalent radiation sources applied to an in-house developed 3D ray launching algorithm, estimation of the microwave oven’s power leakage is obtained for the complete volume of an indoor scenario. The magnitude and the variable nature of the interference is analyzed and the impact in the radio link quality in operating wireless sensors is estimated and compared with radio channel measurements as well as packet measurements. The measurement results reveal the importance of selecting an adequate 802.15.4 channel, as well as the Wireless Sensor Network deployment strategy within this type of environment, in order to optimize energy consumption and increase the overall network performance. The proposed method enables one to estimate potential interference effects in devices operating within the 2.4 GHz band in the complete scenario, prior to wireless sensor network deployment, which can aid in achieving the most optimal network topology.

  18. Development of a High-Power Wideband Amplifier on the Basis of a Free-Electron Maser Having an Operating Frequency Near 30 GHz: Modeling and Results of the Initial Experiments

    NASA Astrophysics Data System (ADS)

    Bandurkin, I. V.; Donets, D. E.; Kaminsky, A. K.; Kuzikov, S. V.; Perel'shteyn, E. A.; Peskov, N. Yu.; Savilov, A. V.; Sedykh, S. N.

    2017-01-01

    We develop a high-power wideband amplifier based on a free-electron maser for particle acceleration, which will be operated in the 30 GHz frequency band, on the basis of the LIU-3000 linear induction accelerator forming an electron beam with an electron energy of 0.8 MeV, a current of 250 A, and a pulse duration of 200 ns. As the operating regime, we chose the regime of grazing of dispersion curves, since, according to the modeling performed, it allows one to ensure an instantaneous amplification band of about 5-7% in an undulator with regular winding for an output radiation power at a level of 20 MW and a gain of 30-35 dB. The results of the first experiments studying this FEM-based scheme are presented, in which the specified power level is achieved in the range around 30 GHz, and fast tuning of ±0.5 GHz in the band of variations in the frequency of the master magnetron is demonstrated. Modeling shows that the use of the non-resonance trapping/braking regime, which is realized in an undulator with profiled parameters, allows one to expect an increase in the radiation power of up to 35-40 MW with simultaneous widening of the amplification band up to 30% under the conditions of the LIU-3000 experiments.

  19. Applied research using a 30 GHz free-electron maser: Experimental study of interacton of high-power pulsed radiation with metals

    NASA Astrophysics Data System (ADS)

    Baev, V. G.; Vdovin, V. A.; Vikharev, A. A.; Ginzburg, N. S.; Golubev, I. I.; Golubykh, S. M.; Zaitsev, N. I.; Kaminsky, A. K.; Kovalev, Yu. A.; Kozlov, A. P.; Kratko, A. F.; Kryachko, I. A.; Kuzikov, S. V.; Lesnikovich, A. I.; Milevich, I. A.; Perel'shtein, E. A.; Peskov, N. Yu.; Petelin, M. I.; Sedykh, S. N.; Tyutyunnikov, S. I.; Fedotova, Yu. A.

    2012-01-01

    We describe a facility for testing the properties of different objects affected by a sequence of highpower pulses of the microwave electromagnetic field. The facility performance is implemented due to the power level and stability of the single-mode generation of a free electron maser with an output frequency of 30 GHz, which have been achieved at the Joint Institute for Nuclear Research and the Institute of Applied Physics of the Russian Academy of Sciences. This paper describes the experiments on studying of the thermal fatigue of the copper surface in a test cavity, which models the thermal regime of the accelerating structure of the CLIC project (CERN), as well as the experiments on irradiation of biological tissues, metal films, and nanoclusters.

  20. A 12 GHz RF Power Source for the CLIC Study

    SciTech Connect

    Schirm, Karl; Curt, Stephane; Dobert, Steffen; McMonagle, Gerard; Rossat, Ghislain; Syratchev, Igor; Timeo, Luca; Haase, Andrew Jensen, Aaron; Jongewaard, Erik; Nantista, Christopher; Sprehn, Daryl; Vlieks, Arnold; Hamdi, Abdallah; Peauger, Franck; Kuzikov, Sergey; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  1. Miniature MMIC Low Mass/Power Radiometer Modules for the 180 GHz GeoSTAR Array

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka; Tanner, Alan; Pukala, David; Lambrigtsen, Bjorn; Lim, Boon; Mei, Xiaobing; Lai, Richard

    2010-01-01

    We have developed and demonstrated miniature 180 GHz Monolithic Microwave Integrated Circuit (MMIC) radiometer modules that have low noise temperature, low mass and low power consumption. These modules will enable the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) of the Precipitation and All-weather Temperature and Humidity (PATH) Mission for atmospheric temperature and humidity profiling. The GeoSTAR instrument has an array of hundreds of receivers. Technology that was developed included Indium Phosphide (InP) MMIC Low Noise Amplifiers (LNAs) and second harmonic MMIC mixers and I-Q mixers, surface mount Multi-Chip Module (MCM) packages at 180 GHz, and interferometric array at 180 GHz. A complete MMIC chip set for the 180 GHz receiver modules (LNAs and I-Q Second harmonic mixer) was developed. The MMIC LNAs had more than 50% lower noise temperature (NT=300K) than previous state-of-art and MMIC I-Q mixers demonstrated low LO power (3 dBm). Two lots of MMIC wafers were processed with very high DC transconductance of up to 2800 mS/mm for the 35 nm gate length devices. Based on these MMICs a 180 GHz Multichip Module was developed that had a factor of 100 lower mass/volume (16x18x4.5 mm3, 3g) than previous generation 180 GHz receivers.

  2. Miniature MMIC Low Mass/Power Radiometer Modules for the 180 GHz GeoSTAR Array

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka; Tanner, Alan; Pukala, David; Lambrigtsen, Bjorn; Lim, Boon; Mei, Xiaobing; Lai, Richard

    2010-01-01

    We have developed and demonstrated miniature 180 GHz Monolithic Microwave Integrated Circuit (MMIC) radiometer modules that have low noise temperature, low mass and low power consumption. These modules will enable the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) of the Precipitation and All-weather Temperature and Humidity (PATH) Mission for atmospheric temperature and humidity profiling. The GeoSTAR instrument has an array of hundreds of receivers. Technology that was developed included Indium Phosphide (InP) MMIC Low Noise Amplifiers (LNAs) and second harmonic MMIC mixers and I-Q mixers, surface mount Multi-Chip Module (MCM) packages at 180 GHz, and interferometric array at 180 GHz. A complete MMIC chip set for the 180 GHz receiver modules (LNAs and I-Q Second harmonic mixer) was developed. The MMIC LNAs had more than 50% lower noise temperature (NT=300K) than previous state-of-art and MMIC I-Q mixers demonstrated low LO power (3 dBm). Two lots of MMIC wafers were processed with very high DC transconductance of up to 2800 mS/mm for the 35 nm gate length devices. Based on these MMICs a 180 GHz Multichip Module was developed that had a factor of 100 lower mass/volume (16x18x4.5 mm3, 3g) than previous generation 180 GHz receivers.

  3. A high-power LD-pumped linearly polarized Yb-doped fiber laser operating at 1152 nm with 42 GHz narrow linewidth and 18 dB PER

    NASA Astrophysics Data System (ADS)

    Huang, Long; Zhang, Hanwei; Wang, Xiaolin; Su, Rongtao; Zhou, Pu

    2016-07-01

    We demonstrate a high-power 1152 nm narrow-linewidth linearly polarized fiber laser based on a commercial polarization-maintaining double cladding Yb-doped fiber and cladding-pump regime at 976 nm. By carefully selecting the parameters of the cavity and heating the gain fiber, a maximum output power of 13 W with a slope efficiency of ~45% is obtained, with the amplified spontaneous emission suppressed more than 35 dB lower than the signal wavelength. The polarization extinction ratio and 3 dB linewidth at the maximum output power are 18 dB and 0.14 nm (~42 GHz) respectively, while no spectral broadening and polarization degradation are observed in the process of power scaling, which is an attractive result for some special applications, such as frequency doubling.

  4. Design concepts for a high-impedance narrow-band 42 GHz power TWT using a fundamental/forward ladder-based circuit

    NASA Technical Reports Server (NTRS)

    Karp, A.

    1980-01-01

    A low-cost, narrowband, millimeter wave space communications TWT design was studied. Cold test interaction structure scale models were investigated and analyses were undertaken to predict the electrical and thermal response of the hypothetical 200 W TWT at 42 GHz and 21 kV beam voltage. An intentionally narrow instantaneous bandwidth (1%, with the possibility of electronic tuning of the center frequency over several percent) was sought with a highly dispersive, high impedance "forward wave' interaction structure based on a ladder (for economy in fabrication) and nonspace harmonic interaction, for a high gain rate and a short, economically focused tube. The "TunneLadder' interaction structure devised combines ladder properties with accommodation for a pencil beam. Except for the impedance and bandwidth, there is much in common with the millimeter wave helix TWTs which provided the ideal of diamond support rods. The benefits of these are enhanced in the TunneLadder case because of spatial separation of beam interception and RF current heating.

  5. New high-performance complementary bipolar technology featuring 45-GHz NPN and 20-GHz PNP devices

    NASA Astrophysics Data System (ADS)

    Wilson, Martin C.; Osborne, Peter H.; Thomas, Simon; Cook, Trevor

    1999-09-01

    A new high performance silicon complementary bipolar technology is introduced. In addition a novel process 'enhancement' technique based on a local oxidation is described and demonstrated and NPN devices with cut-off frequencies up to 45GHz and PNP devices of 20GHz have been fabricate. We propose that the technique we have used will allow specific transistors within a circuit to be optimized, as required.

  6. Influence of power density on high purity 63 mm diameter polycrystalline diamond deposition inside a 2.45 GHz MPCVD reactor

    NASA Astrophysics Data System (ADS)

    Yu, Shengwang; Wang, Rong; Zheng, Ke; Gao, Jie; Li, Xiaojing; Hei, Hongjun; Liu, Xiaoping; He, Zhiyong; Shen, Yanyan; Tang, Bin

    2016-09-01

    63 mm diameter polycrystalline diamond (PCD) films were synthesized via a microwave plasma chemical vapor deposition (MPCVD) reactor in 99% H2-1% CH4 atmosphere. Two different conditions, i.e. the typical condition (input power of 5 kW and gas pressure of 13 kPa) and the high power density condition (input power of 10 kW and gas pressure of 18 kPa), were employed for diamond depositions. The color changes of the plasma under the two proposed conditions with and without methane were observed by photographs. Likewise, the concentrations of hydrogen atoms and carbon active chemical species in plasma were analyzed by optical emission spectroscopy (OES). The morphologies and purity of the PCD films were investigated by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. Finally, the transmission spectrum of the polished PCD plates was characterized by a UV-Vis-NIR spectrometer. Experimental results showed that both the concentrations of hydrogen atoms and carbon radicals increased obviously, with the boost input power and higher pressure. The films synthesized under the high power density condition displayed higher purity and more uniform thickness. The growth rates in 10 kW and 18 kPa reached ~7.7 µm h-1, approximately 6.5 times as much as that occurred in the typical process. Moreover, the polished plates synthesized under the high power density condition possessed a relatively high optical transmittance (~69%), approaching the theoretical values of approximately 71.4% in IR. These results indicate that the purity and growth rate of big-area PCD films could be simultaneously increased with power density.

  7. A 12 GHz solid state power amplifier, phase 1B

    NASA Astrophysics Data System (ADS)

    Bestwick, P. R.

    1986-05-01

    Attempts to develop a balanced amplifier developing 4 W power output at 12.6 GHz, with a gain of 3.5 dB are summarized. Calculation of the device large-signal conjugate match points, measurement of the points, design and tuning of single-ended amplifier, modules, and a bias insertion network are described. A Lange coupler and a termination for it are presented. The performance of the balanced amplifier, and that of a competing Fujitsu amplifier, are analyzed. The differences in device structure between the PRCL 4820 device and the Fujitsu device are assessed. The amplifier developed gives (at 1 dB gain compression) a gain of 2.4 dB and a power output of 3.2 dB. Difficulties stem from the use of the double-cell 4820 device, and of the Lange type quadrature couplers.

  8. Realizing 60 GHz narrow-linewidth photonic microwaves with very low RF driving power

    NASA Astrophysics Data System (ADS)

    Wei, Weiwei; Lin, Peng; Ke, Shanming; Zeng, Xierong

    2016-12-01

    In this letter, we realize tunable (up to 60 GHz) microwave signal generation with low phase noise (-82.7 dBc Hz-1 with an offset of 10 kHz at 60 GHz) and low RF driving power (⩽2.0 dBm). A monolithically integrated semiconductor dual wavelength laser diode is used, where an enhanced  -3 dB bandwidth of up to 30 GHz is realized with a PP resonance effect. By using an RF signal (ƒmod  =  ƒ/2) to directly modulate the distributed feedback laser section, the dual wavelengths of the laser diode can be locked by the generated sidebands (±2nd order), the beating of which generates a stable microwave signal with high purity.

  9. High Speed sub-GHz Spectrometer for Brillouin Scattering Analysis

    PubMed Central

    Berghaus, Kim; Yun, Seok H.; Scarcelli, Giuliano

    2016-01-01

    Brillouin spectroscopy allows non-contact, direct readout of viscoelastic properties of a material and has been a useful tool in material characterization1, structural monitoring2 and environmental sensing3,4. In the past, Brillouin spectroscopy has usually employed scanning Fabry-Perot etalons to perform spectral analysis which require high illumination power and long acquisition times, which prevents using this technique in biomedical applications. Our newly developed spectrometer overcomes this challenge by employing two virtually imaged phased arrays (VIPAs) in a cross-axis configuration, which enables us to do sub-GHz resolution spectral analysis with sub-seconds acquisition time and illumination power within the safety limits of biological tissue application5. This improvement allows for multiple applications of Brillouin spectroscopy, which are now being broadly explored in biological research and clinical application6. PMID:26779654

  10. On the dependence of the efficiency of a 240 GHz high-power gyrotron on the displacement of the electron beam and on the azimuthal index

    SciTech Connect

    Dumbrajs, O.; Avramidis, K. A.; Franck, J.; Jelonnek, J.

    2014-01-15

    Two issues in the cavity design for a Megawatt-class, 240 GHz gyrotron are addressed. Those are first, the effect of a misaligned electron beam on the gyrotron efficiency and second, a possible azimuthal instability of the gyrotron. The aforementioned effects are important for any gyrotron operation, but could be more critical in the operation of Megawatt-class gyrotrons at frequencies above 200 GHz, which will be the anticipated requirement of DEMO. The target is to provide some basic trends to be considered during the refinement and optimization of the design. Self-consistent calculations are the base for simulations wherever possible. However, in cases for which self-consistent models were not available, fixed-field results are presented. In those cases, the conservative nature of the results should be kept in mind.

  11. High power klystrons for efficient reliable high power amplifiers

    NASA Astrophysics Data System (ADS)

    Levin, M.

    1980-11-01

    This report covers the design of reliable high efficiency, high power klystrons which may be used in both existing and proposed troposcatter radio systems. High Power (10 kW) klystron designs were generated in C-band (4.4 GHz to 5.0 GHz), S-band (2.5 GHz to 2.7 GHz), and L-band or UHF frequencies (755 MHz to 985 MHz). The tubes were designed for power supply compatibility and use with a vapor/liquid phase heat exchanger. Four (4) S-band tubes were developed in the course of this program along with two (2) matching focusing solenoids and two (2) heat exchangers. These tubes use five (5) tuners with counters which are attached to the focusing solenoids. A reliability mathematical model of the tube and heat exchanger system was also generated.

  12. Wideband 220 GHz solid state power amplifier MMIC within minimal die size

    NASA Astrophysics Data System (ADS)

    Cheron, Jerome; Grossman, Erich N.

    2014-05-01

    A wideband and compact solid state power amplifier MMIC is simulated around 220 GHz. It utilizes 6 μm emitter length common base HBTs from a 250 nm InP HBT technology. Specific power cells and power combiners are simulated in order to minimize the width of the die, which must not exceed 300 μm to avoid multimode propagation in the substrate. Four stages are implemented over a total area of the (275x1840) μm2. Simulations of this power amplifier indicate a minimum output power of 14 dBm associated with 16 dB of power gain from 213 GHz to 240 GHz.

  13. Design and Development of Thermistor based Power Meter at 140 GHz Frequency Band

    NASA Astrophysics Data System (ADS)

    Roy, Rajesh; Kush, Abhimanyue Kumar; Dixit, Rajendra Prasad

    2011-12-01

    Design and development of thermistor based power meter at 140 gigahertz (GHz) frequency band have been presented. Power meter comprises power sensor, amplifier circuit and dialog based graphical user interface in visual C++ for the average power measurement. The output power level of a component or system is very critical design factor. Thus there was a need of a power meter for the development of millimeter wave components at 140 GHz frequency band. Power sensor has been designed and developed using NTC (Negative Temperature Coefficient) thermistors. The design aims at developing a direct, simple and inexpensive power meter that can be used to measure absolute power at 140 GHz frequency band. Due to absorption of 140 GHz frequencies, resistance of thermistor changes to a new value. This change in resistance of thermistor can be converted to a dc voltage change and amplified voltage change can be fed to computer through data acquisition card. Dialog based graphical user interface (GUI) has been developed in visual C++ language for average power measurement in dBm. WR6 standard rectangular waveguide is the input port for the sensor of power meter. Temperature compensation has been achieved. Moderate sensor return loss greater than 20 dB has been found over the frequency range 110 to 170 GHz. The response time of the power sensor is 10 second. Average power accuracy is better than ±0.25 dB within the power range from -10 to 10 dBm at 140 GHz frequency band.

  14. A compact high-gradient 25 MeV 17 GHz RF linac for free-electron laser research

    SciTech Connect

    Danly, B.G.; Chen, S.C.; Kreischer, K.E.

    1995-12-31

    A new compact high-gradient (60 MeV/m) high-frequency (17.136 GHz) RF linac is presently under construction by Haimson Research Corp. (HRC) for installation at the MIT Plasma Fusion Center in the High-Gradient Accelerator and High Power Microwave Laboratory. This accelerator will utilize an existing traveling-wave relativistic klystron (TWRK) which is now operation at MIT with 25 MW power, 67 dB gain, and 52% efficiency at 17.136 GHz.

  15. A 20-GHz ultra-high-speed InP DHBT comparator

    NASA Astrophysics Data System (ADS)

    Zhenxing, Huang; Lei, Zhou; Yongbo, Su; Zhi, Jin

    2012-07-01

    An ultra-high-speed, master-slave voltage comparator circuit is designed and fabricated using InP/GaInAs double heterojunction bipolar transistor technology with a current gain cutoff frequency of 170 GHz. The complete chip die, including bondpads, is 0.75 × 1.04 mm2. It consumes 440 mW from a single -4 V power supply, excluding the clock part. 77 DHBTs have been used in the monolithic comparator. A full Nyquist test has been performed up to 20 GHz, with the input sensitivity varying from 6 mV at 10 GHz to 16 mV at 20 GHz. To our knowledge, this is the first InP based integrated circuit including more than 70 DHBTs, and it achieves the highest sampling rate found on the mainland of China.

  16. High Efficiency and Wideband 300 GHz Frequency Doubler Based on Six Schottky Diodes

    NASA Astrophysics Data System (ADS)

    Ding, Jiangqiao; Maestrini, Alain; Gatilova, Lina; Cavanna, Antonella; Shi, Shengcai; Wu, Wen

    2017-07-01

    A high efficiency and wideband 300 GHz frequency doubler based on six Schottky diodes is presented in this paper. This balanced doubler features a compact and robust circuit on a 5-μm-thick, 0.36-mm-wide, and 1-mm-long GaAs membrane, fabricated by LERMA-C2N Schottky process. The conversion efficiency is mainly better than 16% across the wide bandwidth of 266-336 GHz (3 dB fractional bandwidth of 24%) when pumping with 20-60 mW input power (P in) at the room temperature. A peak output power of 14.75 mW at 332 GHz with a 61.18 mW P in, an excellent peak efficiency of 30.5% at 314 GHz with 43.86 mW P in and several frequency points with outstanding efficiency of higher than 25% are delivered. This doubler served as the second stage of the 600 GHz frequency multiplier chain is designed, fabricated, and measured. The performance of this 300 GHz doubler is highlighted comparing to the state-of-art terahertz frequency doublers.

  17. A High Modulation Bandwidth, 110 GHz Power DAC Cell forIQ Transmitter Arrays With Direct Amplitude and PhaseModulation

    DTIC Science & Technology

    2014-06-23

    NUMBER Peter Asbeck Stefan Shopov , Andreea Balteanu, Sorin P. Voinigescu 0720BA c. THIS PAGE The public reporting burden for this collection of...from large signal power and S-parameter phase measurements. Publication Identifier Type: DOI Issue: 1.0E+001 Date Published: Peer Reviewed: Y ...Cell for IQ Transmitter Arrays With Direct Amplitude and Phase Modulation Andreea Balteanu, Student Member, IEEE, Stefan Shopov , Student Member, IEEE

  18. The 20 GHz GaAs monolithic power amplifier module development

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The development of a 20 GHz GaAs FET monlithic power amplifier module for advanced communication applications is described. Four-way power combing of four 0.6 W amplifier modules is used as the baseline approach. For this purpose, a monolithic four-way traveling-wave power divider/combiner was developed. Over a 20 GHz bandwidth (10 to 30 GHz), an insertion loss of no more than 1.2 dB was measured for a pair of back-to-back connected divider/combiners. Isolation between output ports is better than 20 dB, and VSWRs are better than 21:1. A distributed amplifier with six 300 micron gate width FETs and gate and drain transmission line tapers has been designed, fabricated, and evaluated for use as an 0.6 W module. This amplifier has achieved state-of-the-art results of 0.5 W output power with at least 4 dB gain across the entire 2 to 21 GHz frequency range. An output power of 2 W was achieved at a measurement frequency of 18 GHz when four distributed amplifiers were power-combined using a pair of traveling-wave divider/combiners. Another approach is the direct common-source cascading of three power FET stages. An output power of up to 2W with 12 dB gain and 20% power-added efficiency has been achieved with this approach (at 17 GHz). The linear gain was 14 dB at 1 W output. The first two stages of the three-stage amplifier have achieved an output power of 1.6 W with 9 dB gain and 26% power-added efficiency at 16 GHz.

  19. Flexible low-power RF nanoelectronics in the GHz regime using CVD MoS2

    NASA Astrophysics Data System (ADS)

    Yogeesh, Maruthi

    Two-dimensional (2D) materials have attracted substantial interest for flexible nanoelectronics due to the overall device mechanical flexibility and thickness scalability for high mechanical performance and low operating power. In this work, we demonstrate the first MoS2 RF transistors on flexible substrates based on CVD-grown monolayers, featuring record GHz cutoff frequency (5.6 GHz) and saturation velocity (~1.8×106 cm/s), which is significantly superior to contemporary organic and metal oxide thin-film transistors. Furthermore, multicycle three-point bending results demonstrated the electrical robustness of our flexible MoS2 transistors after 10,000 cycles of mechanical bending. Additionally, basic RF communication circuit blocks such as amplifier, mixer and wireless AM receiver have been demonstrated. These collective results indicate that MoS2 is an ideal advanced semiconducting material for low-power, RF devices for large-area flexible nanoelectronics and smart nanosystems owing to its unique combination of large bandgap, high saturation velocity and high mechanical strength.

  20. A 20 GHz, high efficiency dual mode TWT for the ACTS program

    NASA Astrophysics Data System (ADS)

    Muennemann, Frank; Dombro, Louis; Long, Jin

    The development of a 50 W/10 W dual mode K-band downlink TWT is examined, and its performance is evaluated. The designs of the electron gun, RF circuit, and collector for the TWT, which is enclosed in a capsule, are described. It is observed that the high power mode (HPM) power output is at 50 GHz and the low power mode (LPM) output is at 12 GHz; the saturated gain is 52.5 dB for HPM and 3 dB for LPM; the AM-PM is 4.2 dB; the HPM dc power output is 104 W; and the LPM dc output is 42 W; and the efficiency is 45 percent for the HPM and 28.6 percent for the LPM.

  1. An FDMA system concept for 30/20 GHz high capacity domestic satellite service

    NASA Technical Reports Server (NTRS)

    Berk, G.; Jean, P. N.; Rotholz, E.; White, B. E.

    1982-01-01

    The paper summarizes a feasibility study of a multibeam FDMA satellite system operating in the 30/20 GHz band. The system must accommodate a very high volume of traffic within the restrictions of a 5 kW solar cell array and a 2.5 GHz bandwidth. Multibeam satellite operation reduces the DC power demand and allows reuse of the available bandwidth. Interferences among the beams are brought to acceptable levels by appropriate frequency assignments. A transponder design is presented; it is greatly simplified by the application of a regional concept. System analysis shows that MSK modulation is appropriate for a high-capacity system because it conserves the frequency spectrum. Rain attenuation, a serious problem in this frequency band, is combatted with sufficient power margins and with coding. Link budgets, cost analysis, and weight and power calculations are also discussed. A satellite-routed FDMA system compares favorably in performance and cost with a satellite-switched TDMA system.

  2. High power millimeter wave source development program

    NASA Technical Reports Server (NTRS)

    George, T. V.

    1989-01-01

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

  3. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    SciTech Connect

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized.

  4. SECOND SEASON QUIET OBSERVATIONS: MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRUM AT 95 GHz

    SciTech Connect

    Araujo, D.; Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L.; Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.; Chinone, Y.; Cleary, K.; Reeves, R.; Naess, S. K.; Eriksen, H. K.; Wehus, I. K.; Bronfman, L.; Church, S. E.; Dickinson, C.; Gaier, T.; Collaboration: QUIET Collaboration; and others

    2012-12-01

    The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95 GHz. The 43 GHz results have been published in a previous paper, and here we report the measurement of CMB polarization power spectra using the 95 GHz data. This data set comprises 5337 hr of observations recorded by an array of 84 polarized coherent receivers with a total array sensitivity of 87 {mu}K{radical}s. Four low-foreground fields were observed, covering a total of {approx}1000 deg{sup 2} with an effective angular resolution of 12.'8, allowing for constraints on primordial gravitational waves and high signal-to-noise measurements of the E-modes across three acoustic peaks. The data reduction was performed using two independent analysis pipelines, one based on a pseudo-C {sub l} (PCL) cross-correlation approach, and the other on a maximum-likelihood (ML) approach. All data selection criteria and filters were modified until a predefined set of null tests had been satisfied before inspecting any non-null power spectrum. The results derived by the two pipelines are in good agreement. We characterize the EE, EB, and BB power spectra between l = 25 and 975 and find that the EE spectrum is consistent with {Lambda}CDM, while the BB power spectrum is consistent with zero. Based on these measurements, we constrain the tensor-to-scalar ratio to r = 1.1{sup +0.9} {sub -0.8} (r < 2.8 at 95% C.L.) as derived by the ML pipeline, and r = 1.2{sup +0.9} {sub -0.8} (r < 2.7 at 95% C.L.) as derived by the PCL pipeline. In one of the fields, we find a correlation with the dust component of the Planck Sky Model, though the corresponding excess power is small compared to statistical errors. Finally, we derive limits on all known systematic errors, and demonstrate that these correspond to a tensor-to-scalar ratio smaller than r = 0.01, the lowest level yet reported in the literature.

  5. Production of extremely high-lying states by 80-GHz microwave fields

    NASA Astrophysics Data System (ADS)

    Arakelyan, Alexandr; Gallagher, Thomas F.

    2015-05-01

    It was previously reported that ionization of Rydberg atoms of Na and Li by strong microwave (MW) fields of 17 and 38 GHz yields a substantial fraction of population left in the high-lying states with n > 250. This phenomenon was observed for any initial state at least fractionally ionized and was reported as a consequence of MW ionization of atoms. We present results of a similar experiment conducted with an 80-GHz MW field. The production of the high-lying states after the strong 80-GHz pulse is observed, but, in contrast to previous studies, not for any initial state. The high-lying states are only observed if atoms are excited to a zero-field state that is in a multiphoton resonance with the ionization limit (IL). We attribute the difference in the results of 80 and 17-GHz experiments to the fact that the ponderomotive shift is 4 and 90 GHz, respectively, at 100-V/cm. Consequently, we show that the high-lying states are produced if an initial state can be shifted in resonance with the IL. We also report MW ionization thresholds observed at 80 GHz to be much higher than those measured at 15 GHz: a transition to n + 1 state occurs only when big static field is present. Moreover, unlike results of 15-GHz experiment, ionization thresholds depend strongly on the width of the MW pulse. This work has been supported by the National Science Foundation.

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

    NASA Technical Reports Server (NTRS)

    1967-01-01

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

  7. Efficient EM Simulation of GCPW Structures Applied to a 200-GHz mHEMT Power Amplifier MMIC

    NASA Astrophysics Data System (ADS)

    Campos-Roca, Yolanda; Amado-Rey, Belén; Wagner, Sandrine; Leuther, Arnulf; Bangert, Axel; Gómez-Alcalá, Rafael; Tessmann, Axel

    2017-01-01

    The behaviour of grounded coplanar waveguide (GCPW) structures in the upper millimeter-wave range is analyzed by using full-wave electromagnetic (EM) simulations. A methodological approach to develop reliable and time-efficient simulations is proposed by investigating the impact of different simplifications in the EM modelling and simulation conditions. After experimental validation with measurements on test structures, this approach has been used to model the most critical passive structures involved in the layout of a state-of-the-art 200-GHz power amplifier based on metamorphic high electron mobility transistors (mHEMTs). This millimeter-wave monolithic integrated circuit (MMIC) has demonstrated a measured output power of 8.7 dBm for an input power of 0 dBm at 200 GHz. The measured output power density and power-added efficiency (PAE) are 46.3 mW/mm and 4.5 %, respectively. The peak measured small-signal gain is 12.7 dB (obtained at 196 GHz). A good agreement has been obtained between measurements and simulation results.

  8. Efficient EM Simulation of GCPW Structures Applied to a 200-GHz mHEMT Power Amplifier MMIC

    NASA Astrophysics Data System (ADS)

    Campos-Roca, Yolanda; Amado-Rey, Belén; Wagner, Sandrine; Leuther, Arnulf; Bangert, Axel; Gómez-Alcalá, Rafael; Tessmann, Axel

    2017-05-01

    The behaviour of grounded coplanar waveguide (GCPW) structures in the upper millimeter-wave range is analyzed by using full-wave electromagnetic (EM) simulations. A methodological approach to develop reliable and time-efficient simulations is proposed by investigating the impact of different simplifications in the EM modelling and simulation conditions. After experimental validation with measurements on test structures, this approach has been used to model the most critical passive structures involved in the layout of a state-of-the-art 200-GHz power amplifier based on metamorphic high electron mobility transistors (mHEMTs). This millimeter-wave monolithic integrated circuit (MMIC) has demonstrated a measured output power of 8.7 dBm for an input power of 0 dBm at 200 GHz. The measured output power density and power-added efficiency (PAE) are 46.3 mW/mm and 4.5 %, respectively. The peak measured small-signal gain is 12.7 dB (obtained at 196 GHz). A good agreement has been obtained between measurements and simulation results.

  9. 2.5 GHz integrated graphene RF power amplifier on SiC substrate

    NASA Astrophysics Data System (ADS)

    Hanna, T.; Deltimple, N.; Khenissa, M. S.; Pallecchi, E.; Happy, H.; Frégonèse, S.

    2017-01-01

    In this work, we report the design of 2.5 GHz integrated power amplifier based on a graphene FET fabricated with thermal deposition on SiC. In this first large signal study of graphene radiofrequency power amplifiers, a power gain of 8.9 dB is achieved, the maximum reported output power and power added efficiency are 5.1 dBm and 2.2% respectively. Furthermore, graphene and Si CMOS amplifiers are compared; conclusions are drawn towards the technology enhancements to optimize the amplifiers figures of merit.

  10. RF-MEMS for future mobile applications: experimental verification of a reconfigurable 8-bit power attenuator up to 110 GHz

    NASA Astrophysics Data System (ADS)

    Iannacci, J.; Tschoban, C.

    2017-04-01

    RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from  ‑10 dB to  ‑60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3–5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed.

  11. A 32-GHz solid-state power amplifier for deep space communications

    NASA Technical Reports Server (NTRS)

    Wamhof, P. D.; Rascoe, D. L.; Lee, K. A.; Lansing, F. S.

    1994-01-01

    A 1.5-W solid-state power amplifier (SSPA) has been demonstrated as part of an effort to develop and evaluate state-of-the-art transmitter and receiver components at 32 and 35 GHz for future deep space missions. Output power and efficiency measurements for a monolithic millimeter-wave integrated circuit (MMIC)-based SSPA are reported. Technical design details for the various modules and a thermal analysis are discussed, as well as future plans.

  12. In-Phase Power-Combined Frequency Tripler at 300 GHz

    NASA Technical Reports Server (NTRS)

    Maestrini, Alain; Ward, John; Lin, Robert; Gill, John; Lee, Choonsup; Mehdi, Imran; Javadi, Hamid; Chattopadhyay, Goutam

    2009-01-01

    This design starts with commercial 85- to 115-GHz sources that are amplified to as much as 250 mW using power amplifiers developed for the Herschel Space Observatory. The frequency is then tripled using a novel waveguide GaAs Schottky diode frequency tripler. This planar diode produces 26 mW at 318 GHz. Peak conversion efficiency is over 15 percent, and the measured bandwidth of about 265 - 30 GHz is limited more by the driving source than by the tripler itself. This innovation is based on an integrated circuit designed originally for a single-chip 260- to 340-GHz balanced tripler. The power-combined version has two mirror-image tripler chips that are power-combined in-phase in a single waveguide block using a compact Y-junction divider at the input waveguide, and a Y-junction combiner at the output waveguide. The tripler uses a split-block waveguide design with two independent DC bias lines.

  13. Highly efficient Bell state purification and GHZ preparation and purification

    NASA Astrophysics Data System (ADS)

    Krastanov, Stefan; Jiang, Liang

    2016-05-01

    We investigate novel protocols for entanglement purification with Bell states. Employing genetic algorithms for the design of the purification circuit, we obtain shorter circuits giving higher success rates and better final fidelities than what is available in the literature. We generalize these circuits in order to prepare GHZ states from Bell pairs and to subsequently purify these GHZ states. We provide new threshold estimates for codes using these GHZ states for fault-tolerant stabilizer measurements.

  14. Development of a 233 GHz High Gain Traveling Wave Amplifier

    DTIC Science & Technology

    2014-04-22

    USA 2Beam Wave Research, Inc., Bethesda, MD 20814 USA Abstract: We present development plans for a 233 GHz, serpentine waveguide vacuum electron...NRL G-band serpentine waveguide amplifier [2, 3] was the first demonstrated amplifier to use a UV-LIGA fabricated circuit. The small- signal gain...using the same techniques for 231.5 GHz to 235 GHz, an FCC Radiolocation band. Amplifier Design The compound, hybrid serpentine waveguide (SWG

  15. High temperature heat treatment of 3GHz niobium cavities

    SciTech Connect

    Diete, W. ); Rusnak, B.; Bennett, B.L.; Clark, W.L.; Maggs, R.G.; Shapiro, A.H.; Wright, P.V. )

    1992-01-01

    We applied high temperature heat treatment to 3GHz cavities to determine the preparation of niobium cavities using the titanium solid-state gettering process. Some preliminary results showed peak surface electric fields of up to 65MV/m at a Q-factor of 2{times}lO{sup 10}. We evaluated improvement in the purity of the niobium by measuring the residual resistance ratio (RRR) at 10K. The purest niobium we prepared reached a RRR of 670. To study the potential application to large-scale accelerator structures at lower frequencies, we are testing the possibility of heat treating the cavity half-cells before welding them. Therefore, we investigated the influence of electron beam welding on the RRR of high-purity niobium.

  16. Review on high current 2.45 GHz electron cyclotron resonance sources (invited)

    SciTech Connect

    Gammino, S.; Celona, L.; Ciavola, G.; Maimone, F.; Mascali, D.

    2010-02-15

    The suitable source for the production of intense beams for high power accelerators must obey to the request of high brightness, stability, and reliability. The 2.45 GHz off-resonance microwave discharge sources are the ideal device to generate the requested beams, as they produce multimilliampere beams of protons, deuterons, and monocharged ions, remaining stable for several weeks without maintenance. A description of different technical designs will be given, analyzing their strength, and weakness, with regard to the extraction system and low energy beam transport line, as the presence of beam halo is detrimental for the accelerator.

  17. Note: A 95 GHz mid-power gyrotron for medical applications measurements

    NASA Astrophysics Data System (ADS)

    Pilossof, Moritz; Einat, Moshe

    2015-01-01

    A mid-power 95 GHz gyrotron was built and used for measuring insertion loss of biological tissue. The gyrotron is a compact table-top device that allows convenient measurements in a biological setup. It operates at the fundamental harmonic with TE02 circular mode. A mode converter is used to obtain TE10 rectangular mode in standard WR10 components. Using this gyrotron, beef tissue insertion loss was measured to be about 7-8 dB per millimeter.

  18. A High Efficiency Multiple-Anode 260-340 GHz Frequency Tripler

    NASA Technical Reports Server (NTRS)

    Maestrini, Alain; Tripon-Canseliet, Charlotte; Ward, John S.; Gill, John J.; Mehdi, Imran

    2006-01-01

    We report on the fabrication at the Jet Propulsion Laboratory of a fixed-tuned split-block waveguide balanced frequency tripler working in the 260-340 GHz band. This tripler will be the first stage of a x3x3x3 multiplier chain to 2.7 THz (the last stages of which are being fabricated at JPL) and is therefore optimized for high power operation. The multiplier features six GaAs Schottky planar diodes in a balanced configuration integrated on a GaAs membrane. Special attention was put on splitting the input power as evenly as possible among the diodes in order to ensure that no diode is overdriven. Preliminary RF tests indicate that the multiplier covers the expected bandwidth and that the efficiency is in the range 1.5-7.5 % with 100 mW of input power.

  19. Low-power 24.1-GHz propagation effects on roadways

    NASA Astrophysics Data System (ADS)

    Geisheimer, Jonathan L.; Greneker, Eugene F., III; Simas de Oliveria, Marcelo G.

    2001-08-01

    This paper discusses the experimental design and analysis of low power 24.1 GHz propagation effects on roadways around the Atlanta, Georgia metropolitan area. The transmitter used was a 24.1 GHz Safety Warning System (SWS) transmitter operating in the continuous wave (CW) mode. The Federal Communications Commission (FCC) has licensed the Safety Warning System for Part 90 operation. A Part 90-compliant transmitter was used during the tests. The receiver was a modified Bel 855Sti radar detector that was calibrated in an anechoic chamber. The receiver was placed in a Ford F-150 truck and driven toward the transmitter. Three distinct propagation environments are characterized including a rural road, state route, and interstate highway. Shadowing effects from terrain features such as hills are examined as well as the effects of other vehicles, including large tractor-trailers. Signal strength is analyzed as a function of distance to the transmitter and using probability distribution function (pdf) modeling. It was found that the Weibull distribution provided the best statistical description for both the line of sight and shadowing cases. In many instances, the statistics of the received signal would change rapidly depending on the terrain features and interaction with surrounding traffic. The results provide insight into how the unlicensed 24.1 GHz band in the United States might be used for low power, intelligent transportation system (ITS) applications.

  20. Multi-channel 80-GHz RZ pulse train generation based on parametric process in highly-nonlinear fiber

    NASA Astrophysics Data System (ADS)

    Yang, Jing; Hu, Junhao; Yu, Changyuan; Yeo, Yong Kee; Wang, Yixin

    2010-03-01

    It is experimentally shown that six-channel C + L-band 80-GHz short pulse trains are generated based on parametric process in highly-nonlinear fiber (HNLF). By launching a pulsed pump and three-channel continuous wave (CW) lights into 1-km HNLF, three-channel signals are amplified and three-channel idlers are generated. The waveforms of the generated 80-GHz short pulses are measured by an auto-correlator. The bit-error-rate (BER) of each channel is analyzed numerically. In the back-to-back case, the power penalties of the generated channels are less than 1.5-dB.

  1. Area-Efficient 60 GHz +18.9 dBm Power Amplifier with On-Chip Four-Way Parallel Power Combiner in 65-nm CMOS

    NASA Astrophysics Data System (ADS)

    Farahabadi, Payam Masoumi; Basaligheh, Ali; Saffari, Parvaneh; Moez, Kambiz

    2017-02-01

    This paper presents a compact 60-GHz power amplifier utilizing a four-way on-chip parallel power combiner and splitter. The proposed topology provides the capability of combining the output power of four individual power amplifier cores in a compact die area. Each power amplifier core consists of a three-stage common-source amplifier with transformer-coupled impedance matching networks. Fabricated in 65-nm CMOS process, the measured gain of the 0.19-mm2 power amplifier at 60 GHz is 18.8 and 15 dB utilizing 1.4 and 1.0 V supply. Three-decibel band width of 4 GHz and P1dB of 16.9 dBm is measured while consuming 424 mW from a 1.4-V supply. A maximum saturated output power of 18.3 dBm is measured with the 15.9% peak power added efficiency at 60 GHz. The measured insertion loss is 1.9 dB at 60 GHz. The proposed power amplifier achieves the highest power density (power/area) compared to the reported 60-GHz CMOS power amplifiers in 65 nm or older CMOS technologies.

  2. Area-Efficient 60 GHz +18.9 dBm Power Amplifier with On-Chip Four-Way Parallel Power Combiner in 65-nm CMOS

    NASA Astrophysics Data System (ADS)

    Farahabadi, Payam Masoumi; Basaligheh, Ali; Saffari, Parvaneh; Moez, Kambiz

    2017-06-01

    This paper presents a compact 60-GHz power amplifier utilizing a four-way on-chip parallel power combiner and splitter. The proposed topology provides the capability of combining the output power of four individual power amplifier cores in a compact die area. Each power amplifier core consists of a three-stage common-source amplifier with transformer-coupled impedance matching networks. Fabricated in 65-nm CMOS process, the measured gain of the 0.19-mm2 power amplifier at 60 GHz is 18.8 and 15 dB utilizing 1.4 and 1.0 V supply. Three-decibel band width of 4 GHz and P1dB of 16.9 dBm is measured while consuming 424 mW from a 1.4-V supply. A maximum saturated output power of 18.3 dBm is measured with the 15.9% peak power added efficiency at 60 GHz. The measured insertion loss is 1.9 dB at 60 GHz. The proposed power amplifier achieves the highest power density (power/area) compared to the reported 60-GHz CMOS power amplifiers in 65 nm or older CMOS technologies.

  3. 2.4 GHz CMOS Power Amplifier with Mode-Locking Structure to Enhance Gain

    PubMed Central

    2014-01-01

    We propose a mode-locking method optimized for the cascode structure of an RF CMOS power amplifier. To maximize the advantage of the typical mode-locking method in the cascode structure, the input of the cross-coupled transistor is modified from that of a typical mode-locking structure. To prove the feasibility of the proposed structure, we designed a 2.4 GHz CMOS power amplifier with a 0.18 μm RFCMOS process for polar transmitter applications. The measured power added efficiency is 34.9%, while the saturated output power is 23.32 dBm. The designed chip size is 1.4 × 0.6 mm2. PMID:25045755

  4. High-efficiency high-gain monolithic heterostructure FET amplifier at 31 GHz

    NASA Technical Reports Server (NTRS)

    Tserng, H. Q.; Saunier, P.; Kao, Y.-C.

    1993-01-01

    A three-stage heterostructure FET monolithic amplifier has achieved a power-added efficiency of 36 percent with 200 mW output and 18 dB gain at 31 GHz. At a higher drain voltage, the output power increases to 280 mW (with 17.5 dB gain and 31 percent PAE) at a power density of 0.7 W/mm. The MMIC chip measures 2.63 x 1.35 sq mm and requires only a single drain bias and a single gate bias.

  5. A 3 Ghz photoelectron gun for high beam intensity

    SciTech Connect

    Bossart, R.; Braun, H.; Dehler, M.

    1995-12-31

    The CLIC Test Facility (CTF) for new accelerator structures of the proposed Compact Linear Collider (CLIC) is to be equipped with a new RF gun containing a laser driven photocathode. The new 3 GHz gun with photocathode shall produce a bunch train of 48 electron bunches of 25 nC charge each with a bunch length of 8 - 15 ps fwhm. The new RF gun consists of 2{1/2} cells and accelerates the beam to an energy of 7 MeV with a peak field gradient Ez = 100 MV/m. The strong space charge forces at low beam energy caused by the high charge density of the electron bunches must be contained by radial and longitudinal RF focusing in the RF gun. Radial RF focusing is applied by a conical backplane around the photocathode in the first cell where the electrons have a low energy. Longitudinal RF focusing is obtained by varying the length of each of the three cells of the gun. The total electric charge of the bunch train exceeds 1{mu}C and causes strong beam loading to the RF structures so that the stored energy is reduced to half of the unloaded RF energy. The RF gun under construction is being optimized by MAFIA beam simulations for an injector assembly comprising a second accelerating RF structure of 4 cells and an intermediate solenoid magnet correcting the beam divergence of the 2{1/2} cell gun. The scheme with two accelerating RF sections will provide a linear energy increase along the bunch suitable for further compression of the bunch length in a magnetic chicane.

  6. High Power Co-Axial Coupler

    SciTech Connect

    Neubauer, M.; Dudas, A.; Rimmer, Robert A.; Guo, Jiquan; Williams, R. Scott

    2013-12-01

    A very high power Coax RF Coupler (MW-Level) is very desirable for a number of accelerator and commercial applications. For example, the development of such a coupler operating at 1.5 GHz may permit the construction of a higher-luminosity version of the Electron-Ion Collider (EIC) being planned at JLab. Muons, Inc. is currently funded by a DOE STTR grant to develop a 1.5-GHz high-power doublewindowcoax coupler with JLab (about 150 kW). Excellent progress has been made on this R&D project, so we propose an extension of this development to build a very high power coax coupler (MW level peak power and a max duty factor of about 4%). The dimensions of the current coax coupler will be scaled up to provide higher power capability.

  7. Optimized TE01-to-TM11 mode conversion in highly overmoded circular waveguide at 70 and 140 GHz

    NASA Astrophysics Data System (ADS)

    Sturm, H.

    1985-06-01

    Mode coupling in bent, oversized, smoothly walled circular waveguides was studied by numerical integration of coupled-mode equations, to optimize high power TE01-to-TM11 mode transducers at 70 and 140 GHZ. Such transducers are used in the mode conversion sequence TE on to TE01 to TM11 to HE11 to generate the linearly polarized HE11 (Gaussianlike) mode from the circular electric TE on gyrotron mode. The balanced HE11 hydrid mode is ideal for electron cyclotron plasma heating in thermonuclear fusion research and for other technical applications. The lowest level of unwanted spurious modes is achieved with sinusoidal curvature distribution instead of constant curvature. The calculated efficiencies of 98.0% at 70 GHZ and 95.2% at 140 GHZ (inner diameter 27.79 mm, ohmic attenuation included) are in excellent agreement with the measured values (97.6% and 95%) respectively.

  8. The 2x2 quasi-optical power combiner array at 20 GHz

    NASA Technical Reports Server (NTRS)

    Kawasaki, Shigeo; Itoh, Tatsuo

    1992-01-01

    Investigation of a power combiner made of two FET oscillators for an active array are reported. As an approach by a quasi-optical method, a two-dimensional planar array of strongly coupled oscillators by direct connection through a microstrip line is used. In-phase condition between the oscillators as well as in-phase condition of each radiation wave was accomplished by regulating length of feed microstrip lines. The radiation elements of 1 lambda-slot are embedded in a circuit ground plane. At an operation frequency of 20 GHz, in both H- and E-planes, reasonable sigma radiation patterns were obtained which have good agreement with theoretical patterns.

  9. Power Accountability with 1 MW 110 GHz Gyrotron System on the DIII--D Tokamak

    NASA Astrophysics Data System (ADS)

    Zhang, Daqing; Lohr, John; Tooker, J. W.; Ponce, Dan; Callis, R. W.

    1996-11-01

    A new gyrotron system (110 GHz, 1 MW, 2 sec) has been built for the DIII--D tokamak. Before the ECH physics experiments were carried out on DIII--D, the power produced by the gyrotron was measured carefully as well as the power absorbed by parts of the system such as in the gyrotron window, mirror optics unit, miter bends, and dummy loads, for different pulse durations. The maximum output power achieved up to now is 885 kW for 500 msec pulse length. The gyrotron generation efficiency is 37%, very close to the optimum operation parameters, and the whole system's efficiency is 29%. The output mode and frequency of the gyrotron was also measured. Detailed experimental results will be presented.

  10. Cryogenic operation of a 24 GHz MMIC SiGe HBT medium power amplifier

    NASA Astrophysics Data System (ADS)

    Qin, Guoxuan; Jiang, Ningyue; Seo, Jung-Hun; Cho, Namki; Ponchak, George E.; van der Weide, Daniel; Ma, Pingxi; Stetson, Scott; Racanelli, Marco; Ma, Zhenqiang

    2010-12-01

    The performance of a SiGe heterojunction bipolar transistor (HBT) millimetre-wave power amplifier (PA) operating at cryogenic temperature was reported and analysed for the first time. A 24 GHz two-stage medium PA employing common-emitter and common-base SiGe power HBTs in the first and the second stage, respectively, showed a significant power gain increase at 77 K in comparison with that measured at room temperature. Detailed analyses indicate that cryogenic operation of SiGe HBT-based PAs mainly affects (improves) the performance of the SiGe HBTs in the circuits due to transconductance enhancement through magnified, favourable changes of SiGe bandgap due to cooling (ΔEg/kT) and minimized thermal effects, with little influence on the passive components of the circuits.

  11. HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

    SciTech Connect

    Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

    2009-11-01

    The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 +- 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is alpha = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

  12. Development of a high-temperature oven for the 28 GHz electron cyclotron resonance ion source

    SciTech Connect

    Ohnishi, J. Higurashi, Y.; Kidera, M.; Ozeki, K.; Nakagawa, T.

    2014-02-15

    We have been developing the 28 GHz ECR ion source in order to accelerate high-intensity uranium beams at the RIKEN RI-beam Factory. Although we have generated U{sup 35+} beams by the sputtering method thus far, we began developing a high-temperature oven with the aim of increasing and stabilizing the beams. Because the oven method uses UO{sub 2}, a crucible must be heated to a temperature higher than 2000 °C to supply an appropriate amount of UO{sub 2} vapor to the ECR plasma. Our high-temperature oven uses a tungsten crucible joule-heated with DC current of approximately 450 A. Its inside dimensions are ϕ11 mm × 13.5 mm. Since the crucible is placed in a magnetic field of approximately 3 T, it is subject to a magnetic force of approximately 40 N. Therefore, we used ANSYS to carefully design the crucible, which was manufactured by machining a tungsten rod. We could raise the oven up to 1900 °C in the first off-line test. Subsequently, UO{sub 2} was loaded into the crucible, and the oven was installed in the 28 GHz ECR ion source and was tested. As a result, a U{sup 35+} beam current of 150 μA was extracted successfully at a RF power of approximately 3 kW.

  13. A high-sensitivity 135 GHz millimeter-wave imager by compact split-ring-resonator in 65-nm CMOS

    NASA Astrophysics Data System (ADS)

    Li, Nan; Yu, Hao; Yang, Chang; Shang, Yang; Li, Xiuping; Liu, Xiong

    2015-11-01

    A high-sensitivity 135 GHz millimeter-wave imager is demonstrated in 65 nm CMOS by on-chip metamaterial resonator: a differential transmission-line (T-line) loaded with split-ring-resonator (DTL-SRR). Due to sharp stop-band introduced by the metamaterial load, high-Q oscillatory amplification can be achieved with high sensitivity when utilizing DTL-SRR as quench-controlled oscillator to provide regenerative detection. The developed 135 GHz mm-wave imager pixel has a compact core chip area of 0.0085 mm2 with measured power consumption of 6.2 mW, sensitivity of -76.8 dBm, noise figure of 9.7 dB, and noise equivalent power of 0.9 fW/√{HZ } Hz. Millimeter-wave images has been demonstrated with millimeter-wave imager integrated with antenna array.

  14. 24-Way Radial Power Combiner/Divider for 31 to 36 GHz

    NASA Technical Reports Server (NTRS)

    Epp, Larry; Hoppe, Daniel; Khan, Abdur; Kelley, Daniel

    2008-01-01

    The figure shows a prototype radial power-combining waveguide structure, capable of operation at frequencies from 31 to 36 GHz, that features an unusually large number (N = 24) of combining (input) ports. The combination of wide-band operation and large N is achieved by incorporating several enhancements over a basic radial power-combiner design. In addition, the structure can be operated as a power divider by reversing the roles of the input and output ports. In this structure, full-height waveguides at the combining ports are matched in impedance to reduced-height radial waveguides inside the combiner base. This match is effected by impedance-transforming stepped waveguide sections. This matching scheme is essential to achievement of large N because N is limited by the height of the waveguides in the base. Power is coupled from the 24 reduced- height radial waveguides into the TE01 mode of a circular waveguide in the base with the help of a matching post at the bottom of the base. ( TE signifies transverse electric, the first subscript is the azimuthal mode number, and the second subscript is the radial mode number.) More specifically, the matching post matches the reflections from the walls of the 24 reduced-height waveguides and enables the base design to exceed the bandwidth requirement. After propagating along the circular waveguide, the combined power is coupled, via a mode transducer, to a rectangular waveguide output port. The mode transducer is divided into three sections, each sized and shaped as part of an overall design to satisfy the mode-conversion and output-coupling requirements while enabling the circular waveguide to be wide enough for combining the 24 inputs over the frequency range of 31 to 36 GHz. During the design process, it was found that two different rectangular waveguide outputs could be accommodated through modification of only the first section of the mode converter, thereby enabling operation in multiple frequency ranges.

  15. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    NASA Astrophysics Data System (ADS)

    Munroe, Brian J.; Zhang, JieXi; Xu, Haoran; Shapiro, Michael A.; Temkin, Richard J.

    2016-03-01

    We report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG) accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power of up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV /m at a breakdown probability of 1.19 ×10-1 per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90 MV /m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV /m at a breakdown probability of 1.09 ×10-1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.

  16. A low power 2.4 GHz transceiver for ZigBee applications

    NASA Astrophysics Data System (ADS)

    Weiyang, Liu; Jingjing, Chen; Haiyong, Wang; Nanjian, Wu

    2013-08-01

    This paper presents a low power 2.4 GHz transceiver for ZigBee applications. This transceiver adopts low power system architecture with a low-IF receiver and a direct-conversion transmitter. The receiver consists of a new low noise amplifier (LNA) with a noise cancellation function, a new inverter-based variable gain complex filter (VGCF) for image rejection, a passive quadrature mixer, and a decibel linear programmable gain amplifier (PGA). The transmitter adopts a quadrature mixer and a class-B mode variable gain power amplifier (PA) to reduce power consumption. This transceiver is implemented in 0.18 μm CMOS technology. The receiver achieves -95 dBm of sensitivity, 28 dBc of image rejection, and -8 dBm of third-order input intercept point (IIP3). The transmitter can deliver a maximum of +3 dBm output power with PA efficiency of 30%. The whole chip area is less than 4.32 mm2. It only consumes 12.63 mW in receiving mode and 14.22 mW in transmitting mode, respectively.

  17. A 540-640-GHz High-efficiency Four-anode Frequency Tripler

    NASA Technical Reports Server (NTRS)

    Maestrini, Alain; Ward, John S.; Gill, John J.; Javadi, Hamid S.; Schlecht, Erich; Tripon-Canseliet, Charlotte; Chattopadhyay, Goutam; Mehdi, Imran

    2005-01-01

    We report on the design and performance of a broad-band, high-power 540-640-GHz fix-tuned balanced frequency tripler chip that utilizes four planar Schottky anodes. The suspended strip-line circuit is fabricated with a 12-micron-thick support frame and is mounted in a split waveguide block. The chip is supported by thick beam leads that are also used to provide precise RF grounding. At room temperature, the tripler delivers 0.9-1.8 mW across the band with an estimated efficiency of 4.5%-9%. When cooled to 120 K, the tripler provides 2.0-4.2 mW across the band with an estimated efficiency of 8%-12%.

  18. A 540-640-GHz High-efficiency Four-anode Frequency Tripler

    NASA Technical Reports Server (NTRS)

    Maestrini, Alain; Ward, John S.; Gill, John J.; Javadi, Hamid S.; Schlecht, Erich; Tripon-Canseliet, Charlotte; Chattopadhyay, Goutam; Mehdi, Imran

    2005-01-01

    We report on the design and performance of a broad-band, high-power 540-640-GHz fix-tuned balanced frequency tripler chip that utilizes four planar Schottky anodes. The suspended strip-line circuit is fabricated with a 12-micron-thick support frame and is mounted in a split waveguide block. The chip is supported by thick beam leads that are also used to provide precise RF grounding. At room temperature, the tripler delivers 0.9-1.8 mW across the band with an estimated efficiency of 4.5%-9%. When cooled to 120 K, the tripler provides 2.0-4.2 mW across the band with an estimated efficiency of 8%-12%.

  19. A survey of 44-GHz Class I methanol masers toward High Mass Protostellar Objects

    NASA Astrophysics Data System (ADS)

    Berenice Rodríguez Garza, Carolina; Kurtz, Stan

    2016-01-01

    We present preliminary results of 44-GHz Class I methanol maser observations made with the Very Large Array toward a sample of 55 High Mass Protostellar Objects. We found a 44% detection rate of methanol maser emission. We present a statistical description of our results, along with a comparison of the location of the 44-GHz masers with respect to shocked gas, traced by Extended Green Objects seen in the Spitzer/IRAC bands.

  20. A low power low cost 2.45 GHz ECRIS for the production of multiply charged ions

    SciTech Connect

    Schlapp, M.; Trassl, R.; Salzborn, E.; Liehr, M.

    1997-09-01

    A low cost, low power ECR ion source designed for the use on a high voltage platform with limited electrical power available, has been developed. To reduce the power consumption of the source the radial and axial magnetic confinement are produced entirely by permanent magnets. An axial magnetic mirror ratio of 2.7 is obtained by a configuration of two times four block magnets. A radial magnetic field of 0.5 T inside the plasma chamber of 60 mm inner diameter is produced by a hexapole magnet. Microwave power up to 300 watts c/w can be applied to the plasma by using different slow-wave structures which allow the use of a plasma chamber much smaller in diameter than required by the wavelength of the used frequency of 2.45 GHz. The ion source can be operated in different modes either for producing multiply charged ions with intensities up to several hundred e{mu}A or for the production of high intensity beams of singly charged ions, i.e. 6.5 mA of He{sup +}. Applications for the ion source are in crossed beams experiments and as injectors for small accelerators as well as for spectroscopic investigations in the VUV wavelength region.

  1. High Voltage EPC for 94 GHz Klystron for Cloud Profiling Radar

    NASA Astrophysics Data System (ADS)

    Gambarara, Marcello; Ceruti, Luca; Cantamessa, Marco; Bartola, Furio

    2008-09-01

    The Cloud Profiling Radar (CPR) operating at 94 GHz is one of the payload instruments to be flown on the EarthCare mission in the time frame of year 2013. An important part of the CPR is the High Power Transmitter (HPT) that is composed by an Electronic Power Conditioner (EPC) and an Extended Interaction Klystron (EIK).The EIK, developed by CPI-Canada, has been selected as promising radio frequency power transmitter. This EIK is already flying on board of the Cloud Sat satellite and is recognised to be reliable for commercial and military applications throughout the world.This paper will be mainly focused on the EPC, developed in the frame of two subsequent ESA contracts, with particular attentions to the presentation of the activities performed, the design solutions adopted, the testing activities and main achieved performances.The activities of the contracts has been concluded on July 2007 with the realization of an elegant breadboard (EBB) of the EPC (see Fig. 1) that has been extensively tested (both alone and integrated with the EIK) and submitted to an accelerated life test.

  2. Design of a high voltage multi-cavity 35 GHz phase-locked gyrotron oscillator

    NASA Astrophysics Data System (ADS)

    1988-11-01

    This paper describes the design for an experimental high power, phase locked gyrotron oscillator. The electron beam is generated by a 1 MV pulseline accelerator, and the reference signal is provided by a 35 GHz, 20 kW magnetron. The expected output power is in the range of 1 to 10 MW. The design is based on a solid 1 MeV, 100 Amp, 4 mm electron beam with a momentum pitch ratio of 0.75. The locking signal from the magnetron is introduced via a prebunching cavity. A second (passive) bunching cavity is used to increase the locking frequency bandwidth obtainable with a given locking power. The bunching cavities are designed to operate in the fundamental TE 111 cylindrical cavity mode. Some competition from the TE 112 higher order axial mode could not be avoided due to the constraint on the minimum drift tube diameter set by the requirement to propagate the electron beam. The bunching cavities include two axial slots to control the cavity Q factor and suppress competing modes. Additional slots and apertures are used to suppress oscillation in the drift spaces. The output cavity operates in the TE sub 121 mode and is also slotted to reduce competing mode excitation. The maximum phase-locking bandwidth is estimated to be 0.1 percent and the time to achieve phase locked operation is about 20 nsec which is consistent with the pulselength of the NRL VEBA accelerator.

  3. High Power High Efficiency Ka-Band Power Combiners for Solid-State Devices

    NASA Technical Reports Server (NTRS)

    Freeman, Jon C.; Wintucky, Edwin G.; Chevalier, Christine T.

    2006-01-01

    Wide-band power combining units for Ka-band are simulated for use as MMIC amplifier applications. Short-slot couplers as well as magic-tees are the basic elements for the combiners. Wide bandwidth (5 GHz) and low insertion (approx.0.2 dB) and high combining efficiencies (approx.90 percent) are obtained.

  4. A 77–100 GHz power amplifier using 0.1-μm GaAs PHEMT technology

    NASA Astrophysics Data System (ADS)

    Ge, Qin; Liu, Wei; Xu, Bo; Qian, Feng; Yao, Changfei

    2017-03-01

    A wideband MMIC power amplifier at W-band is reported in this letter. The four-stage MMIC, developed using 0.1 μm GaAs pseudomorphic HEMT (PHEMT) technology, demonstrated a flat small signal gain of 12.4 ± 2 dB with a minimum saturated output power (Psat) of 14.2 dBm from 77 to 100 GHz. The typical Psat is better by 16.3 dBm with a flatness of 0.4 dB and the maximum power added efficiency is 6% between 77 and 92 GHz. This result shows that the amplifier delivers output power density of about 470 mW/mm with a total gate output periphery of 100 μm. As far as we know, it is nearly the best power density performance ever published from a single ended GaAs-based PHEMT MMIC at this frequency band.

  5. W-band GaN MMIC PA with 257 mW output power at 86.5 GHz

    NASA Astrophysics Data System (ADS)

    Peng, Xu; Xubo, Song; Yuanjie, Lü; Yuangang, Wang; Shaobo, Dun; Jiayun, Yin; Yulong, Fang; Guodong, Gu; Zhihong, Feng; Shujun, Cai

    2015-08-01

    A three-stage W-band GaN monolithic microwave integrated circuit power amplifier (MMIC PA) is reported. In order to manage coupling effects between all the parts of the W-band MMIC, all matching and bias networks have been first optimized using circuit simulating software and then systematically simulated on 3D full-wave electromagnetic simulator. The fabricated MMIC PA achieves a 257 mW output power at 86.5 GHz in continuous-wave mode, with an associated power added efficiency of 5.4% and an associated power gain of 6.1 dB. The power density is 459 mW/mm. Moreover, the MMIC PA offers over 100 mW in the 83-90 GHz bandwidth. Those performances were measured at drain bias of 12 V. Project supported by the National Natural Science Foundation of China (No. 61306113).

  6. 50 MHz-10 GHz low-power resistive feedback current-reuse mixer with inductive peaking for cognitive radio receiver.

    PubMed

    Vitee, Nandini; Ramiah, Harikrishnan; Chong, Wei-Keat; Tan, Gim-Heng; Kanesan, Jeevan; Reza, Ahmed Wasif

    2014-01-01

    A low-power wideband mixer is designed and implemented in 0.13 µm standard CMOS technology based on resistive feedback current-reuse (RFCR) configuration for the application of cognitive radio receiver. The proposed RFCR architecture incorporates an inductive peaking technique to compensate for gain roll-off at high frequency while enhancing the bandwidth. A complementary current-reuse technique is used between transconductance and IF stages to boost the conversion gain without additional power consumption by reusing the DC bias current of the LO stage. This downconversion double-balanced mixer exhibits a high and flat conversion gain (CG) of 14.9 ± 1.4 dB and a noise figure (NF) better than 12.8 dB. The maximum input 1-dB compression point (P1dB) and maximum input third-order intercept point (IIP3) are -13.6 dBm and -4.5 dBm, respectively, over the desired frequency ranging from 50 MHz to 10 GHz. The proposed circuit operates down to a supply headroom of 1 V with a low-power consumption of 3.5 mW.

  7. 50 MHz–10 GHz Low-Power Resistive Feedback Current-Reuse Mixer with Inductive Peaking for Cognitive Radio Receiver

    PubMed Central

    Reza, Ahmed Wasif

    2014-01-01

    A low-power wideband mixer is designed and implemented in 0.13 µm standard CMOS technology based on resistive feedback current-reuse (RFCR) configuration for the application of cognitive radio receiver. The proposed RFCR architecture incorporates an inductive peaking technique to compensate for gain roll-off at high frequency while enhancing the bandwidth. A complementary current-reuse technique is used between transconductance and IF stages to boost the conversion gain without additional power consumption by reusing the DC bias current of the LO stage. This downconversion double-balanced mixer exhibits a high and flat conversion gain (CG) of 14.9 ± 1.4 dB and a noise figure (NF) better than 12.8 dB. The maximum input 1-dB compression point (P1dB) and maximum input third-order intercept point (IIP3) are −13.6 dBm and −4.5 dBm, respectively, over the desired frequency ranging from 50 MHz to 10 GHz. The proposed circuit operates down to a supply headroom of 1 V with a low-power consumption of 3.5 mW. PMID:25133252

  8. High-frequency resonant tunnelling diode oscillator with high-output power

    NASA Astrophysics Data System (ADS)

    Wang, Jue; Alharbi, Khalid; Ofiare, Afesomeh; Khalid, Ata; Cumming, David; Wasige, Edward

    2015-10-01

    In this paper, a prototype G-band (140 GHz-220 GHz) monolithic microwave integrated circuit (MMIC) resonant tunneling diode (RTD) oscillator is reported. The oscillator employs two In0.53Ga0.47As/AlAs RTD devices in the circuit to increase the output power. The measured output power was about 0.34 mW (-4.7 dBm) at 165.7 GHz, which is the highest power reported for RTD oscillator in G-band frequency range. This result demonstrates the validity of the high frequency/high power RTD oscillator design. It indicates that RTD devices, as one of the terahertz (THz) source candidates, have promising future for room-temperature THz applications in such as imaging, wireless communication and spectroscopy analysis, etc. By optimizing RTD oscillator design, it is expected that considerably higher power (>1 mW) at THz frequencies (>300 GHz) will be obtained.

  9. Coherent continuous-wave dual-frequency high-Q external-cavity semiconductor laser for GHz-THz applications.

    PubMed

    Paquet, Romain; Blin, Stéphane; Myara, Mikhaël; Gratiet, Luc Le; Sellahi, Mohamed; Chomet, Baptiste; Beaudoin, Grégoire; Sagnes, Isabelle; Garnache, Arnaud

    2016-08-15

    We report a continuous-wave highly-coherent and tunable dual-frequency laser emitting at two frequencies separated by 30 GHz to 3 THz, based on compact III-V diode-pumped quantum-well surface-emitting semiconductor laser technology. The concept is based on the stable simultaneous operation of two Laguerre-Gauss transverse modes in a single-axis short cavity, using an integrated sub-wavelength-thick metallic mask. Simultaneous operation is demonstrated theoretically and experimentally by recording intensity noises and beat frequency, and time-resolved optical spectra. We demonstrated a >80  mW output power, diffraction-limited beam, narrow linewidth of <300  kHz, linear polarization state (>45  dB), and low intensity noise class-A dynamics of <0.3% rms, thus opening the path to a compact low-cost coherent GHz to THz source development.

  10. High Power Amplifier and Power Supply

    NASA Technical Reports Server (NTRS)

    Duong, Johnny; Stride, Scot; Harvey, Wayne; Haque, Inam; Packard, Newton; Ng, Quintin; Ispirian, Julie Y.; Waian, Christopher; Janes, Drew

    2008-01-01

    A document discusses the creation of a high-voltage power supply (HVPS) that is able to contain voltages up to -20 kV, keep electrical field strengths to below 200 V/mil (approximately equal to 7.87 kV/mm), and can provide a 200-nanosecond rise/fall time focus modulator swinging between cathode potential of 16.3 kV and -19.3 kV. This HVPS can protect the 95-GHz, pulsed extended interaction klystron (EIK) from arcs/discharges from all sources, including those from within the EIK fs vacuum envelope. This innovation has a multi-winding pulse transformer design, which uses new winding techniques to provide the same delays and rise/fall times (less than 10 nanoseconds) at different potential levels ranging from -20 kV to -16 kV. Another feature involves a high-voltage printed-wiring board that was corona-free at -20 kV DC with a 3- kV AC swing. The corona-free multilayer high-voltage board is used to simulate fields of less than 200 V/mil (approximately equal to 7.87 kV/mm) at 20 kV DC. Drive techniques for the modulator FETs (field-effect transistors) (four to 10 in a series) were created to change states (3,000-V swing) without abrupt steps, while still maintaining required delays and transition times. The packing scheme includes a potting mold to house a ten-stage modulator in the space that, in the past, only housed a four-stage modulator. Problems keeping heat down were solved using aluminum oxide substrate in the high-voltage section to limit temperature rise to less than 10 while withstanding -20 kV DC voltage and remaining corona-free.

  11. High Speed Laser with 100 Ghz Resonance Frequency

    DTIC Science & Technology

    2014-02-28

    practical limit occurs when the detuned master laser encounters the next-order laser modes (i.e. Fabry - Perot modes). Our current DFB slave laser...lasers and vertical- cavity surface-emitting lasers (VCSELs), showing the broad applicability of the technique and that the coupling Q (optical quality...Q-factor, and also increases as the injection power and optical frequency increase. Additionally, we show that lasers with very different cavity

  12. A 1- to 10-GHz downconverter for high-resolution microwave survey

    NASA Technical Reports Server (NTRS)

    Mcwatters, D.

    1994-01-01

    A downconverter was designed, built, and tested for the High Resolution Microwave Survey project. The input frequency range is 1 to 10 GHz with instantaneous bandwidth of 350 MHz and dynamic range of 125 dB/Hz. Requirements were derived for the local oscillators and special design techniques were implemented to achieve the high degree of spectral purity required.

  13. Sub-GHz-resolution C-band Nyquist-filtering interleaver on a high-index-contrast photonic integrated circuit.

    PubMed

    Zhuang, Leimeng; Zhu, Chen; Corcoran, Bill; Burla, Maurizio; Roeloffzen, Chris G H; Leinse, Arne; Schröder, Jochen; Lowery, Arthur J

    2016-03-21

    Modern optical communications rely on high-resolution, high-bandwidth filtering to maximize the data-carrying capacity of fiber-optic networks. Such filtering typically requires high-speed, power-hungry digital processes in the electrical domain. Passive optical filters currently provide high bandwidths with low power consumption, but at the expense of resolution. Here, we present a passive filter chip that functions as an optical Nyquist-filtering interleaver featuring sub-GHz resolution and a near-rectangular passband with 8% roll-off. This performance is highly promising for high-spectral-efficiency Nyquist wavelength division multiplexed (N-WDM) optical super-channels. The chip provides a simple two-ring-resonator-assisted Mach-Zehnder interferometer, which has a sub-cm2 footprint owing to the high-index-contrast Si3N4/SiO2 waveguide, while manifests low wavelength-dependency enabling C-band (> 4 THz) coverage with more than 160 effective free spectral ranges of 25 GHz. This device is anticipated to be a critical building block for spectrally-efficient, chip-scale transceivers and ROADMs for N-WDM super-channels in next-generation optical communication networks.

  14. Development of compact and ultra-high-resolution spectrograph with multi-GHz optical frequency comb

    NASA Astrophysics Data System (ADS)

    Endo, Mamoru; Sukegawa, Takashi; Silva, Alissa; Kobayashi, Yohei

    2014-08-01

    In recent years, a calibration method for an astronomical spectrograph using an optical frequency comb (OFC) with a repetition rate of more than ten GHz has been developed successfully [1-5]. But controlling filtering cavities that are used for thinning out longitudinal modes precludes long term stability. The super-mode noise coming from the fundamental repetition rate is an additional problem. We developed a laser-diode pumped Yb:Y2O3 ceramic oscillator, which enabled the generation of 4-GHz (maximum repetition rate of 6.7 GHz) pulse trains directly with a spectrum width of 7 nm (full-width half-maximum, FWHM), and controlled its optical frequency within a MHz level of accuracy using a beat note between the 4-GHz laser and a 246-MHz Yb-fiber OFC. The optical frequency of the Yb-fiber OFC was phase locked to a Rb clock frequency standard. Furthermore we also built a table-top multi-pass spectrograph with a maximum frequency resolution of 600 MHz and a bandwidth of 1 nm using a large-size high-efficiency transmission grating. The resolution could be changed by selecting the number of passes through the grating. This spectrograph could resolve each longitudinal mode of our 4-GHz OFC clearly, and more than 10% throughput was obtained when the resolution was set to 600 MHz. We believe that small and middle scale astronomical observatories could easily implement such an OFC-calibrated spectrograph.

  15. Observation of 115 GHz high-order harmonic noise-like pulse in Er/Yb-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Lin, Qimeng; Hou, Lei; He, Xin; Sun, Jiang; Lu, Baole; Sun, Bo; Chen, Haowei; Bai, Jintao

    2017-07-01

    We report on an ultrahigh repetition rate harmonic noise-like Er/Yb-doped double-cladding fiber laser that can operate through the nonlinear polarization evolution mechanism. High-order harmonic noise-like pulses (NLPs) with a repetition rate as high as 115 GHz have been generated in fiber lasers. At the cavity dispersion of net anomalous, the noise-like pulse with the full width at half maximum of 15 nm was generated at a central wavelength of 1560 nm, with an output power of 628 mW at the pump power of 8 W. These results could be useful for understanding the generation of higher power and higher repetition rate NLPs in passively mode-locked fiber lasers.

  16. Efficient AlGaN/GaN Linear and Digital-Switch-Mode Power Amplifiers for Operation at 2GHz

    NASA Astrophysics Data System (ADS)

    Maroldt, Stephan; Wiegner, Dirk; Vitanov, Stanislav; Palankovski, Vassil; Quay, Rüdiger; Ambacher, Oliver

    This work addresses the enormous efficiency and linearity potential of optimized AlGaN/GaN high-electron mobility transistors (HEMT) in conventional Doherty linear base-station amplifiers at 2.7GHz. Supported by physical device simulation, the work further elaborates on the use of AlGaN/GaN HEMTs in high-speed current-switch-mode class-D (CMCD)/class-S MMICs for data rates of up to 8Gbit/s equivalent to 2GHz RF-operation. The device needs for switch-mode operation are derived and verified by MMIC results in class-S and class-D operation. To the authors' knowledge, this is the first time 2GHz-equivalent digital-switch-mode RF-operation is demonstrated with GaN HEMTs with high efficiency.

  17. Design of a high perveance ACP gun for the Litton 95 GHz harmonic gyroklystron

    SciTech Connect

    True, R.B.; Bemis, T.M.; Good, G.R.; Scheitrum, G.P.; Higgins, L.L.

    1995-12-31

    This paper describes a new advanced centerpost (ACP) gun for the Litton 95 GHz harmonic gyroklystron which provides roughly four times higher beam current than that available from the original gun. The magnetic focusing structure has been carefully matched to the beam in order to provide a very high quality, low velocity spread, axis-encircling beam. The level of magnetic field in the rf interaction region is consistent with fourth harmonic operation of the device (approximately 8,500 gauss) which allows a conventional solenoid to be used. At an operating voltage of 30 kilovolts and a beam current of 6.4 amps, peak power in the beam from the new gun is 192 kilowatts. At this voltage and current, the perveance of the gun is 1.23 micropervs. Procedures, computer codes, and methodology used to design the gun and magnetic focusing system will be discussed in detail. In design of the magnetic focusing structure, the authors made use of codes POISSON and DEMEOS, in combination with a powerful design method developed by one of the authors (Bemis). The method is based upon Busch`s theorem ;and it will be discussed in the paper. The gun was designed to operate into a .064 inch diameter drift tube for values of {alpha} ranging from 1.2 to 2.0 depending upon the beam voltage. Computed axial velocity spread ({delta}{nu}{sub z}/{nu}{sub z}) achieved so far is just over 2.5 percent which represents an excellent start considering the level of perveance and beam power density. The authors are working to lower this number even further and will report the results of their efforts at the meeting.

  18. Frequency flicker of 2.3 GHz AlN-sapphire high-overtone bulk acoustic resonators

    NASA Astrophysics Data System (ADS)

    Boudot, Rodolphe; Martin, Gilles; Friedt, Jean-Michel; Rubiola, Enrico

    2016-12-01

    We report the detailed characterization of 2.3 GHz AlN-Sapphire high-overtone bulk acoustic resonators (HBARs), with a typical loaded Q-factor of 25-30 × 103, 15-20 dB insertion loss, and resonances separated by about 10 MHz. The temperature coefficient of frequency of HBARs is measured to be about -25 ppm/K. We observe at high-input microwave power a significant distortion of the HBAR resonance lineshape, attributed to non-linear effects. The power-induced fractional frequency variation of the HBAR resonance is measured to be about -5 × 10-10/μW. The residual phase noise of a HBAR is measured in the range of -110 to -130 dBrad2/Hz at 1 Hz Fourier frequency, yielding resonator fractional frequency fluctuations at the level of -205 to -225 dB/Hz at 1 Hz and an ultimate HBAR-limited oscillator Allan deviation about 7 × 10-12 at 1 s integration time. The 1/f noise of the HBAR resonator is found to increase with the input microwave power. A HBAR resonator is used for the development of a low phase noise 2.3 GHz oscillator. An absolute phase noise of -60, -120, and -145 dBrad2/Hz for offset frequencies of 10 Hz, 1 kHz, and 10 kHz, respectively, in excellent agreement with the Leeson effect, is measured.

  19. Power generation in a resonant cavity using a beam bunched at 35 GHz by a free electron laser

    NASA Astrophysics Data System (ADS)

    Donohue, J. T.; Gardelle, J.; Lefevre, T.; Rullier, J. L.; Vermare, C.; Lidia, S. M.; Meurdesoif, Y.

    2000-05-01

    An intense beam of relativistic electrons (800 A, 6.7 MeV) has been bunched at 35 GHz by a free-electron laser, in which output power levels exceeding 100 MW were obtained. The beam was then extracted and transported through a resonant cavity, that was excited by its passage. Microwave power levels of 10 MW were extracted from the cavity, in reasonable agreement with a simple formula which relates power output to known properties of the both beam and cavity.

  20. Real100G.RF: A Fully Packaged 240 GHz Transmitter with In-Antenna Power Combining in 0.13 μm SiGe Technology

    NASA Astrophysics Data System (ADS)

    Malz, Stefan; Goettel, Benjamin; Eisenbeis, Joerg; Boes, Florian; Grzyb, Janusz; Vazquez, Pedro Rodriguez; Zwick, Thomas; Pfeiffer, Ullrich R.

    2017-08-01

    This paper reports on the research activities during the first phase of the project Real100G.RF, which is part of the German Research Foundation (DFG) priority programm SPP1655. The project's main objective is to research silicon-based wireless communication above 200 GHz to enable data rates in excess of 100 gigabit per second (Gbps). To that end, this paper presents a fully packaged 240 GHz RF transmitter front-end with power combining antenna in 0.13 μm SiGe technology. The design of circuit building blocks, passives, antenna and high-speed packaging is discussed. Communication measurements show data rates of 8 Gbps with an EVM of 12.4% using 16-QAM, 24 Gbps with 26.5% EVM using QPSK and 30 Gbps with 27.9% EVM using 8-PSK.

  1. High-power photodetector modules for microwave photonic applications

    NASA Astrophysics Data System (ADS)

    Li, Kejia; Xie, Xiaojun; Rouvalis, Efthymios; Fedderwitz, Sascha; Steffan, Andreas G.; Li, Qinglong; Yang, Zhanyu; Beling, Andreas; Campbell, Joe C.

    2015-03-01

    Recently, microwave photonic techniques have emerged to address the challenges that microwave systems face under high-frequency or wideband conditions. To a large extent, the performance of microwave photonic systems depends on the performance of individual optoelectronics devices, such as high power photodiodes. Here, we report a fullypackaged photodetector module based on InGaAs/InP modified uni-traveling carrier (MUTC) photodiode. The modules demonstrated a 3-dB bandwidth up to 50GHz and a record-high output power of 14.0 dBm at 50GHz.

  2. High Efficiency Microwave Power Amplifier (HEMPA) Design

    NASA Technical Reports Server (NTRS)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  3. High-power Ka-band amplifier

    NASA Technical Reports Server (NTRS)

    Cormier, R.

    1993-01-01

    Development of a high-power tube suitable to power a Ka-band (34.5-GHz) antenna transmitter located at the Goldstone, California, tracking station is continuing. The University of Maryland Laboratory for Plasma Research and JPL are conducting a joint effort to test the feasibility of phase locking a second-harmonic gyrotron both by direct injection at the output cavity and by using a priming cavity to bunch the electrons in the beam. This article describes several design options and the results of computer simulation testing.

  4. High power microwave components for space communications satellite

    NASA Technical Reports Server (NTRS)

    Jankowski, H.; Geia, A.

    1972-01-01

    Analyzed, developed, and tested were high power microwave components for communications satellites systems. Included were waveguide and flange configurations with venting, a harmonic filter, forward and reverse power monitors, electrical fault sensors, and a diplexer for two channel simultaneous transmission. The assembly of 8.36 GHz components was bench tested, and then operated for 60 hours at 3.5 kW CW in a high vacuum. The diplexer was omitted from this test pending a modification of its end irises. An RF leakage test showed only that care is required at flange junctions; all other components were RF tight. Designs were extrapolated for 12 GHz and 2.64 GHz high power satellite systems.

  5. High Power Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Jankovsky, Robert; Tverdokhlebov, Sergery; Manzella, David

    1999-01-01

    The development of Hall thrusters with powers ranging from tens of kilowatts to in excess of one hundred kilowatts is considered based on renewed interest in high power. high thrust electric propulsion applications. An approach to develop such thrusters based on previous experience is discussed. It is shown that the previous experimental data taken with thrusters of 10 kW input power and less can be used. Potential mass savings due to the design of high power Hall thrusters are discussed. Both xenon and alternate thruster propellant are considered, as are technological issues that will challenge the design of high power Hall thrusters. Finally, the implications of such a development effort with regard to ground testing and spacecraft intecrati'on issues are discussed.

  6. A 1 watt GaAs power amplifier for the NASA 30/20 GHz communication system

    NASA Technical Reports Server (NTRS)

    Goel, J.; Oransky, G.; Yuan, S.; Osullivan, P.; Burch, J.

    1982-01-01

    A multistage GaAs FET power amplifier, employing cascaded balanced stages using state-of-the-art 1/4, 1/2, and 1 watt devices, has been developed. A linear gain of 30 dB with 1.25 watts output has been achieved over a 17.7 to 19.4 GHz frequency band. The development and performance of the amplifier and its components are discussed.

  7. CSTI high capacity power

    SciTech Connect

    Winter, J.M.

    1994-09-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase I of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY88, the Advanced Technology Program was incorporated into NASA`s new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  8. CSTI High Capacity Power

    NASA Technical Reports Server (NTRS)

    Winter, Jerry M.

    1989-01-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  9. Conceptual definition of a high voltage power supply test facility

    NASA Technical Reports Server (NTRS)

    Biess, John J.; Chu, Teh-Ming; Stevens, N. John

    1989-01-01

    NASA Lewis Research Center is presently developing a 60 GHz traveling wave tube for satellite cross-link communications. The operating voltage for this new tube is - 20 kV. There is concern about the high voltage insulation system and NASA is planning a space station high voltage experiment that will demonstrate both the 60 GHz communications and high voltage electronics technology. The experiment interfaces, requirements, conceptual design, technology issues and safety issues are determined. A block diagram of the high voltage power supply test facility was generated. It includes the high voltage power supply, the 60 GHz traveling wave tube, the communications package, the antenna package, a high voltage diagnostics package and a command and data processor system. The interfaces with the space station and the attached payload accommodations equipment were determined. A brief description of the different subsystems and a discussion of the technology development needs are presented.

  10. Four-to-one power combiner for 20 GHz phased array antenna using RADC MMIC phase shifters

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The design and microwave simulation of two-to-one microstrip power combiners is described. The power combiners were designed for use in a four element phase array receive antenna subarray at 20 GHz. Four test circuits are described which were designed to enable testing of the power combiner and the four element phased array antenna. Test Circuit 1 enables measurement of the two-to-one power combiner. Test Circuit 2 enables measurement of the four-to-one power combiner. Test Circuit 3 enables measurement of a four element antenna array without phase shifting MMIC's in order to characterize the power combiner with the antenna patch-to-microstrip coaxial feedthroughs. Test circuit 4 is the four element phased array antenna including the RADC MMIC phase shifters and appropriate interconnects to provide bias voltages and control phase bits.

  11. 30 GHz Commercial Satellite Receivers

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Ponchak, George E.; Romanofsky, Robert R.

    1989-01-01

    NASA's research and development work in satellite communications for the past 10 years has included a major technology thrust aimed at opening the Ka frequency band to commercial exploitation. This has included the development and testing of advanced system network architectures, on-board switching and processing, multibeam and phased array antennas, and satellite and ground terminal RF and digital hardware. Development work in system hardware has focused on critical components including power amplifiers, satellite IF switch matrices, low noise receivers, baseband processors, and high data rate bandwidth efficient modems. This paper describes NASA's work in developing and testing 30 GHz low noise satellite receivers for commercial space communications uplink applications. Frequencies allotted for fixed service commercial satellite communications in the Ka band are 27.5 - 30.0 GHz for uplink transmission and 17.7 - 20.2 GHz for downlink transmission. The relatively large 2.5 GHz bandwidth lends itself to wideband, high data rate digital transmission applications.

  12. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    NASA Astrophysics Data System (ADS)

    Ali, Mohammed H.; Chakrabarty, C. K.; Abdalla, Ahmed N.; Hock, Goh C.

    2013-06-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  13. High power laser dump

    NASA Astrophysics Data System (ADS)

    Hsu, M. S.; Hsu, J. P.

    1985-08-01

    A high power laser dump has defined laser beam introduction angles to the internal surface of a cylinder to maximize energy dispersion and absorption and, has two zones formed of distinctive reflective and absorbing materials.

  14. A high-finesse sub-GHz-resolution spectrometer employing VIPA etalons of different dispersion

    PubMed Central

    Berghaus, Kim; Zhang, Jitao; Yun, Seok H.; Scarcelli, Giuliano

    2016-01-01

    We report a novel configuration of a two-stage VIPA spectrometer that enables high-throughput sub-GHz spectroscopy at a high finesse (>750). Two etalons with different free spectral range and different dispersion are arranged in orthogonal directions and spread the spectrum in two dimensions with a greatly improved rejection ratio of white-light background noise. A proof-of-concept application for Brillouin spectroscopy is demonstrated. PMID:26421550

  15. 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.

  16. A high-overtone bulk acoustic wave resonator-oscillator-based 4.596 GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock

    SciTech Connect

    Daugey, Thomas; Friedt, Jean-Michel; Martin, Gilles; Boudot, Rodolphe

    2015-11-15

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596 GHz frequency source. A 2.298 GHz signal, generated by an oscillator constructed around a thermally controlled two-port aluminum nitride-sapphire HBAR resonator with a Q-factor of 24 000 at 68 °C, is frequency multiplied by 2–4.596 GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency of the HBAR is measured to be −23 ppm/ °C at 2.298 GHz. The measured phase noise of the 4.596 GHz source is −105 dB rad{sup 2}/Hz at 1 kHz offset and −150 dB rad{sup 2}/Hz at 100 kHz offset. The 4.596 GHz output signal is used as a local oscillator in a laboratory-prototype Cs microcell-based coherent population trapping atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter implemented in the 2.298 GHz HBAR-oscillator loop, preventing the need for a high-power-consuming direct digital synthesis. The short-term fractional frequency stability of the free-running oscillator is 1.8 × 10{sup −9} at one second integration time. In locked regime, the latter is improved in a preliminary proof-of-concept experiment at the level of 6.6 × 10{sup −11} τ{sup −1/2} up to a few seconds and found to be limited by the signal-to-noise ratio of the detected CPT resonance.

  17. A high-overtone bulk acoustic wave resonator-oscillator-based 4.596 GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock

    NASA Astrophysics Data System (ADS)

    Daugey, Thomas; Friedt, Jean-Michel; Martin, Gilles; Boudot, Rodolphe

    2015-11-01

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596 GHz frequency source. A 2.298 GHz signal, generated by an oscillator constructed around a thermally controlled two-port aluminum nitride-sapphire HBAR resonator with a Q-factor of 24 000 at 68 °C, is frequency multiplied by 2-4.596 GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency of the HBAR is measured to be -23 ppm/ °C at 2.298 GHz. The measured phase noise of the 4.596 GHz source is -105 dB rad2/Hz at 1 kHz offset and -150 dB rad2/Hz at 100 kHz offset. The 4.596 GHz output signal is used as a local oscillator in a laboratory-prototype Cs microcell-based coherent population trapping atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter implemented in the 2.298 GHz HBAR-oscillator loop, preventing the need for a high-power-consuming direct digital synthesis. The short-term fractional frequency stability of the free-running oscillator is 1.8 × 10-9 at one second integration time. In locked regime, the latter is improved in a preliminary proof-of-concept experiment at the level of 6.6 × 10-11 τ-1/2 up to a few seconds and found to be limited by the signal-to-noise ratio of the detected CPT resonance.

  18. High-Frequency Wireless Communications System: 2.45-GHz Front-End Circuit and System Integration

    ERIC Educational Resources Information Center

    Chen, M.-H.; Huang, M.-C.; Ting, Y.-C.; Chen, H.-H.; Li, T.-L.

    2010-01-01

    In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end…

  19. High-Frequency Wireless Communications System: 2.45-GHz Front-End Circuit and System Integration

    ERIC Educational Resources Information Center

    Chen, M.-H.; Huang, M.-C.; Ting, Y.-C.; Chen, H.-H.; Li, T.-L.

    2010-01-01

    In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end…

  20. Estimation of Transmitting Power to Compensate for Rain Attenuation for a Broadcasting Satellite System in the 21-GHz Band

    NASA Astrophysics Data System (ADS)

    Minematsu, Fumiaki; Tanaka, Shoji; Nakagawa, Hitoshi; Kawaguchi, Yutaka

    2002-01-01

    1. INTRODUCTION Rain attenuation in the 21-GHz band is much larger than that in the conventionally used 12-GHz band and the rain attenuation causes more serious program interruptions compared with that in the 12-GHz band. We are now studying an advanced broadcasting satellite in the 21-GHz band that enables adaptive compensation for heavy rain area by boosted beams using an on-board phased-array-transmitting antenna. To know the scale of this satellite system, it is important to estimate transmitting power needed to compensate for rain attenuation. Rain attenuation has so close association with rainfall that it is possible to estimate rain attenuation by measured rainfall. Japan meteorological agency is measuring 1-hour rainfalls for about 1300 locations in Japan. In this study, 1-hour rainfall data accumulated at more than 1000 locations over a period of 20 years were used statistically to grasp rainfall distribution throughout Japan and the transmitting power for compensation was estimated by use of these data. 2. CALCULATION MODEL FOR TRANSMITTING POWER ESTIMATION Assumed rain attenuation compensation area for Japanese archipelago was divided into 112 square areas. A size of each square was 0.1 degree in terms of azimuth and elevation angle for the beam direction of satellite transmitting antenna. For calculation, the link margin of 3.5 dB for clear sky was given to the area where 1-hour rainfall not larger than 3 mm was detected. For other square areas where 1-hour rainfall larger than 3 mm was detected, the link margin of 12 dB was given. The former link margin corresponds to the service availability of 99 % and the latter does to that of 99.9 % in an average year in Tokyo. A total system efficiency included radiation efficiency of the transmitting antenna of 1.0 was assumed. As modulation scheme, trellis coded 8-PSK (TC8PSK) was assumed. The required reception CN ratio for TC8PSK is 10.7 dB. As to TC8PSK, the baud rate of 57.72 Mbaud gives more than 100 Mbps

  1. Lightning control system using high power microwave FEL

    SciTech Connect

    Shiho, M.; Watanbe, A.; Kawasaki, S.

    1995-12-31

    A research project for developing a thunder lightning control system using an induction linac based high power microwave free electron laser (FEL) started at JAERI The system will produce weakly ionized plasma rod in the atmosphere by high power microwaves and control a lightning path, away from , e. g., nuclear power stations and rocket launchers. It has been known that about MW/cm{sup 2} power density is enough for the atmospheric breakdown in the microwave region, and which means high power microwave FEL with GW level output power is feasible for atmospheric breakdown, and accordingly is feasible for thunder lightning control tool with making a conductive plasma channel in the atmosphere. From the microwave attenuation consideration in the atmosphere, FEL of 35GHz(0.13dB/km), 90GHz(0.35dB/km), 140GHz(1.7dB/km), and of 270 GHz(4.5dB/km) are the best candidates for the system. Comparing with other proposed lightning control system using visible or ultraviolet laser, the system using microwave has an advantage that microwave suffers smaller attenuation by rain or snow which always exist in the real atmospheric circumstances when lightning occurs.

  2. High power microwave generator

    DOEpatents

    Ekdahl, Carl A.

    1986-01-01

    A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

  3. High power microwave generator

    DOEpatents

    Ekdahl, C.A.

    1983-12-29

    A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

  4. AlGaN/GaN-HEMTs with a breakdown voltage higher than 100 V and maximum oscillation frequency f{sub max} as high as 100 GHz

    SciTech Connect

    Mokerov, V. G. Kuznetsov, A. L.; Fedorov, Yu. V.; Bugaev, A. S.; Pavlov, A. Yu.; Enyushkina, E. N.; Gnatyuk, D. L.; Zuev, A. V.; Galiev, R. R.; Ovcharenko, E. N.; Sveshnikov, Yu. N.; Tsatsulnikov, A. F.; Ustinov, V. M.

    2009-04-15

    The N-Al{sub 0.27}Ga{sub 0.73}N/GaN High Electron Mobility Transistors (HEMTs) with different gate lengths L{sub g} (ranging from 170 nm to 0.5 {mu}m) and gate widths W{sub s} (ranging from 100 to 1200 {mu}m) have been studied. The S parameters have been measured; these parameters have been used to determine the current-gain cutoff frequency f{sub t}, the maximum oscillation frequency f{sub max}, and the power gain MSG/MAG and Mason's coefficients were investigated in the frequency range from 10 MHz to 67 GHz in relation to the gate length and gate width. It was found that the frequencies f{sub t} and f{sub max} attain their maximum values of f{sub t} = 48 GHz and f{sub max} = 100 GHz at L{sub g} = 170 nm and W{sub g} = 100 {mu}m. The optimum values of W{sub g} and output power P out of the basic transistors have been determined for different frequencies of operation. It has also been demonstrated that the 170 nm Al{sub 0.27}Ga{sub 0.73}N/GaN HEMT technology provides both good frequency characteristics and high breakdown voltages and is very promising for high-frequency applications (up to 40 GHz)

  5. High-power flip-chip mounted photodiode array.

    PubMed

    Cross, Allen S; Zhou, Qiugui; Beling, Andreas; Fu, Yang; Campbell, Joe C

    2013-04-22

    Four-element modified uni-traveling-carrier (MUTC) photodiode arrays (PDA) flip-chip bonded onto transmission lines on AlN substrates are demonstrated. High RF output powers of 26.2 dBm and 21.0 dBm are achieved at 35 GHz and 48 GHz, respectively, using a PDA with 28-μm diameter photodiodes. A systematic comparison between a PDA with four 20 μm-diameter elements and a discrete detector with the same active area (40-μm diameter) is presented. The PDA achieved higher output power and thermal dissipation compared to its discrete counterpart.

  6. Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz

    NASA Technical Reports Server (NTRS)

    Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.; Cooperrider, Joelle T.; Bruneau, Peter J.; Kurdoghlian, Ara; Micovic, Miroslav

    2011-01-01

    Future remote sensing instruments will require focal plane spectrometer arrays with higher resolution at high frequencies. One of the major components of spectrometers are the local oscillator (LO) signal sources that are used to drive mixers to down-convert received radio-frequency (RF) signals to intermediate frequencies (IFs) for analysis. By advancing LO technology through increasing output power and efficiency, and reducing component size, these advances will improve performance and simplify architecture of spectrometer array systems. W-band power amplifiers (PAs) are an essential element of current frequency-multiplied submillimeter-wave LO signal sources. This work utilizes GaN monolithic millimeter-wave integrated circuit (MMIC) PAs developed from a new HRL Laboratories LLC 0.15- m gate length GaN semiconductor transistor. By additionally waveguide power combining PA MMIC modules, the researchers here target the highest output power performance and efficiency in the smallest volume achievable for W-band.

  7. High-power high-linearity flip-chip bonded modified uni-traveling carrier photodiode.

    PubMed

    Li, Zhi; Fu, Yang; Piels, Molly; Pan, Huapu; Beling, Andreas; Bowers, John E; Campbell, Joe C

    2011-12-12

    We demonstrate a flip-chip bonded modified uni-traveling carrier (MUTC) photodiode with an RF output power of 0.75 W (28.8 dBm) at 15 GHz and OIP3 as high as 59 dBm. The photodiode has a responsivity of 0.7 A/W, 3-dB bandwidth > 15 GHz, and saturation photocurrent > 180 mA at 11 V reverse bias.

  8. A high-sensitivity 6.7 GHz methanol maser survey toward H2O sources

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Li, J. J.; Hachisuka, K.; Pandian, J. D.; Menten, K. M.; Henkel, C.

    2008-07-01

    We present the results of a high sensitivity survey for 6.7 GHz methanol masers towards 22 GHz water masers using the 100 m Efflesberg telescope. A total of 89 sources were observed and 10 new methanol masers were detected. The new detections are relatively faint with peak flux densities of between 0.5 and 4.0 Jy. A nil detection rate from low-mass star forming regions enhances the conclusion that the masers are only associated with massive star formation. Even the faintest methanol maser in our survey, with a luminosity of 1.1 × 10-9 L_⊙, is associated with massive stars, as inferred from its infrared luminosity. Table 3 is only available in electronic form at http://www.aanda.org

  9. Design of a 75-140 GHz high-pass printed circuit board dichroic filter

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

    A new high-performing PCB (Printed Circuit Board) dichroic filter, which can be used for the KSTAR (Korea Superconducting Tokamak Advanced Research) electron cyclotron emission imaging system, is proposed. The current dichroic filter consists of a triangular lattice array of circular holes on the 6-mm thick metal plate, while circular hole spacing limitation caused relatively narrow passband (˜20 GHz). On the other hand, the proposed PCB dichroic filter utilizes the inexpensive commercial PCB fabrication process with a flexible adjustment of circular hole spacing. Therefore, the proposed PCB dichroic filter provides significantly wider passband (˜60 GHz with 0.84 dB insertion loss) with much reduced weight and expense. Also, it is shown that a steep skirt property can be obtained with the thick PCB filter substrate. The design process, fabrication, and measurement results of the new PCB dichroic filter are described.

  10. Design of a 75-140 GHz high-pass printed circuit board dichroic filter.

    PubMed

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

    2017-03-01

    A new high-performing PCB (Printed Circuit Board) dichroic filter, which can be used for the KSTAR (Korea Superconducting Tokamak Advanced Research) electron cyclotron emission imaging system, is proposed. The current dichroic filter consists of a triangular lattice array of circular holes on the 6-mm thick metal plate, while circular hole spacing limitation caused relatively narrow passband (∼20 GHz). On the other hand, the proposed PCB dichroic filter utilizes the inexpensive commercial PCB fabrication process with a flexible adjustment of circular hole spacing. Therefore, the proposed PCB dichroic filter provides significantly wider passband (∼60 GHz with 0.84 dB insertion loss) with much reduced weight and expense. Also, it is shown that a steep skirt property can be obtained with the thick PCB filter substrate. The design process, fabrication, and measurement results of the new PCB dichroic filter are described.

  11. High power density targets

    NASA Astrophysics Data System (ADS)

    Pellemoine, Frederique

    2013-12-01

    In the context of new generation rare isotope beam facilities based on high-power heavy-ion accelerators and in-flight separation of the reaction products, the design of the rare isotope production targets is a major challenge. In order to provide high-purity beams for science, high resolution is required in the rare isotope separation. This demands a small beam spot on the production target which, together with the short range of heavy ions in matter, leads to very high power densities inside the target material. This paper gives an overview of the challenges associated with this high power density, discusses radiation damage issues in targets exposed to heavy ion beams, and presents recent developments to meet some of these challenges through different projects: FAIR, RIBF and FRIB which is the most challenging. Extensive use of Finite Element Analysis (FEA) has been made at all facilities to specify critical target parameters and R&D work at FRIB successfully retired two major risks related to high-power density and heavy-ion induced radiation damage.

  12. Series of powerful CW gyrotrons in the range 105 - 140 GHz

    NASA Astrophysics Data System (ADS)

    Denisov, Gregory; Kazansky, Igor; Malygin, Vladimir; Soluyanova, Elena; Tai, Evgeny; Chirkov, Aleksey

    2017-07-01

    GYCOM in collaboration with Institute of Applied Physics (IAP) designed, fabricated and tested two different gyrotrons with similar to ITER parameters at 105 - 140 GHz frequency range. Set of gyrotron system beside the tube includes matching optic unit (MOU) and elements of evacuated transmission lines. One gyrotron system was installed and operates at plasma machines EAST / ASIPP / China, another system is delivered to KSTAR / NFRI / Korea.

  13. MMIC Power Amplifier Puts Out 40 mW From 75 to 110 GHz

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene

    2006-01-01

    A three-stage monolithic microwave integrated circuit (MMIC) W-band amplifier has been constructed and tested in a continuing effort to develop amplifiers as well as oscillators, frequency multipliers, and mixers capable of operating over wide frequency bands that extend above 100 GHz. There are numerous potential uses for MMICs like these in scientific instruments, radar systems, communication systems, and test equipment operating in this frequency range.

  14. GaAs-based JFET and PHEMT technologies for ultra-low-power microwave circuits operating at frequencies up to 2.4 GHz

    SciTech Connect

    Baca, A.G.; Hietala, V.M.; Greenway, D.; Shul, R.J.; Hafich, M.J.; Zolper, J.C.; Sherwin, M.E.

    1998-05-01

    In this work the authors report results of narrowband amplifiers designed for milliwatt and submilliwatt power consumption using JFET and pseudomorphic high electron mobility transistors (PHEMT) GaAs-based technologies. Enhancement-mode JFETs were used to design both a hybrid amplifier with off-chip matching as well as a monolithic microwave integrated circuit (MMIC) with on-chip matching. The hybrid amplifier achieved 8--10 dB of gain at 2.4 GHz and 1 mW. The MMIC achieved 10 dB of gain at 2.4 GHz and 2 mW. Submilliwatt circuits were also explored by using 0.25 {micro}m PHEMTs. 25 {micro}W power levels were achieved with 5 dB of gain for a 215 MHz hybrid amplifier. These results significantly reduce power consumption levels achievable with the JFETs or prior MESFET, heterostructure field effect transistor (HFET), or Si bipolar results from other laboratories.

  15. Effects of 60-GHz millimeter waves on neurite outgrowth in PC12 cells using high-content screening.

    PubMed

    Haas, Alexis J; Le Page, Yann; Zhadobov, Maxim; Sauleau, Ronan; Le Dréan, Yves

    2016-04-08

    Technologies for wireless telecommunication systems using millimeter waves (MMW) will be widely deployed in the near future. Forthcoming applications in this band, especially around 60GHz, are mainly developed for high data-rate local and body-centric telecommunications. At those frequencies, electromagnetic radiations have a very shallow penetration into biological tissues, making skin keratinocytes, and free nerve endings of the upper dermis the main targets of MMW. Only a few studies assessed the impact of MMW on neuronal cells, and none of them investigated a possible effect on neuronal differentiation. We used a neuron-like cell line (PC12), which undergoes neuronal differentiation when treated with the neuronal growth factor (NGF). PC12 cells were exposed at 60.4GHz for 24h, at an incident power density averaged over the cell monolayer of 10mW/cm(2). Using a large scale cell-by-cell analysis based on high-content screening microscopy approach, we assessed potential effects of MMW on PC12 neurite outgrowth and cytoskeleton protein expression. No differences were found in protein expression of the neuronal marker β3-tubulin nor in internal expression control β-tubulin. On the other hand, our data showed a slight increase, although insignificant, in neurite outgrowth, induced by MMW exposure. However, experimental controls demonstrated that this increase was related to heating.

  16. High power local ECH in CHS

    SciTech Connect

    Kubo, S.; Idei, H.; Iwase, M.; Ohkubo, K.; Minami, T.; Yamada, I.; Narihara, K.; Tanaka, K.; Wilgen, J.B.; Murakami, M.; Rasumussen, D.A.; Nishimura, K.; Okamura, S.; Matsuoka, K.

    1996-02-01

    Electron cyclotron heating (ECH) experiments with 200 kW and 400 kW gyrotrons at the frequency of 53.2 GHz have been performed in Compact Helical System (CHS). Microwave power from both gyrotrons is transmitted with quasi-optical transmission line and highly focused on the mid-plane of CHS. The main purpose of these experiments is to understand the heating and energy transport mechanisms in CHS at the low collisional regime. The combination of the magnetic field, focal position and polarization enables the investigation of the on/off axis local heating effect with fundamental and second harmonic ECH. {copyright} {ital 1996 American Institute of Physics.}

  17. Micropillar Resonators for Optomechanics in the Extremely High 19-95-GHz Frequency Range

    NASA Astrophysics Data System (ADS)

    Anguiano, S.; Bruchhausen, A. E.; Jusserand, B.; Favero, I.; Lamberti, F. R.; Lanco, L.; Sagnes, I.; Lemaître, A.; Lanzillotti-Kimura, N. D.; Senellart, P.; Fainstein, A.

    2017-06-01

    Strong confinement, in all dimensions, and high mechanical frequencies are highly desirable for quantum optomechanical applications. We show that GaAs/AlAs micropillar cavities fully confine not only photons but also extremely high frequency (19-95 GHz) acoustic phonons. A strong increase of the optomechanical coupling upon reducing the pillar size is observed, together with record room-temperature Q -frequency products of 1 014. These mechanical resonators can integrate quantum emitters or polariton condensates, opening exciting perspectives at the interface with nonlinear and quantum optics.

  18. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    DOE PAGES

    Munroe, Brian J.; Zhang, JieXi; Xu, Haoran; ...

    2016-03-29

    In this paper, we report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG) accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power ofmore » up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV=m at a breakdown probability of 1.19 × 10–1 per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90 MV=m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV=m at a breakdown probability of 1.09 × 10–1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.« less

  19. High Current Power Controller

    DTIC Science & Technology

    1981-04-01

    AFWAL-TR-81- 2016 U iui.N HIGH CURRENT Ŕ POWER CONTROLLER P. E. McCOLLUM Audwo ROCKWELL INTERNATIONAL AUTONETICS STRATEGIC SYSTEMS DIVISION 3370...personnel. During norm3l operation, HCP \\.s pose no hazard, bLt unde- certain operating conditions potential noaza-ds do exist. They are: (1) During

  20. High Power Cryogenic Targets

    SciTech Connect

    Gregory Smith

    2011-08-01

    The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.

  1. RF behavior of triple-frequency high power fusion gyrotron

    NASA Astrophysics Data System (ADS)

    Kumar, Nitin; Singh, Udaybir; Kumar, Anil; Sinha, A. K.

    2014-05-01

    The RF behavior of high power, triple frequency (170-, 127.5-, and 85 GHz) gyrotron for fusion application is presented in this paper. The operating mode selection is discussed in detail for each corresponding frequencies and TE34,10, TE25,8 and TE17,5 modes are selected as the operating mode for 170 GHz, 127.5 GHz and 85 GHz operation of the device, respectively. The interaction cavity geometry and beam parameters are finalized by the cold cavity analysis and beam-wave interaction simulations. Considering the beam parameters and the beam launching positions in cavity (beam radius), the design of Magnetically Tunable MIG (MT-MIG) is also presented. Results of MT-MIG confirm the beam launching with desired beam parameters at the beam radius corresponding to the selected operating modes for all three frequencies. The CVD diamond window is also designed for RF power transmission. The beam-wave interaction simulations confirm more than 1 MW power at all three frequencies (170-, 127.5-, and 85 GHz).

  2. High power arcjet

    NASA Technical Reports Server (NTRS)

    Goelz, T. M.; Auweter-Kurtz, M.; Kurtz, H. L.; Schrade, H. O.

    1991-01-01

    The activities of the High Power Arcjet Project (HIPARC) from August 1990 to January 1991 are discussed. In this period the HIPARC thruster was ignited for the first time. Power levels up to 140 kW with a mass flow rate of 300 mg/s hydrogen were reached. Specific impulse values of more than 1300 s were shown to be possible. Tests were performed with the baseline thruster version only, which has a 6 mm throat diameter and a conical nozzle with a 20 degree half angle. Measurement data summing up all tests carried out until now is included. All measuring methods are described, including a check on possible error sources.

  3. First results from the microwave air yield beam experiment (MAYBE): Measurement of GHz radiation for ultra-high energy cosmic ray detection

    SciTech Connect

    Williams, C.; Bohacova, M.; Bonifazi, C.; Cataldi, G.; Chemerisov, S.; De Mello Neto, J. R.T.; Facal San Luis, P.; Fox, B.; Gorham, P. W.; Hojvat, C.; Hollon, N.; Meyhandan, R.; Monasor, M.; D'Orfeuil, B. Rouille; Santos, E. M.; Pochez, J.; Privitera, P.; Spinka, H.; Verzi, V.; Zhou, J.

    2013-01-01

    We present measurements of microwave emission from an electron-beam induced air plasma performed at the 3 MeV electron Van de Graaff facility of the Argonne National Laboratory. Results include the emission spectrum between 1 and 15 GHz, the polarization of the microwave radiation and the scaling of the emitted power with respect to beam intensity. MAYBE measurements provide further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

  4. High power connection system

    SciTech Connect

    Schaefer, Christopher E.; Beer, Robert C.; McCall, Mark D.

    2000-01-01

    A high power connection system adapted for automotive environments which provides environmental and EMI shielding includes a female connector, a male connector, and a panel mount. The female connector includes a female connector base and a snap fitted female connector cover. The male connector includes a male connector base and a snap fitted male connector cover. The female connector base has at least one female power terminal cavity for seatably receiving a respective female power terminal. The male connector base has at least one male power terminal cavity for seatably receiving a respective male power terminal. The female connector is covered by a cover seal and a conductive shroud. A pair of lock arms protrude outward from the front end of the male connector base, pass through the panel mount and interface with a lever of a lever rotatably connected to the shroud to thereby mechanically assist mating of the male and female connectors. Safety terminals in the male and female connectors provide a last-to-connect-first-to-break connection with an HVIL circuit.

  5. On the averaging area for incident power density for human exposure limits at frequencies over 6 GHz

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yota; Hirata, Akimasa; Morimoto, Ryota; Aonuma, Shinta; Laakso, Ilkka; Jokela, Kari; Foster, Kenneth R.

    2017-04-01

    Incident power density is used as the dosimetric quantity to specify the restrictions on human exposure to electromagnetic fields at frequencies above 3 or 10 GHz in order to prevent excessive temperature elevation at the body surface. However, international standards and guidelines have different definitions for the size of the area over which the power density should be averaged. This study reports computational evaluation of the relationship between the size of the area over which incident power density is averaged and the local peak temperature elevation in a multi-layer model simulating a human body. Three wave sources are considered in the frequency range from 3 to 300 GHz: an ideal beam, a half-wave dipole antenna, and an antenna array. 1D analysis shows that averaging area of 20 mm  ×  20 mm is a good measure to correlate with the local peak temperature elevation when the field distribution is nearly uniform in that area. The averaging area is different from recommendations in the current international standards/guidelines, and not dependent on the frequency. For a non-uniform field distribution, such as a beam with small diameter, the incident power density should be compensated by multiplying a factor that can be derived from the ratio of the effective beam area to the averaging area. The findings in the present study suggest that the relationship obtained using the 1D approximation is applicable for deriving the relationship between the incident power density and the local temperature elevation.

  6. On the averaging area for incident power density for human exposure limits at frequencies over 6 GHz.

    PubMed

    Hashimoto, Yota; Hirata, Akimasa; Morimoto, Ryota; Aonuma, Shinta; Laakso, Ilkka; Jokela, Kari; Foster, Kenneth R

    2017-02-08

    Incident power density is used as the dosimetric quantity to specify the restrictions on human exposure to electromagnetic fields at frequencies above 3 or 10 GHz in order to prevent excessive temperature elevation at the body surface. However, international standards and guidelines have different definitions for the size of the area over which the power density should be averaged. This study reports computational evaluation of the relationship between the size of the area over which incident power density is averaged and the local peak temperature elevation in a multi-layer model simulating a human body. Three wave sources are considered in the frequency range from 3 to 300 GHz: an ideal beam, a half-wave dipole antenna, and an antenna array. 1D analysis shows that averaging area of 20 mm  ×  20 mm is a good measure to correlate with the local peak temperature elevation when the field distribution is nearly uniform in that area. The averaging area is different from recommendations in the current international standards/guidelines, and not dependent on the frequency. For a non-uniform field distribution, such as a beam with small diameter, the incident power density should be compensated by multiplying a factor that can be derived from the ratio of the effective beam area to the averaging area. The findings in the present study suggest that the relationship obtained using the 1D approximation is applicable for deriving the relationship between the incident power density and the local temperature elevation.

  7. Recent progress in high power ultrafast MIXSELs

    NASA Astrophysics Data System (ADS)

    Alfieri, C. G. E.; Waldburger, D.; Link, S. M.; Gini, E.; Golling, M.; Tilma, B. W.; Mangold, M.; Keller, U.

    2016-03-01

    The modelocked integrated external-cavity surface emitting laser (MIXSEL) is the most compact technology of ultrafast semiconductor disk laser, combining in the same epitaxial structure an active region and a saturable absorber for stable and self-starting passive modelocking in a linear straight cavity. Here we present the first MIXSEL structure able to produce sub-300-fs pulses at an average output power of 235 mW and 3.35 GHz pulse repetition rate, resulting in a record-high peak power of 240 W. At 10 GHz repetition rate the same MIXSEL generated 279-fs pulses with 310 mW of average output power. An optimized antireflection coating for dispersion minimization together with a reduced field enhancement inside the structure enabled the sensible improvement and the record performances of this novel MIXSEL. Furthermore, thanks to the development of suitable saturable absorbers with fast recovery dynamics and low saturation fluence, we demonstrate the first entirely MOVPE-grown MIXSEL.

  8. A portable high power microwave source with permanent magnets

    SciTech Connect

    Li, Wei; Zhang, Jun; Li, Zhi-qiang; Yang, Jian-Hua

    2016-06-15

    A high power microwave source with permanent magnets is proposed in this paper. The source has the length 330 mm, maximum diameter 350 mm, and total weight 50 kg, including 25 kg of permanent magnets. 1 GW of microwave power with Gaussian radiation pattern and 24% of microwave power generation efficiency in a pulse duration of 75 ns are obtained in the experiment. Operating frequency of the source is 2.32 GHz. Such a small size, light weight, and highly stable in operation source will be used in portable repetitive high power microwave generation systems.

  9. A smart repetitive-rate wideband high power microwave source

    SciTech Connect

    Li, Wei; Zhang, Jun; Qian, Bao-liang; Yang, Han-wu; Zhang, Zi-cheng

    2016-01-15

    A smart repetitive-rate wideband High Power Microwave (HPM) source based on the A6 Magnetron with Diffraction Output is described in this paper. The length of the HPM source is 30 cm and its weight is 35 kg. Computer simulations show that the source can produce microwave with central frequency of 1.91 GHz and bandwidth of about 11%. Experimental measurements show that the output microwave power from the source reaches in maximum 110 MW when the input electric power from the pulsed driver is ∼500 MW, which gives the power conversion efficiency 22%. Central frequency of the output HPM in the experiment is 1.94 GHz with the bandwidth ranging from 1.82 GHz to 2.02 GHz. The jitter of the output HPM power is lower than 3 dB when the source operates in the repetition mode with 50 Hz rate.

  10. High Power Spatial Combiners: Tile and Tray Approaches

    DTIC Science & Technology

    2001-01-01

    GHz with a 3-dB bandwidth of 1.8 GHz or 4.5%. The maximum saturated output power was 670 mW at 40 GHz with a peak power -added efficiency ... power added efficiency of 12%, which was the highest recorded output power of a spatial power combining amplifier at this frequency. The small-signal...5 dB of gain at 9.8 GHz with a 3-dB bandwidth of 400 MHz. The 3-dB compression power was 17.7 dBm with a power combining

  11. High Power Modulator.

    DTIC Science & Technology

    1986-08-01

    The bushing consists of three segments of alumina tubing with interspersed metal rings. All metallic surfaces ex- *posed to vacuum are stainless steel...high voltage transient only lasted for several hundred ns, no vacuum insulator breakdown was noted during the tests. 4.2 Acceptance tests at PSI The...ation at 1 pps. The oil insulated output pulse transformer has multiple secondary windings which can be used to provide heater power for a thermionic

  12. High Power Switching Transistor

    NASA Technical Reports Server (NTRS)

    Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

    1983-01-01

    Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

  13. High power arcjet

    NASA Technical Reports Server (NTRS)

    Auweter-Kurtz, M.; Glocker, B.; Goelz, T. M.; Habiger, H.; Kurtz, H. L.; Schrade, H. O.; Wegmann, T.

    1990-01-01

    The activities on the development of the high power arc jet HIPARC, the thrust balance, and plasma diagnostic probes are discussed. Modifications of the HIPARC design and a synopsis of the materials used are given. Further experimental results with the TT30 thruster in the 50 kW range are presented. Some first calibration measurements of the thrust balance are also included. Progress concerning the development of plasma diagnostic devices is documented.

  14. A novel 2.45 GHz/200 W Microwave Plasma Jet for High Temperature Applications above 3600 K

    NASA Astrophysics Data System (ADS)

    Schopp, C.; Nachtrodt, F.; Heuermann, H.; Scherer, U. W.; Mostacci, D.; Finger, T.; Tietsch, W.

    2012-12-01

    State of the art atmosphere plasma sources are operated with frequencies in kHz/MHz regions and all high power plasma jets make use of tungsten electrodes. A microwave plasma torch has been developed at FH Aachen for the application in various fields. The advantages over other plasma jet technologies are the high efficiency combined with a maintenance-free compact design and non-tungsten electrodes. In this paper the development of a 200 W torch is described. Argon is used as the primary plasma gas and a second gas can be applied for additional purposes. For the plasma generation a microwave at 2.45 GHz is sent through the torch. The special internal topology causes a high electric field that ignites the plasma at the tip and leads to the ionization of the passing Argon atoms which are emitted as a jet. By designing the copper electrode as a cannula it is possible to gain plasma temperatures higher than the electrode's melting point. The electric field simulations are made with Ansoft HFSS. Experiments were carried out to verify the simulations. The upcoming steps in the development will be the scale-up to higher power levels of several kW with a magnetron as power source.

  15. 6 GHz Microwave Power-Beaming Demonstration with 6-kV Rectenna and Ion-Breeze Thruster

    NASA Astrophysics Data System (ADS)

    Cummings, T.; Janssen, J.; Karnesky, J.; Laks, D.; Santillo, M.; Strause, B.; Myrabo, L. N.; Alden, A.; Bouliane, P.; Zhang, M.

    2004-03-01

    On 14 April 2003 at the Communications Research Center (CRC) in Ottawa, Ontario, a 5.85-GHz transmitter beamed 3-kW of microwave power to a remote rectifying antenna (i.e., rectenna) that delivered 6-kV to a special `Ion-Breeze' Engine (IBE). Three of CRC's 26.5-cm by 31-cm rectennas were connected in series to provide the ~6-kV output. RPI's low-voltage IBE thrusters performed well in a ``world's first'' power-beaming demonstration with rectennas and endoatmospheric ion-propulsion engines. The successful tests were a low-tech, proof-of-concept demonstration for the future full-sized MicroWave Lightcraft (MWLC) and its air breathing `loiter' propulsion mode. Additional IBE experiments investigated the feasibility of producing flight control forces on the MWLC. The objective was to torque the charged hull for `pitch' or `roll' maneuvers. The torquing demonstration was entirely successful.

  16. A high-efficiency 59- to 64-GHz TWT for intersatellite communications

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Ramins, Peter; Force, Dale A.; Limburg, Helen C.; Tammaru, Ivo

    1991-01-01

    The design of a 75-W, 59- to 64- GHz TWT with a predicted overall efficiency in excess of 40 percent is described. This intersatellite communications TWT, designated Model 961HA, employs a coupled-cavity slow-wave structure with a two-step velocity taper and an isotropic graphite multistage depressed collector (MDC). Because the RF efficiency of this TWT is less than 8 percent, an MDC design providing a very high collector efficiency was necessary to achieve the overall efficiency goal of 40 percent.

  17. Measurements of the temporal and spatial phase variations of a 33 GHz pulsed free electron laser amplifier and application to high gradient RF acceleration

    SciTech Connect

    Volfbeyn, P.; Bekefi, G.

    1995-12-31

    We report the results of temporal and spatial measurements of phase of a pulsed free electron laser amplifier (FEL) operating in combined wiggler and axial guide magnetic fields. The 33 GHz FEL is driven by a mildly relativistic electron beam (750 kV, 90-300 A, 30 ns) and generates 61 MW of radiation with a high power magnetron as the input source. The phase is measured by an interferometric technique from which frequency shifting is determined. The results are simulated with a computer code. Experimental studies on a CERN-CLIC 32.98 GHz 26-cell high gradient accelerating section (HGA) were carried out for input powers from 0.1 MW to 35 MW. The FEL served as the r.f. power source for the HGA. The maximum power in the transmitted pulse was measured to be 15 MW for an input pulse of 35 MW. The theoretically calculated shunt impedance of 116 M{Omega}/m predicts a field gradient of 65 MeV/m inside the HGA. For power levels >3MW the pulse transmitted through the HGA was observed to be shorter than the input pulse and pulse shortening became more serious with increasing power input. At the highest power levels the output pulse length (about 5 nsec) was about one quarter of the input pulse length. Various tests suggest that these undesirable effects occur in the input coupler to the HGA. Light and X-ray production inside the HGA have been observed.

  18. High power arcjet

    NASA Technical Reports Server (NTRS)

    Goelz, T. M.; Auweter-Kurtz, M.; Kurtz, H. L.; Schrade, H. O.

    1992-01-01

    In this period a new mass flow controller was brought into the gas supply system, so that the upper limit for the mass flow rate could be increased up to 500 mg/s with hydrogen. A maximum specific impulse of 1500 s could be achieved with the high powered arcjet (HIPARC) at an efficiency of slightly better than 20 percent. Different nozzle throat diameters had been tested. The 100 kilo-watt input power limit was reached with the 4 mm nozzle throat diameter at a mass flow rate of 400 mg/s. Tests were carried out with different cathode gaps and with three different cathodes. In addition measurements of pressure and gas temperature were taken in the feed line in order to determine the pressure drop in the propellant injectors.

  19. Waveguide Power Combiner Demonstration for Multiple High Power Millimeter Wave TWTAs

    NASA Technical Reports Server (NTRS)

    Wintucky, Edwin G.; Simons, Rainee N.; Lesny, Gary G.; Glass, Jeffrey L.

    2004-01-01

    NASA is presently developing nuclear reactor technologies, under Project Prometheus, which will provide spacecraft with greatly increased levels of sustained onboard power and thereby dramatically enhance the capability for future deep space exploration. The first mission planned for use of this high power technology is the Jupiter Icy Moons Orbiter (JIMO). In addition to electric propulsion and science, there will also be unprecedented onboard power available for deep space communications. A 32 GHz transmitter with 1 kW of RF output power is being considered to enable the required very high data transmission rates. One approach to achieving the 1 kW RF power, now being investigated at NASA GRC, is the possible power combining of a number of 100-1 50 W TWTs now under development. The work presented here is the results of a proof-of-concept demonstration of the power combining Ka-band waveguide circuit design and test procedure using two Ka- band TWTAs (Varian model VZA6902V3 and Logimetrics model A440/KA-1066), both of which were previously employed in data uplink evaluation terminals at 29.36 GHz for the NASA Advanced Communications Technology Satellite (ACTS) program. The characterization of the individual TWTAs and power combining demonstration were done over a 500 MHz bandwidth from 29.1 to 29.6 GHz to simulate the Deep Space Network (DSN) bandwidth of 3 1.8 to 32.3 GHz. Figures 1-3 show some of the power transfer and gain measurements of the TWTAs using a swept signal generator (Agilent 83640b) for the RF input. The input and output powers were corrected for circuit insertion losses due to the waveguide components. The RF saturated powers of both ACTS TWTAs were on the order of 120 W, which is comparable to the expected output powers of the 32 GHz TWTs. Additional results for the individual TWTAs will be presented (AM/AM, AM/PM conversion and gain compression), some of which were obtained from swept frequency and power measurements using a vector network

  20. High-power MUTC photodetectors for RF photonic links

    NASA Astrophysics Data System (ADS)

    Estrella, Steven; Johansson, Leif A.; Mashanovitch, Milan L.; Beling, Andreas

    2016-02-01

    High power photodiodes are needed for a range of applications. The high available power conversion efficiency makes these ideal for antenna remoting applications, including high power, low duty-cycle RF pulse generation. The compact footprint and fiber optic input allow densely packed RF aperture arrays with low cross-talk for phased high directionality emitters. Other applications include linear RF photonic links and other high dynamic range optical systems. Freedom Photonics has developed packaged modified uni-traveling carrier (MUTC) photodetectors for high-power applications. Both single and balanced photodetector pairs are mounted on a ceramic carrier, and packaged in a compact module optimized for high power operation. Representative results include greater than 100 mA photocurrent, >100m W generated RF power and >20 GHz bandwidth. In this paper, we evaluate the saturation and bandwidth of these single ended and balanced photodetectors for detector diameter in the 16 μm to 34 μm range. Packaged performance is compared to chip performance. Further new development towards the realization of <100GHz packaged photodetector modules with optimized high power performance is described. Finally, incorporation of these photodetector structures in novel photonic integrated circuits (PICs) for high optical power application areas is outlined.

  1. High voltage power supply

    NASA Astrophysics Data System (ADS)

    Ruitberg, A. P.; Young, K. M.

    1985-05-01

    A high voltage power supply is formed by three discrete circuits energized by a battery to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. In the first two circuits, the regulator stages are pulse width modulated and include adjustable ressistances for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance for varying the amplitude of a steady signal provided to a third oscillator stage. In the first circuit, the oscillator, formed by a constant current drive network and a tuned resonant network included a step up transformer, is coupled to a second step up transformer which, in turn, supplies an amplified sinusoidal signal to a parallel pair of complementary poled rectifying, voltage multiplier stages to generate the high output voltage.

  2. High voltage power supply

    NASA Technical Reports Server (NTRS)

    Ruitberg, A. P.; Young, K. M. (Inventor)

    1985-01-01

    A high voltage power supply is formed by three discrete circuits energized by a battery to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. In the first two circuits, the regulator stages are pulse width modulated and include adjustable ressistances for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance for varying the amplitude of a steady signal provided to a third oscillator stage. In the first circuit, the oscillator, formed by a constant current drive network and a tuned resonant network included a step up transformer, is coupled to a second step up transformer which, in turn, supplies an amplified sinusoidal signal to a parallel pair of complementary poled rectifying, voltage multiplier stages to generate the high output voltage.

  3. HIGH POWER PULSED OSCILLATOR

    DOEpatents

    Singer, S.; Neher, L.K.

    1957-09-24

    A high powered, radio frequency pulse oscillator is described for generating trains of oscillations at the instant an input direct voltage is impressed, or immediately upon application of a light pulse. In one embodiment, the pulse oscillator comprises a photo-multiplier tube with the cathode connected to the first dynode by means of a resistor, and adjacent dynodes are connected to each other through adjustable resistors. The ohmage of the resistors progressively increases from a very low value for resistors adjacent the cathode to a high value adjacent the plate, the last dynode. Oscillation occurs with this circuit when a high negative voltage pulse is applied to the cathode and the photo cathode is bombarded. Another embodiment adds capacitors at the resistor connection points of the above circuit to increase the duration of the oscillator train.

  4. LCLS-II high power RF system overview and progress

    SciTech Connect

    Yeremian, Anahid Dian

    2015-10-07

    A second X-ray free electron laser facility, LCLS-II, will be constructed at SLAC. LCLS-II is based on a 1.3 GHz, 4 GeV, continuous-wave (CW) superconducting linear accelerator, to be installed in the first kilometer of the SLAC tunnel. Multiple types of high power RF (HPRF) sources will be used to power different systems on LCLS-II. The main 1.3 GHz linac will be powered by 280 1.3 GHz, 3.8 kW solid state amplifier (SSA) sources. The normal conducting buncher in the injector will use four more SSAs identical to the linac SSAs but run at 2 kW. Two 185.7 MHz, 60 kW sources will power the photocathode dual-feed RF gun. A third harmonic linac section, included for linearizing the bunch energy spread before the first bunch compressor, will require sixteen 3.9 GHz sources at about 1 kW CW. A description and an update on all the HPRF sources of LCLS-II and their implementation is the subject of this paper.

  5. High power microwave generator

    DOEpatents

    Minich, Roger W.

    1988-01-01

    A device (10) for producing high-powered and coherent microwaves is described. The device comprises an evacuated, cylindrical, and hollow real cathode (20) that is driven to inwardly field emit relativistic electrons. The electrons pass through an internally disposed cylindrical and substantially electron-transparent cylindrical anode (24), proceed toward a cylindrical electron collector electrode (26), and form a cylindrical virtual cathode (32). Microwaves are produced by spatial and temporal oscillations of the cylindrical virtual cathode (32), and by electrons that reflex back and forth between the cylindrical virtual cathode (32) and the cylindrical real cathode (20).

  6. High Power Density Motors

    NASA Technical Reports Server (NTRS)

    Kascak, Daniel J.

    2004-01-01

    With the growing concerns of global warming, the need for pollution-free vehicles is ever increasing. Pollution-free flight is one of NASA's goals for the 21" Century. , One method of approaching that goal is hydrogen-fueled aircraft that use fuel cells or turbo- generators to develop electric power that can drive electric motors that turn the aircraft's propulsive fans or propellers. Hydrogen fuel would likely be carried as a liquid, stored in tanks at its boiling point of 20.5 K (-422.5 F). Conventional electric motors, however, are far too heavy (for a given horsepower) to use on aircraft. Fortunately the liquid hydrogen fuel can provide essentially free refrigeration that can be used to cool the windings of motors before the hydrogen is used for fuel. Either High Temperature Superconductors (HTS) or high purity metals such as copper or aluminum may be used in the motor windings. Superconductors have essentially zero electrical resistance to steady current. The electrical resistance of high purity aluminum or copper near liquid hydrogen temperature can be l/lOO* or less of the room temperature resistance. These conductors could provide higher motor efficiency than normal room-temperature motors achieve. But much more importantly, these conductors can carry ten to a hundred times more current than copper conductors do in normal motors operating at room temperature. This is a consequence of the low electrical resistance and of good heat transfer coefficients in boiling LH2. Thus the conductors can produce higher magnetic field strengths and consequently higher motor torque and power. Designs, analysis and actual cryogenic motor tests show that such cryogenic motors could produce three or more times as much power per unit weight as turbine engines can, whereas conventional motors produce only 1/5 as much power per weight as turbine engines. This summer work has been done with Litz wire to maximize the current density. The current is limited by the amount of heat it

  7. High Power Density Motors

    NASA Technical Reports Server (NTRS)

    Kascak, Daniel J.

    2004-01-01

    With the growing concerns of global warming, the need for pollution-free vehicles is ever increasing. Pollution-free flight is one of NASA's goals for the 21" Century. , One method of approaching that goal is hydrogen-fueled aircraft that use fuel cells or turbo- generators to develop electric power that can drive electric motors that turn the aircraft's propulsive fans or propellers. Hydrogen fuel would likely be carried as a liquid, stored in tanks at its boiling point of 20.5 K (-422.5 F). Conventional electric motors, however, are far too heavy (for a given horsepower) to use on aircraft. Fortunately the liquid hydrogen fuel can provide essentially free refrigeration that can be used to cool the windings of motors before the hydrogen is used for fuel. Either High Temperature Superconductors (HTS) or high purity metals such as copper or aluminum may be used in the motor windings. Superconductors have essentially zero electrical resistance to steady current. The electrical resistance of high purity aluminum or copper near liquid hydrogen temperature can be l/lOO* or less of the room temperature resistance. These conductors could provide higher motor efficiency than normal room-temperature motors achieve. But much more importantly, these conductors can carry ten to a hundred times more current than copper conductors do in normal motors operating at room temperature. This is a consequence of the low electrical resistance and of good heat transfer coefficients in boiling LH2. Thus the conductors can produce higher magnetic field strengths and consequently higher motor torque and power. Designs, analysis and actual cryogenic motor tests show that such cryogenic motors could produce three or more times as much power per unit weight as turbine engines can, whereas conventional motors produce only 1/5 as much power per weight as turbine engines. This summer work has been done with Litz wire to maximize the current density. The current is limited by the amount of heat it

  8. High Power Coax Window

    SciTech Connect

    Neubauer, M. L.; Dudas, A.; Sah, R.; Elliott, T. S.; Rimmer, R. A.; Stirbet, M. S.

    2010-05-23

    A su­per­con­duct­ing RF (SRF) power cou­pler ca­pa­ble of han­dling 500 kW CW RF power is re­quired for pre­sent and fu­ture stor­age rings and linacs. There are over 35 cou­pler de­signs for SRF cav­i­ties rang­ing in fre­quen­cy from 325 to 1500 MHz. Cou­pler win­dows vary from cylin­ders to cones to disks, and RF power cou­plers are lim­it­ed by the abil­i­ty of ce­ram­ic win­dows to with­stand the stress­es due to heat­ing and me­chan­i­cal flex­ure. We pro­pose a novel ro­bust co-ax­i­al SRF cou­pler de­sign which uses com­pressed win­dow tech­nol­o­gy. This tech­nol­o­gy will allow the use of high­ly ther­mal­ly con­duc­tive ma­te­ri­als for cryo­genic win­dows. Using com­pressed win­dow tech­niques on disk co-ax­i­al win­dows will make sig­nif­i­cant im­prove­ments in the power han­dling of SRF cou­plers. We pre­sent the bench test re­sults of two win­dow as­sem­blies back to back, as well as in­di­vid­u­al win­dow VSWR in EIA3.125 coax. A vac­u­um test as­sem­bly was made and the win­dows baked out at 155C. The pro­cess­es used to build win­dows is scal­able to larg­er di­am­e­ter coax and to high­er power lev­els.

  9. Enhanced highly charged ion production using a metal-dielectric liner in the KVI 14 GHz ECR ion source

    NASA Astrophysics Data System (ADS)

    Schachter, L.; Dobrescu, S.; Rodrigues, G.; Drentje, A. G.

    2002-02-01

    Forming on an aluminum surface a dielectric layer of alumina (aluminum oxide) in order to create a metal-dielectric (MD) structure increases the secondary-electron emission properties. The idea of using this material as a MD (Al-Al2O3) cylindrical liner inside an ECR ion source was previously tested in the 14 GHz ECRIS of IKF (Frankfurt/Main, Germany). The purpose of the present experiment was to observe the effect of such a MD liner on the high charge state operation of the KVI 14 GHz ECRIS, in particular in comparison to the technique of gas mixing. Measurements were made both with and without the MD liner, with pure argon and with an argon plus oxygen mixture. In the case of pure argon, the source with the MD liner is running remarkably stable. The high charge state ion beam currents are by far higher than those obtained in the situation where the source was operated with pure argon but without the MD liner. With MD liner, some low intensity oxygen peaks were clearly present in the spectra, implying that oxygen escaping or sputtered from the MD structure could give rise to an effect of "gas mixing." Therefore, the effect of mixing small amounts of oxygen into an argon plasma without the liner was studied in the same conditions of rf power and O3+ peak intensity. The conclusion was that the high charge state beam increase is not due to the oxygen gas mixing effect. The reason for the good performances of the source in the presence of the MD liner can be the increased density of cold electrons, but other effects could occur as well. This is subject of further studies.

  10. Theoretical and Experimental Study of Micro Air Vehicle Powered by RF Signal at 10 GHz

    DTIC Science & Technology

    2003-12-01

    inches. The rectifier antenna ( rectenna ) is a major component in a microwave power transmission process. A quality factor used for rectenna ...characterization is the conversion efficiency from microwave power to dc power. A key component in any rectenna design is the Schottky barrier diode which is...used to rectify the microwave energy to dc energy. A small rectenna array was manufactured using sixteen identical elements. Each element consisted of

  11. High power coaxial ubitron

    NASA Astrophysics Data System (ADS)

    Balkcum, Adam J.

    In the ubitron, also known as the free electron laser, high power coherent radiation is generated from the interaction of an undulating electron beam with an electromagnetic signal and a static periodic magnetic wiggler field. These devices have experimentally produced high power spanning the microwave to x-ray regimes. Potential applications range from microwave radar to the study of solid state material properties. In this dissertation, the efficient production of high power microwaves (HPM) is investigated for a ubitron employing a coaxial circuit and wiggler. Designs for the particular applications of an advanced high gradient linear accelerator driver and a directed energy source are presented. The coaxial ubitron is inherently suited for the production of HPM. It utilizes an annular electron beam to drive the low loss, RF breakdown resistant TE01 mode of a large coaxial circuit. The device's large cross-sectional area greatly reduces RF wall heat loading and the current density loading at the cathode required to produce the moderate energy (500 keV) but high current (1-10 kA) annular electron beam. Focusing and wiggling of the beam is achieved using coaxial annular periodic permanent magnet (PPM) stacks without a solenoidal guide magnetic field. This wiggler configuration is compact, efficient and can propagate the multi-kiloampere electron beams required for many HPM applications. The coaxial PPM ubitron in a traveling wave amplifier, cavity oscillator and klystron configuration is investigated using linear theory and simulation codes. A condition for the dc electron beam stability in the coaxial wiggler is derived and verified using the 2-1/2 dimensional particle-in-cell code, MAGIC. New linear theories for the cavity start-oscillation current and gain in a klystron are derived. A self-consistent nonlinear theory for the ubitron-TWT and a new nonlinear theory for the ubitron oscillator are presented. These form the basis for simulation codes which, along

  12. High-Temperature RF Probe Station For Device Characterization Through 500 deg C and 50 GHz

    NASA Technical Reports Server (NTRS)

    Schwartz, Zachary D.; Downey, Alan N.; Alterovitz, Samuel A.; Ponchak, George E.; Williams, W. D. (Technical Monitor)

    2003-01-01

    A high-temperature measurement system capable of performing on-wafer microwave testing of semiconductor devices has been developed. This high temperature probe station can characterize active and passive devices and circuits at temperatures ranging from room temperature to above 500 C. The heating system uses a ceramic heater mounted on an insulating block of NASA shuttle tile material. The temperature is adjusted by a graphical computer interface and is controlled by the software-based feedback loop. The system is used with a Hewlett-Packard 8510C Network Analyzer to measure scattering parameters over a frequency range of 1 to 50 GHz. The microwave probes, cables, and inspection microscope are all shielded to protect from heat damage. The high temperature probe station has been successfully used to characterize gold transmission lines on silicon carbide at temperatures up to 540 C.

  13. High capacity digital radio system family for the 18 GHz band

    NASA Astrophysics Data System (ADS)

    Otremba, K.; Steinkamp, J.; Thaler, H.-J.; Vogel, K.

    A highly modular family of large-capacity radio relay systems designed for the channel allocation plans of the 18-GHz band is presented. It makes use of 16-QAM and cochannel operation and provides high spectrum efficiency up to 6.8 b/s/Hz. Indirect modulation with spectrum shaping at IF based on a highly sophisticated SAW filter technology is combined with a multiple IF carrier approach, so that a transmission capacity of up to 1.12 Gb/s per RF and a maximum band capacity of 4.5 Gb/s is achieved. The intended use of this family is the extension of optical filter routes and application in densely meshed trunk and regional networks, especially where frequency coordination problems must be solved.

  14. High resolution observations of compact H II regions at 230 GHz

    NASA Technical Reports Server (NTRS)

    Wink, JOERN-E.; Mezger, P. G.; Zylka, R.

    1989-01-01

    Based on the idea that star formation goes on progressively in molecular clouds, a search was conducted for protostars by mapping compact H II regions at a frequency of 250 GHz. The IRAM 30 m radio telescope was used with a (3)He cooled bolometer. Twenty compact H II regions usually obtaining twice the expected free-free flux density, positionally coincident with the H II region, were observed. Even fine structure within the H II regions can be traced in the maps as in the case of G75.84+0.40 near ON-2. The high degree of coincidence between the 250 and 5 GHz map of Harris shows that the excess flux density observed must come from dust mixed with the ionized gas. Part of the dust must however be accumulated in the outer part of the H II region, since in some cases the contours are shifted outwards relative to the radio maps. This is consistent with the fact that in those cases where enough information is available to make a model fit, temperatures were derived of 80 + or - 30 K.

  15. A high dynamic range power sensor based on GaAs MMIC process and MEMS technology

    NASA Astrophysics Data System (ADS)

    Yi, Zhenxiang; Liao, Xiaoping

    2016-01-01

    This paper reports a high dynamic range power sensor based on GaAs process and MEMS technology. The proposed sensor consisted of the terminating-type sensor and the coupling-type sensor. The former measures low power while the latter is for high power detection. This device is designed and fabricated by GaAs MMIC process. In order to optimize microwave performance, impedance compensating technology by increasing the slot width of the CPW transmission line is developed. Related calculation and simulation are also presented in this paper. The microwave performance test reveals that the return loss is close to -28 dB@8 GHz, -27 dB@10 GHz and -26 dB@12 GHz, respectively. The microwave power response experiment is investigated from 1 mW to 150 mW. For the incident power less than 100 mW, the terminating-type sensor operates and the measured sensitivity is about 0.095 mV/mW@8 GHz, 0.088 mV/mW@10 GHz and 0.084 mV/mW@12 GHz, respectively. Related lumped equivalent circuit models of the loaded resistors are developed to explain the loss induced by the frequency of the signal. For the incident power with the improved dynamic range from 100 mW to 150 mW, the coupling-type sensor is adopted and the measured sensitivity is about 9.2 μV/mW@8 GHz, 8.6 μV/mW@8 GHz and 9.0 μV/mW@12 GHz, respectively.

  16. High Power Local Oscillator Sources for 1-2 THz

    NASA Technical Reports Server (NTRS)

    Mehdi, Imran; Thomas, Bertrand; Lin, Robert; Maestrini, Alain; Ward, John; Schlecht, Erich; Gill, John; Lee, Choonsup; Chattopadhyay, Goutam; Maiwald, Frank

    2010-01-01

    Recent results from the Heterodyne Instrument for Far-Infrared (HIFI) on the Herschel Space Telescope have confirmed the usefulness of high resolution spectroscopic data for a better understanding of our Universe. This paper will explore the current status of tunable local oscillator sources beyond HIFI and provide demonstration of how power combining of GaAs Schottky diodes can be used to increase both power and upper operating frequency for heterodyne receivers. Availability of power levels greater than 1 watt in the W-band now makes it possible to design a 1900 GHz source with more than 100 microwatts of expected output power.

  17. Progress in high-temperature oven development for 28 GHz electron cyclotron resonance ion source

    SciTech Connect

    Ohnishi, J. Higurashi, Y.; Nakagawa, T.

    2016-02-15

    We have been developing a high-temperature oven using UO{sub 2} in the 28 GHz superconducting electron cyclotron resonance ion source at RIKEN since 2013. A total of eleven on-line tests were performed. The longest operation time in a single test was 411 h, and the consumption rate of UO{sub 2} was approximately 2.4 mg/h. In these tests, we experienced several problems: the ejection hole of a crucible was blocked with UO{sub 2} and a crucible was damaged because of the reduction of tungsten strength at high temperature. In order to solve these problems, improvements to the crucible shape were made by simulations using ANSYS.

  18. 12-GHz thin-film transistors on transferrable silicon nanomembranes for high-performance flexible electronics.

    PubMed

    Sun, Lei; Qin, Guoxuan; Seo, Jung-Hun; Celler, George K; Zhou, Weidong; Ma, Zhenqiang

    2010-11-22

    Multigigahertz flexible electronics are attractive and have broad applications. A gate-after-source/drain fabrication process using preselectively doped single-crystal silicon nanomembranes (SiNM) is an effective approach to realizing high device speed. However, further downscaling this approach has become difficult in lithography alignment. In this full paper, a local alignment scheme in combination with more accurate SiNM transfer measures for minimizing alignment errors is reported. By realizing 1 μm channel alignment for the SiNMs on a soft plastic substrate, thin-film transistors with a record speed of 12 GHz maximum oscillation frequency are demonstrated. These results indicate the great potential of properly processed SiNMs for high-performance flexible electronics.

  19. High power beam analysis

    NASA Astrophysics Data System (ADS)

    Aharon, Oren

    2014-02-01

    In various modern scientific and industrial laser applications, beam-shaping optics manipulates the laser spot size and its intensity distribution. However the designed laser spot frequently deviates from the design goal due to real life imperfections and effects, such as: input laser distortions, optical distortion, heating, overall instabilities, and non-linear effects. Lasers provide the ability to accurately deliver large amounts of energy to a target area with very high accuracy. Thus monitoring beam size power and beam location is of high importance for high quality results and repeatability. Depending on the combination of wavelength, beam size and pulse duration , laser energy is absorbed by the material surface, yielding into processes such as cutting, welding, surface treatment, brazing and many other applications. This article will cover the aspect of laser beam measurements, especially at the focal point where it matters the most. A brief introduction to the material processing interactions will be covered, followed by fundamentals of laser beam propagation, novel measurement techniques, actual measurement and brief conclusions.

  20. Spectrum efficiency gains resulting from the implementation of adaptive transmit power control in fixed terrestrial links at 38 GHz

    NASA Astrophysics Data System (ADS)

    Callaghan, S. A.; Inglis, I.; Hansell, P.

    2009-06-01

    Adaptive transmit power control (ATPC) can be used to improve the spectrum efficiency of terrestrial point-to-point fixed links by limiting the transmit power to that required to maintain a constant bit error rate regardless of the propagation conditions. This results in a reduced transmit power being used during clear-sky conditions, lowering the interference resulting from the ATPC link. This improves the frequency reuse factor associated with a given band and geographic area, providing a spectrum efficiency gain. The project described in this paper found that implementing ATPC in the 38 GHz terrestrial fixed links band gives significant improvements in spectrum efficiency as measured by the increase in the number of links assigned to channel 1 (from ˜50% to ˜70%) and the decrease in the maximum bandwidth used (from ˜300 MHz to ˜180 MHz). However, a model plan exposed to an exceptionally intense frontal rain event showed a number of additional outages caused by ATPC, amounting to approximately 12% of the number of outages caused directly by rain. In comparison, when exposed to an annualized simulated rain database the number of extra outages in this case falls to 2.6%.

  1. The 20 GHz circularly polarized, high temperature superconducting microstrip antenna array

    NASA Technical Reports Server (NTRS)

    Morrow, Jarrett D.; Williams, Jeffery T.; Long, Stuart A.; Wolfe, John C.

    1994-01-01

    The primary goal was to design and characterize a four-element, 20 GHz, circularly polarized microstrip patch antenna fabricated from YBa2Cu3O(x) superconductor. The purpose is to support a high temperature superconductivity flight communications experiment between the space shuttle orbiter and the ACTS satellite. This study is intended to provide information into the design, construction, and feasibility of a circularly polarized superconducting 20 GHz downlink or cross-link antenna. We have demonstrated that significant gain improvements can be realized by using superconducting materials for large corporate fed array antennas. In addition, we have shown that when constructed from superconducting materials, the efficiency, and therefore the gain, of microstrip patches increases if the substrate is not so thick that the dominant loss mechanism for the patch is radiation into the surface waves of the conductor-backed substrate. We have considered two design configurations for a superconducting 20 GHz four-element circularly polarized microstrip antenna array. The first is the Huang array that uses properly oriented and phased linearly polarized microstrip patch elements to realize a circularly polarized pattern. The second is a gap-coupled array of circularly polarized elements. In this study we determined that although the Huang array operates well on low dielectric constant substrates, its performance becomes extremely sensitive to mismatches, interelement coupling, and design imperfections for substrates with high dielectric constants. For the gap-coupled microstrip array, we were able to fabricate and test circularly polarized elements and four-element arrays on LaAlO3 using sputtered copper films. These antennas were found to perform well, with relatively good circular polarization. In addition, we realized a four-element YBa2Cu3O(x) array of the same design and measured its pattern and gain relative to a room temperature copper array. The patterns were

  2. High Peak Power Ka-Band Gyrotron Oscillator Experiment.

    DTIC Science & Technology

    1987-09-21

    has also demonstrated frequency tuning over the range 28 to 49 GHz by operating in a family of TE.’ modes, with the azimuthal index m ranging from 4 to...10, by Varia- tion of the guide magnetic field. Operation is in general agrement with the predictions of theory. 1% 20. DISTRIBUTION /AVAILABIUTY OF...proved to be highly efficient, exceptionally high average power millimeter-wave sources.1 Operating at moderate currents and voltages (typically, S50

  3. Low power considerations and design for CMOS VCOs applied for direct conversion receivers at 5GHz

    NASA Astrophysics Data System (ADS)

    Adin, Iñigo; Quemada, Carlos; Solar, Hector; Sedano, Beatriz; Gutierrez, Iñigo

    2007-05-01

    Low power design often requires direct conversion architectures, such as low-IF or zero-IF. Any of these two possibilities needs a low power, low phase noise voltage control oscillator (VCO) in the frequency synthesizer. This work is focused on low power considerations applied to the practical modern conception of this device. Fulfilling the standard specifications (output power, phase noise, frequency range) should be completed with this deeper step. A conscious design leads moreover to an improvement in the results obtained by the classical considerations. The increase of the quality factor of the passive elements is one of the key points, followed by an accurate design of the architecture scheme. Furthermore, lower current consumption provides higher oscillation frequencies and facilitates higher frequency ranges, which follow the trends of modern wireless and wideband communication standards. In order to validate the aforementioned assumptions, a CMOS VCO has been implemented in UMC 0.18μm 1P6M technology, with power consumption down to 3.4mW.

  4. Suppression of spurious mode oscillation in mega-watt 77-GHz gyrotron as a high quality probe beam source for the collective Thomson scattering in LHD

    SciTech Connect

    Ogasawara, S.; Kubo, S.; Nishiura, M.; Tanaka, K.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Ito, S.; Takita, Y.; Kobayashi, S.; Mizuno, Y.; Okada, K.; Tatematsu, Y.; Saito, T.; Minami, R.; Kariya, T.; Imai, T.

    2012-10-15

    Collective Thomson scattering (CTS) diagnostic requires a strong probing beam to diagnose a bulk and fast ion distribution function in fusion plasmas. A mega-watt gyrotron for electron cyclotron resonance heating is used as a probing beam in the large helical device. Spurious mode oscillations are often observed during the turning on/off phase of the modulation. The frequency spectra of the 77-GHz gyrotron output power have been measured, and then one of the spurious modes, which interferes with the CTS receiver system, is identified as the TE{sub 17,6} mode at the frequency of 74.7 GHz. The mode competition calculation indicates that the increase of the magnetic field strength at the gyrotron resonator can avoid such a spurious mode and excite only the main TE{sub 18,6} mode. The spurious radiation at the 74.7 GHz is experimentally demonstrated to be suppressed in the stronger magnetic field than that optimized for the high-power operation.

  5. High-gain 35-GHz free-electron laser-amplifier experiment

    NASA Astrophysics Data System (ADS)

    Gold, S. H.; Hardesty, D. L.; Kinkead, A. K.; Barnett, L. R.; Granatstein, V. L.

    1984-04-01

    The efficient operation of a high-gain collective free-electron-laser (FEL) amplifier is demonstrated experimentally. The device investigated comprises a magnetron (20 kW, 500-nsec pulses at 35.02 GHz), a 20-dB-directivity input coupler for TE(11)-mode vertical polarization, the FEL interaction region (3-cm-period 63-cm-uniform-field-length wiggler field adjustable up to 4 kG, axial field up to 20 kG, and 10.08-mm drift tube), the VEBA pulse line accelerator (producing a 6-mm-diameter 900-keV 600-A 60-nsec FWHM relativistic electron beam), and a measurement setup. Linear growth at 1.2 dB/cm is reported, with total gain 50 dB, coherent emission 17 MW, and efficiency greater than 3 percent.

  6. High power, high frequency component test facility

    NASA Technical Reports Server (NTRS)

    Roth, Mary Ellen; Krawczonek, Walter

    1990-01-01

    The NASA Lewis Research Center has available a high frequency, high power laboratory facility for testing various components of aerospace and/or terrestrial power systems. This facility is described here. All of its capabilities and potential applications are detailed.

  7. THE ATACAMA COSMOLOGY TELESCOPE: A MEASUREMENT OF THE 600 < l < 8000 COSMIC MICROWAVE BACKGROUND POWER SPECTRUM AT 148 GHz

    SciTech Connect

    Fowler, J. W.; Appel, J. W.; Das, S.; Dunkley, J.; Essinger-Hileman, T.; Fisher, R. P.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Barrientos, L. F.; Duenner, R.; Amiri, M.; Battistelli, E. S.; Burger, B.; Bond, J. R.; Brown, B.; Chervenak, J.; Doriese, W. B.

    2010-10-20

    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1.'4 angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg{sup 2} of the southern sky, in a 4.{sup 0}2 wide strip centered on declination 53{sup 0} south. The CMB at arcminute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy clusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 < l < 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 < l < 1150. The power beyond the Silk damping tail of the CMB (l {approx} 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to {sigma}{sub 8} = 0.8. We constrain the model's amplitude A{sub SZ} < 1.63 (95% CL). If interpreted as a measurement of {sigma}{sub 8}, this implies {sigma}{sup SZ}{sub 8} < 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a six-parameter {Lambda}CDM model plus point sources and the SZ effect is consistent with these results.

  8. High sensitivity broadband 360GHz passive receiver for TeraSCREEN

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Oldfield, Matthew; Maestrojuán, Itziar; Platt, Duncan; Brewster, Nick; Viegas, Colin; Alderman, Byron; Ellison, Brian N.

    2016-05-01

    TeraSCREEN is an EU FP7 Security project aimed at developing a combined active, with frequency channel centered at 360 GHz, and passive, with frequency channels centered at 94, 220 and 360 GHz, imaging system for border controls in airport and commercial ferry ports. The system will include automatic threat detection and classification and has been designed with a strong focus on the ethical, legal and practical aspects of operating in these environments and with the potential threats in mind. Furthermore, both the passive and active systems are based on array receivers with the active system consisting of a 16 element MIMO FMCW radar centered at 360 GHz with a bandwidth of 30 GHz utilizing a custom made direct digital synthesizer. The 16 element passive receiver system at 360 GHz uses commercial Gunn diode oscillators at 90 GHz followed by custom made 90 to 180 GHz frequency doublers supplying the local oscillator for 360 GHz sub-harmonic mixers. This paper describes the development of the passive antenna module, local oscillator chain, frequency mixers and detectors used in the passive receiver array of this system. The complete passive receiver chain is characterized in this paper.

  9. High-speed and high-output-power unitraveling-carrier photodiodes

    NASA Astrophysics Data System (ADS)

    Ito, Hiroshi; Nagatsuma, Tadao

    2003-08-01

    The uni-traveling-carrier photodiode (UTC-PD) is a novel photodiode that utilizes only electrons as the active carriers. This unique feature is the key to achieving excellent high-speed and high-output characteristics simultaneously. A record 3-dB bandwidth of 310 GHz and a millimeter-wave output power of over 20 mW at 100 GHz have already been achieved. The superior capability of the UTC-PD for generating very-large high-bit-rate electrical signals as well as a very-high output power in millimeter/sub-millimeter ranges can innovate various systems, such as broadband optical communications systems, wireless communications systems, and high-frequency measurement systems. Achievements include photoreceivers of up to 80 Gbit/s, DEMUX operations using an integrated optical gate of up to 320 Gbit/s, and a 10-Gbit/s millimeter-wave wireless link at 120 GHz. Also achieved has been high-power millimeter generation of 17 mW at 120 GHz with a waveguide-output UTC-PD module, considered for use in the photonic-local system of radio telescopes.

  10. 93-133 GHz Band InP High-Electron-Mobility Transistor Amplifier with Gain-Enhanced Topology

    NASA Astrophysics Data System (ADS)

    Sato, Masaru; Shiba, Shoichi; Matsumura, Hiroshi; Takahashi, Tsuyoshi; Nakasha, Yasuhiro; Suzuki, Toshihide; Hara, Naoki

    2013-04-01

    In this study, we developed a new type of high-frequency amplifier topology using 75-nm-gate-length InP-based high-electron-mobility transistors (InP HEMTs). To enhance the gain for a wide frequency range, a common-source common-gate hybrid amplifier topology was proposed. A transformer-based balun placed at the input of the amplifier generates differential signals, which are fed to the gate and source terminals of the transistor. The amplified signal is outputted at the drain node. The simulation results show that the hybrid topology exhibits a higher gain from 90 to 140 GHz than that of the conventional common-source or common-gate amplifier. The two-stage amplifier fabricated using the topology exhibits a small signal gain of 12 dB and a 3-dB bandwidth of 40 GHz (93-133 GHz), which is the largest bandwidth and the second highest gain reported among those of published 120-GHz-band amplifiers. In addition, the measured noise figure was 5 dB from 90 to 100 GHz.

  11. High figure-of-merit compact phase shifters based on liquid crystal material for 1-10 GHz applications

    NASA Astrophysics Data System (ADS)

    Cai, Longzhu; Xu, Huan; Li, Jinfeng; Chu, Daping

    2017-01-01

    A liquid crystal (LC) based tunable microstrip line (ML) phase shifter featuring high performance is presented. The experimental results show an electrically tunable differential phase up to 360° at 10 GHz with an overall insertion loss <8.5 dB. The device possesses a high figure-of-merit (FoM) of 64°/dB at 9.8 GHz and 60°/dB between 7-10 GHz. This is achieved by simultaneously considering both of the LC tuned phase and overall loss in the design. The proposed device utilizes the inverted meander ML technology to minimize its size. Taking into account the real fabrication procedure, a novel impedance matching structure is applied, and the measured return loss is considerably improved. The FoM and phase tuning property of the fabricated device as optimized are compared with the state-of-art results published recently and show better performance for both of them.

  12. Solar powerful short-term flare in NOAA12628 at 3-4 GHz on 25 Jan 2017, 10:16:43 UT

    NASA Astrophysics Data System (ADS)

    Bogod, V. M.; Kaltman, T. I.; Pervakov, A. A.; Sotnikova, Yu. V.; Trushkin, S. A.

    2017-01-01

    The unusual solar powerful short-term flare in the active region NOAA12628 was detected at the frequencies: 3.094, 3.281, 3.469, and 3.844 GHz on 25 Jan 2017 (10:16:43 UT) in regular solar observations with the RATAN-600 radio telescope.

  13. A Sampled Grating DBR Laser Monolithically Integrated by Using SOAs with 22 mW Output Power and 51 ITU 100 GHz Channels over 43 nm

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Ye, Nan; Zhou, Dai-Bing; Wang, Bao-Jun; Pan, Jiao-Qing; Zhao, Ling-Juan; Wang, Wei

    2011-02-01

    A sampled grating distributed Bragg reflector (SG-DBR) laser monolithically integrated with semiconductor optical amplifiers (SOAs), which has a tuning range over 43 nm from 1514.05 nm to 1557.4 nm covering 49 continuous and totally 51 ITU 100 GHz standard channels and an output power more than 22 mW for all output wavelengths, is successfully demonstrated.

  14. 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.

  15. Measurements of the Low Frequency Gain Fluctuations of a 30 GHz High-Electron-Mobility-Transistor Cryogenic Amplifier

    NASA Technical Reports Server (NTRS)

    Jarosik, Norman

    1994-01-01

    Low frequency gain fluctuations of a 30 GHz cryogenic HEMT amplifier have been measured with the input of the amplifier connected to a 15 K load. Effects of fluctuations of other components of the test set-up were eliminated by use of a power-power correlation technique. Strong correlation between output power fluctuations of the amplifier and drain current fluctuations of the transistors comprising the amplifier are observed. The existence of these correlations introduces the possibility of regressing some of the excess noise from the HEMT amplifier's output using the measured drain currents.

  16. High-efficiency 20 GHz traveling wave tube development for space communications

    NASA Technical Reports Server (NTRS)

    Aldana, S. L.; Tamashiro, R. N.

    1991-01-01

    A 75 watt CW high efficiency helix TWT operating at 20 GHz was developed for satellite communication systems. The purpose was to extend the performance capabilities of helix TWTs by using recent technology developments. The TWT described is a unique design because high overall efficiency is obtained with a low perveance beam. In the past, low perveance designs resulted in low beam efficiencies. However, due to recent breakthoughs in diamond rod technology and in collector electrode materials, high efficiencies can now be achieved with low perveance beams. The advantage of a low perveance beam is a reduction in space charge within the beam which translates to more efficient collector operation. In addition, this design incorporates textured graphite electrodes which further enhance collector operation by suppressing backstreaming secondaries. The diamond supported helix circuit features low RF losses, high interaction impedance, good thermal handling capability and has been designed to compensate for the low perveance beam. One more discussed tube feature is the use of a velocity taper in the output helix that achieves low signal distortion while maintaining high efficiency.

  17. Ku-band high efficiency GaAs MMIC power amplifiers

    NASA Technical Reports Server (NTRS)

    Tserng, H. Q.; Witkowski, L. C.; Wurtele, M.; Saunier, Paul

    1988-01-01

    The development of Ku-band high efficiency GaAs MMIC power amplifiers is examined. Three amplifier modules operating over the 13 to 15 GHz frequency range are to be developed. The first MMIC is a 1 W variable power amplifier (VPA) with 35 percent efficiency. On-chip digital gain control is to be provided. The second MMIC is a medium power amplifier (MPA) with an output power goal of 1 W and 40 percent power-added efficiency. The third MMIC is a high power amplifier (HPA) with 4 W output power goal and 40 percent power-added efficiency. An output power of 0.36 W/mm with 49 percent efficiency was obtained on an ion implanted single gate MESFET at 15 GHz. On a dual gate MESFET, an output power of 0.42 W/mm with 27 percent efficiency was obtained. A mask set was designed that includes single stage, two stage, and three stage single gate amplifiers. A single stage 600 micron amplifier produced 0.4 W/mm output power with 40 percent efficiency at 14 GHz. A four stage dual gate amplifier generated 500 mW of output power with 20 dB gain at 17 GHz. A four-bit digital-to-analog converter was designed and fabricated which has an output swing of -3 V to +/- 1 V.

  18. Human speech articulator measurements using low power, 2GHz Homodyne sensors

    SciTech Connect

    Barnes, T; Burnett, G C; Holzrichter, J F

    1999-06-29

    Very low power, short-range microwave ''radar-like'' sensors can measure the motions and vibrations of internal human speech articulators as speech is produced. In these animate (and also in inanimate acoustic systems) microwave sensors can measure vibration information associated with excitation sources and other interfaces. These data, together with the corresponding acoustic data, enable the calculation of system transfer functions. This information appears to be useful for a surprisingly wide range of applications such as speech coding and recognition, speaker or object identification, speech and musical instrument synthesis, noise cancellation, and other applications.

  19. High-Efficiency Power Module

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

    2015-01-01

    One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

  20. High-Efficiency Power Module

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N (Inventor); Wintucky, Edwin G (Inventor)

    2013-01-01

    One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

  1. Multivoltage high power electrical power system

    NASA Astrophysics Data System (ADS)

    Hyvarinen, W. E.

    Applications are being identified where the optimum aircraft electrical system may not be the conventional 400 Hz approach. The requirements for a multivoltage high power airborne electrical system are presented. The methodology used to define and evaluate operating parameters, system configuration and control philosophy are presented. The approach recommended for this application is described.

  2. The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectrum at 148 AND 218 GHz from the 2008 Southern Survey

    NASA Technical Reports Server (NTRS)

    Das, Sudeep; Marriage, Tobias A.; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John W.; Barrientos, L. Felipe; Battistelli, Elia A.; Bond, J. Richard; Brown, Ben; Burger, Bryce; Chervenak, Jay; Devlin, Mark J.; Dicker, Simon R.; Doriese, W. Bertrand; Dunkley, Joanna; Duenner, Rolando; Essinger-Hileman, Thomas; Fisher, Ryan P.; Fowler, Joseph W.; Hajian, Amir; Halpern, Mark; Hasselfield, Matthew; Hernandez-Monteagudo, Carlos; Wollack, Ed

    2010-01-01

    We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results dearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the ACDM cosmological model. At l > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < l < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8(sigma) level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.

  3. High-Power Microwave Switch Employing Electron Beam Triggering

    SciTech Connect

    Hirshfield, Jay L

    2012-09-19

    A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - 165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.

  4. VizieR Online Data Catalog: ACT high significance 148 and 218GHz sources (Marsden+, 2014)

    NASA Astrophysics Data System (ADS)

    Marsden, D.; Gralla, M.; Marriage, T. A.; Switzer, E. R.; Partridge, B.; Massardi, M.; Morales, G.; Addison, G.; Bond, J. R.; Crichton, D.; Das, S.; Devlin, M.; Dunner, R.; Hajian, A.; Hilton, M.; Hincks, A.; Hughes, J. P.; Irwin, K.; Kosowsky, A.; Menanteau, F.; Moodley, K.; Niemack, M.; Page, L.; Reese, E. D.; Schmitt, B.; Sehgal, N.; Sievers, J.; Staggs, S.; Swetz, D.; Thornton, R.; Wollack, E.

    2014-11-01

    The ACT experiment (Swetz et al., 2011ApJS..194...41S) is situated on the slopes of Cerro Toco in the Atacama Desert of Chile at an elevation of 5190m. ACT's latitude gives access to both the northern and southern celestial hemispheres. Observations occurred simultaneously in three frequency bands, at 148GHz (2.0mm), 218GHz (1.4mm) and 277GHz (1.1mm) with angular resolutions of roughly 1.4 , 1.0 and 0.9-arcmin, respectively. (1 data file).

  5. Blood-brain barrier permeation in the rat during exposure to low-power 1. 7-GHz microwave radiation

    SciTech Connect

    Ward, T.R.; Ali, J.S.

    1985-01-01

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of (/sup 14/C) sucrose and (/sup 3/H) inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals.

  6. Blood-brain barrier permeation in the rat during exposure to low-power 1. 7-GHz microwave radiation

    SciTech Connect

    Ward, T.R.; Ali, J.S.

    1985-01-01

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous wave (CW) and pulsed microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of /sup 14/C-sucrose and /sup 3/H-insulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7 GHz CW and pulsed (0.5-us pulse width, 1000 pps) microwave radiation. Following exposure, the brain was perfused and sectioned into nine regions and the radioactivity in each region was counted. During identical exposure conditions, temperatures were measured in eight of the brain regions using a nonperturbing thermistor probe. No change in uptake of either tracer was found in any region as compared to sham-exposed animals.

  7. Distribution of high-stability 10 GHz local oscillator over 100 km optical fiber with accurate phase-correction system.

    PubMed

    Wang, Siwei; Sun, Dongning; Dong, Yi; Xie, Weilin; Shi, Hongxiao; Yi, Lilin; Hu, Weisheng

    2014-02-15

    We have developed a radio-frequency local oscillator remote distribution system, which transfers a phase-stabilized 10.03 GHz signal over 100 km optical fiber. The phase noise of the remote signal caused by temperature and mechanical stress variations on the fiber is compensated by a high-precision phase-correction system, which is achieved using a single sideband modulator to transfer the phase correction from intermediate frequency to radio frequency, thus enabling accurate phase control of the 10 GHz signal. The residual phase noise of the remote 10.03 GHz signal is measured to be -70  dBc/Hz at 1 Hz offset, and long-term stability of less than 1×10⁻¹⁶ at 10,000 s averaging time is achieved. Phase error is less than ±0.03π.

  8. Large-Area Monolayer MoS2 for Flexible Low-Power RF Nanoelectronics in the GHz Regime.

    PubMed

    Chang, Hsiao-Yu; Yogeesh, Maruthi Nagavalli; Ghosh, Rudresh; Rai, Amritesh; Sanne, Atresh; Yang, Shixuan; Lu, Nanshu; Banerjee, Sanjay Kumar; Akinwande, Deji

    2016-03-02

    Flexible synthesized MoS2 transistors are advanced to perform at GHz speeds. An intrinsic cutoff frequency of 5.6 GHz is achieved and analog circuits are realized. Devices are mechanically robust for 10,000 bending cycles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Devices and materials for THz spectroscopy: GHz CMOS circuits, periodic hole-arrays and high-frequency dielectric materials

    NASA Astrophysics Data System (ADS)

    Arenas, Daniel J.

    This dissertation is composed of three main projects, linked together by the THz region of the electromagnetic spectrum. In the first project, we detected the radiation from a silicon CMOS circuit, using a fourier transform interferometer. At the time of measurement, this 410 GHz circuit had the highest operating frequency for silicon integrated technology. The measured radiated power from the 410 GHz circuits was in the order of 0.01 muW. This circuit had radiated intensities comparable to those of commercially available black-body sources in the 400 GHz region. The high power and high emission per source area suggested possible spectroscopy applications. We also studied the optical properties of periodic hole-arrays with resonant frequencies in the THz region. Although the transmittance spectra of these structures have been extensively studied, here we present reflectance measurements that allow the analysis of the extinction/absorption spectra. The results were compared to predictions from the trapped-mode theory on the ohmic losses of these systems. Our results did not support the prediction of a suppression of the R + T spectra at the resonant frequency. Also, we studied the time-dependence of femtosecond pulses reflected from periodic hole arrays with resonant frequencies in the NIR region. Our results show that if the trapped modes theory is correct, then the lifetime of these modes are below 100 fs. Finally, in the third project, we studied the Raman active modes of various bismuth pyrochlores Bi3/2ZnNb3/2O7 (BZN), Bi3/2ZnTa3/2O7 (BZT), Bi3/2MgNb 3/2O7 (BMN) and Bi3/2MgTa3/2O 7 (BMT), which have earned recent attention for high-frequency applications. The spectra of the four compositions are very similar, suggesting no major structural differences among these materials. The spectra were compared to those of other pyrochlores and specific discussions are offered for the assignment of each mode. Although there are clear differences between the spectra of

  10. A 6.7 GHz Methanol Maser Survey at High Galactic Latitudes

    NASA Astrophysics Data System (ADS)

    Yang, Kai; Chen, Xi; Shen, Zhi-Qiang; Li, Xiao-Qiong; Wang, Jun-Zhi; Jiang, Dong-Rong; Li, Juan; Dong, Jian; Wu, Ya-Jun; Qiao, Hai-Hua; Ren, Zhiyuan

    2017-09-01

    We performed a systematic 6.7 GHz Class II methanol maser survey using the Shanghai Tianma Radio Telescope toward targets selected from the all-sky Wide-Field Infrared Survey Explorer (WISE) point catalog. In this paper, we report the results from the survey of those at high Galactic latitudes, i.e., | b| > 2°. Of 1473 selected WISE point sources at high latitude, 17 point positions that were actually associated with 12 sources were detected with maser emission, reflecting the rarity (1%–2%) of methanol masers in the region away from the Galactic plane. Out of the 12 sources, 3 are detected for the first time. The spectral energy distribution at infrared bands shows that these new detected masers occur in the massive star-forming regions. Compared to previous detections, the methanol maser changes significantly in both spectral profiles and flux densities. The infrared WISE images show that almost all of these masers are located in the positions of the bright WISE point sources. Compared to the methanol masers at the Galactic plane, these high-latitude methanol masers provide good tracers for investigating the physics and kinematics around massive young stellar objects, because they are believed to be less affected by the surrounding cluster environment.

  11. A stable, high power optically pumped far infrared laser system

    NASA Technical Reports Server (NTRS)

    Farhoomand, Jam; Pickett, Herbert M.

    1988-01-01

    The generation of 1.25 watts of CW laser power at the 119-micron (2522.8 GHz) methanol line is reported. The maximum frequency fluctuation of the free running laser is less than + or - 100 kHz per hour. This laser has also been tested on numerous other lines ranging from 403.7 GHz (HCOOH) to 5260 GHz (CH3OD) with improved power and stability.

  12. Optical short pulse generation at high repetition rate over 80 GHz from a monolithic passively modelocked DBR laser diode

    NASA Astrophysics Data System (ADS)

    Arahira, S.; Matsui, Y.; Kunii, T.; Oshiba, S.; Ogawa, Y.

    1993-05-01

    Optical short pulses at high repetition rate over 80 GHz were successfully generated using a monolithically fabricated passively modelocked distributed Bragg reflector laser diode for the first time. By using linear fibre compression, a transform-limited optical pulse train with a duration of 2.7 ps was obtained. The pulse envelope closely matched a sech(sup 2) waveform.

  13. Highly resistive Mn-Zn ferrite films prepared from aqueous solution for GHz conducted noise suppressors

    NASA Astrophysics Data System (ADS)

    Matsushita, Nobuhiro; Abe, Tatsunobu; Kondo, Koichi; Yoshida, Shigeyoshi; Abe, Masanori

    2005-05-01

    We have prepared Mn-Zn ferrite films (MnxZnyFezO4.00-δ: 0.23highly permeable in GHz range. The film resistivity ρ increased as the amount of Fe content z decreased and very high surface resistance R>108Ω/sq was attained for the film having z<2.6. The deposited Mn-Zn ferrite films had a large saturation magnetization Ms=380-460emu/cm3 and relatively low coercivity Hc=11-29Oe. The Mn-Zn ferrite films contacted to a microstrip line (50Ω) exhibited very large transmission loss ΔPloss per thickness t, ΔPloss/t, of about 10 times larger than that of commercialized composite sheet. They exhibited sufficiently low reflection coefficient S11<-10dB. These films were applicable as noise current suppressors deposited on an interlayer of multilayer printed circuit boards.

  14. RF dosimetry: a comparison between power absorption of female and male numerical models from 0.1 to 4 GHz

    NASA Astrophysics Data System (ADS)

    Sandrini, L.; Vaccari, A.; Malacarne, C.; Cristoforetti, L.; Pontalti, R.

    2004-11-01

    Realistic numerical models of human subjects and their surrounding environment represent the basic points of radiofrequency (RF) electromagnetic dosimetry. This also involves differentiating the human models in men and women, possibly with different body shapes and postures. In this context, the aims of this paper are, firstly, to propose a female dielectric anatomical model (fDAM) and, secondly, to compare the power absorption distributions of a male and a female model from 0.1 to 4 GHz. For realizing the fDAM, a magnetic resonance imaging tomographer to acquire images and a recent technique which avoids the discrete segmentation of body tissues into different types have been used. Simulations have been performed with the FDTD method by using a novel filtering-based subgridding algorithm. The latter is applied here for the first time to dosimetry, allowing an abrupt mesh refinement by a factor of up to 7. The results show that the whole-body-averaged specific absorption rate (WBA-SAR) of the female model is higher than that of the male counterpart, mainly because of a thicker subcutaneous fat layer. In contrast, the maximum averaged SAR over 1 g (1gA-SAR) and 10 g (10gA-SAR) does not depend on gender, because it occurs in regions where no subcutaneous fat layer is present.

  15. High-dynamic-range linear analog data links (1-20 GHz) using room temperature DFB laser diodes

    NASA Astrophysics Data System (ADS)

    White, Ian H.; Hartmann, Peter; Ingham, Jonathan D.; Webster, Matthew; Wake, David; Wonfor, Adrian; Penty, Richard V.; Seeds, Alwyn J.; White, J. Kenton

    2004-02-01

    We report the analysis and application of uncooled, directly-modulated high-speed DFB lasers with emphasis on their analogue transmission performance. Fibre-optic links employing such lasers are shown to meet the most stringent requirements of analogue systems at both high carrier frequencies and high temperatures. Spurious-free dynamic ranges (SFDR) exceeding 100dB×Hz2/3 and 90dB×Hz2/3 and input third-order intercept points (IIP3) above 20dBm and 18dBm are reported for carrier frequencies up to 20GHz at 25°C and up to 10GHz at 85°C, respectively. The error-vector magnitude (EVM) for a 256-QAM modulated signal transmitted over 15km of SMF remains below 1.9% for carrier frequencies of both 2GHz and 5GHz for all measured temperatures. The link performance is assessed by using 3GPP W-CDMA, IEEE 802.11a and IEEE 802.11b signals. In all cases the EVM remains within the standard specification, for fibre-optic link lengths of up to 10km and laser operating temperatures of up to 70°C. Finally, an IEEE 802.11b WLAN demonstrator is presented, allowing antenna remoting over up to 1000m of 62.5/125μm MMF.

  16. High power phase shifter

    SciTech Connect

    Foster, B.; Gonin, I.; Khabiboulline, T.; Makarov, A.; Solyak, N.; Terechkine, I.; Wildman, D.; /Fermilab

    2005-05-01

    One of the approaches to power distribution system of a superconducting proton linac under discussion at FNAL requires development of a fast-action, megawatt-range phase shifter. Using a couple of this kind of devices with a waveguide hybrid junction can allow independent control of phase and amplitude of RF power at the input of each superconducting cavity, which will result in significant saving in number of klystrons and modulators required for the accelerator. A prototype of a waveguide version of the shifter that uses Yttrium-Iron Garnet (YIG) blocks was developed and tested. This report presents design concept of the device, and main results of simulation and proof-of-principle tests.

  17. Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices

    NASA Astrophysics Data System (ADS)

    Gamzina, Diana

    Diana Gamzina March 2016 Mechanical and Aerospace Engineering Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices Abstract A methodology for performing thermo-mechanical design and analysis of high frequency and high average power vacuum electron devices is presented. This methodology results in a "first-pass" engineering design directly ready for manufacturing. The methodology includes establishment of thermal and mechanical boundary conditions, evaluation of convective film heat transfer coefficients, identification of material options, evaluation of temperature and stress field distributions, assessment of microscale effects on the stress state of the material, and fatigue analysis. The feature size of vacuum electron devices operating in the high frequency regime of 100 GHz to 1 THz is comparable to the microstructure of the materials employed for their fabrication. As a result, the thermo-mechanical performance of a device is affected by the local material microstructure. Such multiscale effects on the stress state are considered in the range of scales from about 10 microns up to a few millimeters. The design and analysis methodology is demonstrated on three separate microwave devices: a 95 GHz 10 kW cw sheet beam klystron, a 263 GHz 50 W long pulse wide-bandwidth sheet beam travelling wave tube, and a 346 GHz 1 W cw backward wave oscillator.

  18. Self-Aligned GaAs JFETs for Low-Power Microwave Amplifiers and RFICs at 2.4 GHz

    SciTech Connect

    Baca, A.G.; Dubbert, D.F.; Greenway, D.; Hietala, V.M.; Shul, R.J.; Sloan, L.R.; Zolper, J.C.

    1998-11-02

    Self-aligned GaAs JFET narrowband amplifiers operating at 2.4 GHz were designed and fabricated with both discrete WETS as a hybrid amplifier and as RFICS. Enhancement-mode JFETs were used in order to be compatible with complementary digital logic. Hybrid amplifiers achieved 8-10 dB of gain at 2.4 GHz and 1 mW DC bias level. The RFIC achieved 10 dB of gain at 24 GHz and 2 mW DC bias level.

  19. Standoff imaging of a masked human face using a 670 GHz high resolution radar

    NASA Astrophysics Data System (ADS)

    Kjellgren, Jan; Svedin, Jan; Cooper, Ken B.

    2011-11-01

    This paper presents an exploratory attempt to use high-resolution radar measurements for face identification in forensic applications. An imaging radar system developed by JPL was used to measure a human face at 670 GHz. Frontal views of the face were measured both with and without a ski mask at a range of 25 m. The realized spatial resolution was roughly 1 cm in all three dimensions. The surfaces of the ski mask and the face were detected by using the two dominating reflections from amplitude data. Various methods for visualization of these surfaces are presented. The possibility to use radar data to determine certain face distance measures between well-defined face landmarks, typically used for anthropometric statistics, was explored. The measures used here were face length, frontal breadth and interpupillary distance. In many cases the radar system seems to provide sufficient information to exclude an innocent subject from suspicion. For an accurate identification it is believed that a system must provide significantly more information.

  20. 95 GHz gyrotron with ferroelectric cathode.

    PubMed

    Einat, M; Pilossof, M; Ben-Moshe, R; Hirshbein, H; Borodin, D

    2012-11-02

    Ferroelectric cathodes were reported as a feasible electron source for microwave tubes. However, due to the surface plasma emission characterizing this cathode, operation of millimeter wave tubes based on it remains questionable. Nevertheless, the interest in compact high power sources of millimeter waves and specifically 95 GHz is continually growing. In this experiment, a ferroelectric cathode is used as an electron source for a gyrotron with the output frequency extended up to 95 GHz. Power above a 5 kW peak and ~0.5 μs pulses are reported; a duty cycle of 10% is estimated to be achievable.

  1. Optimization of high-definition video coding and hybrid fiber-wireless transmission in the 60 GHz band.

    PubMed

    Lebedev, Alexander; Pham, Tien Thang; Beltrán, Marta; Yu, Xianbin; Ukhanova, Anna; Llorente, Roberto; Monroy, Idelfonso Tafur; Forchhammer, Søren

    2011-12-12

    The paper addresses the problem of distribution of high-definition video over fiber-wireless networks. The physical layer architecture with the low complexity envelope detection solution is investigated. We present both experimental studies and simulation of high quality high-definition compressed video transmission over 60 GHz fiber-wireless link. Using advanced video coding we satisfy low complexity and low delay constraints, meanwhile preserving the superb video quality after significantly extended wireless distance.

  2. Review of Millimeter-Wave Integrated Circuits With Low Power Consumption for High Speed Wireless Communications

    NASA Astrophysics Data System (ADS)

    Ellinger, Frank; Fritsche, David; Tretter, Gregor; Leufker, Jan Dirk; Yodprasit, Uroschanit; Carta, C.

    2017-01-01

    In this paper we review high-speed radio-frequency integrated circuits operating up to 210 GHz and present selected state-of-the-art circuits with leading-edge performance, which we have designed at our chair. The following components are discussed employing bipolar complementary metal oxide semiconductors (BiCMOS) technologies: a 200 GHz amplifier with 17 dB gain and around 9 dB noise figure consuming only 18 mW, a 200 GHz down mixer with 5.5 dB conversion gain and 40 mW power consumption, a 190 GHz receiver with 47 dB conversion gain and 11 dB noise figure and a 60 GHz power amplifier with 24.5 dBm output power and 12.9 % power added efficiency (PAE). Moreover, we report on a single-core flash CMOS analogue-to-digital converter (ADC) with 3 bit resolution and a speed of 24 GS/s. Finally, we discuss a 60 GHz on-off keying (OOK) BiCMOS transceiver chip set. The wireless transmission of data with 5 Gb/s at 42 cm distance between transmitter and receiver was verified by experiments. The complete transceiver consumes 396 mW.

  3. High peak power gyroklystron with an inverted magnetron injection gun

    SciTech Connect

    Read, Michael E.; Lawson, Wesley; Miram, George; Marsden, David; Borchard, Philipp

    2005-12-01

    Calabazas Creek Research Inc. (CCR) has investigated the feasibility of a 30 GHz gyroklystron amplifier for driving advanced accelerators. Gyroklystrons have been shown to be efficient sources of high power radiation at frequencies above X-Band and are, therefore, well suited for driving high frequency accelerators. CCR's gyroklystron design includes a novel inverted magnetron injection gun (MIG) that allows support and cooling of the coaxial inner conductor of the circuit. This novel gun provides a very high quality electron beam, making it possible to achieve a cavity design with an efficiency of 54%. During Phase I, it was determined that the original frequency of 17 GHz was no longer well matched to the potential market. A survey of accelerator needs identified the Compact Linear Collider (CLIC) as requiring 30 GHz sources for testing of accelerator structures. Developers at CLIC are seeking approximately 25 MW per tube. This will result in the same power density as in the original 80 MW, 17 GHz device and will thus have essentially the same risk. CLIC will require initially 3-4 tubes and eventually 12-16 tubes. This quantity represents $5M-$10M in sales. In addition, gyroklystrons are of interest for radar systems and electron paramagnetic resonance (EPR) instruments. Following discussions with the Department of Energy, it was determined that changing the program goal to the CLIC requirement was in the best interest of CCR and the funding agency. The Phase I program resulted in a successful gyroklystron design with a calculated efficiency of 54% with an output power of 33 MW. Design calculations for all critical components are complete, and no significant technical issues remain.

  4. High-power MIXSEL: an integrated ultrafast semiconductor laser with 6.4 W average power.

    PubMed

    Rudin, B; Wittwer, V J; Maas, D J H C; Hoffmann, M; Sieber, O D; Barbarin, Y; Golling, M; Südmeyer, T; Keller, U

    2010-12-20

    High-power ultrafast lasers are important for numerous industrial and scientific applications. Current multi-watt systems, however, are based on relatively complex laser concepts, for example using additional intracavity elements for pulse formation. Moving towards a higher level of integration would reduce complexity, packaging, and manufacturing cost, which are important requirements for mass production. Semiconductor lasers are well established for such applications, and optically-pumped vertical external cavity surface emitting lasers (VECSELs) are most promising for higher power applications, generating the highest power in fundamental transverse mode (>20 W) to date. Ultrashort pulses have been demonstrated using passive modelocking with a semiconductor saturable absorber mirror (SESAM), achieving for example 2.1-W average power, sub-100-fs pulse duration, and 50-GHz pulse repetition rate. Previously the integration of both the gain and absorber elements into a single wafer was demonstrated with the MIXSEL (modelocked integrated external-cavity surface emitting laser) but with limited average output power (<200 mW). We have demonstrated the power scaling concept of the MIXSEL using optimized quantum dot saturable absorbers in an antiresonant structure design combined with an improved thermal management by wafer removal and mounting of the 8-µm thick MIXSEL structure directly onto a CVD-diamond heat spreader. The simple straight cavity with only two components has generated 28-ps pulses at 2.5-GHz repetition rate and an average output power of 6.4 W, which is higher than for any other modelocked semiconductor laser.

  5. A novel high power X-band ferrite phase shifter

    NASA Astrophysics Data System (ADS)

    Deng, G. J.; Huang, W. H.; Li, J. W.; Ba, T.; Guo, L. T.; Jiang, Y.

    2017-01-01

    A novel high power X-band ferrite phase shifter (PS) employing the structure of several waveguides connected in parallel is proposed. Each of the waveguides is a phase shift unit utilizing a dual-toroid structure. First, the phase shift unit is designed, manufactured, and tested. The results indicate that the power capacity reaches 115 kW. At this power, the maximum magnetic field strength of ferrite is 7.9 kA/m, beyond which the nonlinear effect of ferrite will occur. On this basis, the PS that consists of four units connected in parallel is designed. According to the threshold of ferrite, the power capacity of the PS can theoretically reach 430 kW. Limited by the maximum output power of the microwave source, the preliminary high-power test results demonstrate that the PS can operate properly at 270 kW. The PS exhibits an insertion loss of 0.82 dB and a maximum differential phase shift of approximately 300° at 9.3 GHz. The return loss of the PS is more than 16 dB from 9.0 to 9.5 GHz.

  6. A novel high power X-band ferrite phase shifter.

    PubMed

    Deng, G J; Huang, W H; Li, J W; Ba, T; Guo, L T; Jiang, Y

    2017-01-01

    A novel high power X-band ferrite phase shifter (PS) employing the structure of several waveguides connected in parallel is proposed. Each of the waveguides is a phase shift unit utilizing a dual-toroid structure. First, the phase shift unit is designed, manufactured, and tested. The results indicate that the power capacity reaches 115 kW. At this power, the maximum magnetic field strength of ferrite is 7.9 kA/m, beyond which the nonlinear effect of ferrite will occur. On this basis, the PS that consists of four units connected in parallel is designed. According to the threshold of ferrite, the power capacity of the PS can theoretically reach 430 kW. Limited by the maximum output power of the microwave source, the preliminary high-power test results demonstrate that the PS can operate properly at 270 kW. The PS exhibits an insertion loss of 0.82 dB and a maximum differential phase shift of approximately 300° at 9.3 GHz. The return loss of the PS is more than 16 dB from 9.0 to 9.5 GHz.

  7. Plasma-Based Tunable High Frequency Power Limiter

    NASA Astrophysics Data System (ADS)

    Semnani, Abbas; Macheret, Sergey; Peroulis, Dimitrios

    2016-09-01

    Power limiters are often employed to protect sensitive receivers from being damaged or saturated by high-power incoming waves. Although wideband low-power limiters based on semiconductor technology are widely available, the options for high-power frequency-selective ones are very few. In this work, we study the application of a gas discharge tube (GDT) integrated in an evanescent-mode (EVA) cavity resonator as a plasma-based power limiter. Plasmas can inherently handle higher power in comparison with semiconductor diodes. Also, using a resonant structure provides the ability of having both lower threshold power and frequency-selective limiting, which are important if only a narrowband high-power signal is targeted. Higher input RF power results in stronger discharge in the GDT and consequently higher electron density which results in larger reflection. It is also possible to tune the threshold power by pre-ionizing the GDT with a DC bias voltage. As a proof of concept, a 2-GHz EVA resonator loaded by a 90-V GDT was fabricated and measured. With reasonable amount of insertion loss, the limiting threshold power was successfully tuned from 8.3 W to 590 mW when the external DC bias was varied from 0 to 80 V. The limiter performed well up to 100 W of maximum available input power.

  8. Evolution of and High-Energy Emission from GHz-Peaked Spectrum Sources

    NASA Astrophysics Data System (ADS)

    Stawarz, Ł.; Ostorero, L.; Begelman, M. C.; Moderski, R.; Kataoka, J.; Wagner, S.

    2008-06-01

    Here we discuss evolution and broadband emission of compact (high-energy emission component produced by inverse Compton upscattering of various surrounding photon fields by the lobes' electrons. We argue that such high-energy radiation is strong enough to account for several observed properties of GHz-peaked spectrum (GPS) radio galaxies at UV and X-ray frequencies. In addition, this emission is expected to extend up to GeV (or possibly even TeV) photon energies and can thus be probed by several modern γ-ray instruments. In particular, we suggest that GPS radio galaxies should constitute a relatively numerous class of extragalactic sources detected by GLAST.

  9. On the Evolution of and High-Energy Emission from GHz-Peaked-Spectrum Sources

    SciTech Connect

    Stawarz, L.; Ostorero, L.; Begelman, M.C.; Moderski, R.; Kataoka, J.; Wagner, S.

    2007-12-18

    Here we discuss evolution and broad-band emission of compact (< kpc) lobes in young radio sources. We propose a simple dynamical description for these objects, consisting of a relativistic jet propagating into a uniform gaseous medium in the central parts of an elliptical host. In the framework of the proposed model, we follow the evolution of ultrarelativistic electrons injected from a terminal hotspot of a jet to expanding lobes, taking into account their adiabatic energy losses as well as radiative cooling. This allows us to discuss the broad-band lobe emission of young radio sources. In particular, we argue that the observed spectral turnover in the radio synchrotron spectra of these objects cannot originate from the synchrotron self-absorption process but is most likely due to free-free absorption effects connected with neutral clouds of interstellar medium engulfed by the expanding lobes and photoionized by active centers. We also find a relatively strong and complex high-energy emission component produced by inverse-Compton up-scattering of various surrounding photon fields by the lobes electrons. We argue that such high energy radiation is strong enough to account for several observed properties of GHz-peaked-spectrum (GPS) radio galaxies at UV and X-ray frequencies. In addition, this emission is expected to extend up to GeV (or possibly even TeV) photon energies and can thus be probed by several modern {gamma}-ray instruments. In particular, we suggest that GPS radio galaxies should constitute a relatively numerous class of extragalactic sources detected by GLAST.

  10. 2250-MHz High Efficiency Microwave Power Amplifier (HEMPA)

    NASA Technical Reports Server (NTRS)

    Sims, W. Herbert; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Tnis paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  11. High Power Switch Development.

    DTIC Science & Technology

    1979-11-29

    LUBBOCK Unclassified SECURITY €! ION 0 THIS PAGE (When Doat Entered) E RT DOCUMENTATION PAGE READ INSTRUCTONS9 . , -- RBEFORE COMPLETIDG FORM off...investigations, we used the electrodes in an Ion Physics Corp. FX-15 generator made available to us by the AFWL. Considerable modifications were necessary...the high pressure vessel of such as fusion, the production of high energy- the Ion Physics Corporation FX-15 (Fig 2). The particle beams, and the

  12. Ion-implanted high microwave power indium phosphide transistors

    NASA Technical Reports Server (NTRS)

    Biedenbender, Michael D.; Kapoor, Vik J.; Messick, Louis J.; Nguyen, Richard

    1989-01-01

    Encapsulated rapid thermal annealing (RTA) has been used in the fabrication of InP power MISFETs with ion-implanted source, drain, and active-channel regions. The MISFETs had a gate length of 1.4 microns. Six to ten gate fingers per device, with individual gate finger widths of 100 or 125 microns, were used to make MISFETs with total gate widths of 0.75, 0.8, or 1 mm. The source and drain contact regions and the channel region of the MISFETs were fabricated using Si implants in InP at energies from 60 to 360 keV with doses of (1-560) x 10 to the 12th/sq cm. The implants were activated using RTA at 700 C for 30 sec in N2 or H2 ambients using an Si3N4 encapsulant. The high-power high-efficiency MISFETs were characterized at 9.7 GHz, and the output microwave power density for the RTA conditions used was as high as 2.4 W/mm. For a 1-W input at 9.7 GHz gains up to 3.7 dB were observed, with an associated power-added efficiency of 29 percent and output power density 70 percent greater than that of GaAs MESFETs.

  13. Ion-implanted high microwave power indium phosphide transistors

    NASA Technical Reports Server (NTRS)

    Biedenbender, Michael D.; Kapoor, Vik J.; Messick, Louis J.; Nguyen, Richard

    1989-01-01

    Encapsulated rapid thermal annealing (RTA) has been used in the fabrication of InP power MISFETs with ion-implanted source, drain, and active-channel regions. The MISFETs had a gate length of 1.4 microns. Six to ten gate fingers per device, with individual gate finger widths of 100 or 125 microns, were used to make MISFETs with total gate widths of 0.75, 0.8, or 1 mm. The source and drain contact regions and the channel region of the MISFETs were fabricated using Si implants in InP at energies from 60 to 360 keV with doses of (1-560) x 10 to the 12th/sq cm. The implants were activated using RTA at 700 C for 30 sec in N2 or H2 ambients using an Si3N4 encapsulant. The high-power high-efficiency MISFETs were characterized at 9.7 GHz, and the output microwave power density for the RTA conditions used was as high as 2.4 W/mm. For a 1-W input at 9.7 GHz gains up to 3.7 dB were observed, with an associated power-added efficiency of 29 percent and output power density 70 percent greater than that of GaAs MESFETs.

  14. Research on the high power cyclotron-wave rectifier

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoyun; Tuo, Xianguo; Ge, Qing; Peng, Ying

    2017-07-01

    As a key component of a Wireless Power Transmission System, a cyclotron-wave rectifier, a high power microwave to DC converter, has received more attention from scholars. This paper comprehensively analyzes various limiting factors of the output voltage and current. The results show that high frequency breakdown, the external magnetic field, and engineering realization limit the output voltage, and the space charge force limits the beam current. On this basis, by using the equivalent circuit and particle simulation, we design a cyclotron-wave rectifier with high power. The simulation results demonstrate that working at 2.45 GHz, the rectifier can obtain an output voltage of 113 kV and an output power of 791 kW. These conclusions can provide guidance for designing and application of this device.

  15. TRANSISTOR HIGH VOLTAGE POWER SUPPLY

    DOEpatents

    Driver, G.E.

    1958-07-15

    High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

  16. High Power Proton Facilities

    NASA Astrophysics Data System (ADS)

    Nagaitsev, Sergei

    2015-04-01

    This presentation will provide an overview of the capabilities and challenges of high intensity proton accelerators, such as J-PARC, Fermilab MI, SNS, ISIS, PSI, ESS (in the future) and others. The presentation will focus on lessons learned, new concepts, beam loss mechanisms and methods to mitigate them.

  17. New high resolution VLA mosaic at 1.4 GHz of the SNR Puppis A

    NASA Astrophysics Data System (ADS)

    Castelletti, G.; Dubner, G. M.; Golap, K.; Goss, W. M.

    2006-06-01

    We present new observations at 1.4 GHz of the supernova remnant (SNR) Puppis A made with the VLA in the hybrid DnC and CnB configurations (in 2003 and 2004, respectively). We observed this extended remnant (about 55' diameter) applying a mosaicking technique to combine 39 different pointings. The data were reduced using the AIPS++ software package. The multiscale clean method was used to deconvolve the image. The interferometric image was combined with single dish data extracted from the Parkes Southern Galactic Plane Survey (McClure-Griffiths et al. 2001, AJ, 551, 394) following a feathering technique which involves Fourier transforming of both the single dish and interferometric data onto identical grids. The new image produced by uniformly weighted visibility data, has a final angular resolution of 34 arcsec × 16 arcsec and an rms noise level of 0.5 mJy beam^{-1}; the improvement represents a factor of two in angular resolution and almost ten times in sensitivity compared to the best previous image of Puppis A at 1515 MHz (Dubner et al. 1991, AJ, 101, 1466; HPBW 77 arcsec × 43arcsec, rms noise 3 mJy beam^{-1}). For the first time a highly structured border encircling a diffuse, almost featureless interior was revealed in Puppis A. In particular the northern half of Puppis A displays a wealth of structure along the periphery consisting of short arcs that appear to be oriented rather perpendicular to the shock front on the northeast quadrant, but tangential to it on the northweast side.

  18. K-band high power latching switch

    NASA Astrophysics Data System (ADS)

    Mlinar, M. J.; Piotrowski, W. S.; Raue, J. E.

    1980-12-01

    A 19 GHz waveguide latching switch with a bandwidth of 1400 MHz and an exceptionally low insertion loss of 0.25 dB was demonstrated. The RF and driver ferrites are separate structures and can be optimized individually. This analysis for each structure is separately detailed. Basically, the RF section features a dual turnstile junction. The circulator consists of a dielectric tube which contains two ferrite rods, and a dielectric spacer separating the ferrite parts along the center of symmetry of the waveguide to form two turnstiles. This subassembly is indexed and locked in the center of symmetry of a uniform junction of three waveguides by the metallic transformers installed in the top and bottom walls of the housing. The switching junction and its actuating circuitry met all RF performance objectives and all shock and vibration requirements with no physical damage or performance degradation. It exceeds thermal requirements by operating over a 100 C temperature range (-44 C to +56 C) and has a high power handling capability allowing up to 100 W of CW input power.

  19. Development of a 200 W CW high efficiency traveling wave tube at 12 GHz. [for use in communication technology satellites

    NASA Technical Reports Server (NTRS)

    Christensen, J. A.; Tammaru, I.

    1974-01-01

    The design, development, and test results are reported for an experimental PPM focused, traveling-wave tube that produces 235 watts of CW RF power over 85 MHz centered at 12.080 GHz. The tube uses a coupled cavity RF circuit with a velocity taper for greater than 30 percent basic efficiency. Overall efficiency of 51 percent is achieved by means of a nine stage depressed collector designed at NASA Lewis Research Center. This collector is cooled by direct radiation to deep space.

  20. A transmitting and receiving structure for high power applications

    NASA Astrophysics Data System (ADS)

    Guo, Letian; Li, Jiawei; Huang, Wenhua; Shao, Hao; Song, Zhimin; Jiang, Yue; Deng, Guangjian

    2017-03-01

    A high-power-capacity transmitting and receiving structure (TRS) is proposed. It has the ability of transmitting the GW-level high power microwave from the microwave sources with the horizontal polarized TE11 mode and receiving the microwave signal from the target with the orthogonal polarized TE11 mode. It is realized by the cooperation of a polarization-isolation-structure (PIS) and a two-way circular TE11 mode to rectangular TE10 mode power divider. Simulation shows that from 9.65 to 9.71 GHz, its power capacity is more than 3 GW at the transmitting format. The transmitting and receiving channel have an isolation of 60 dB which can prevent the receivers connecting to the receiving channel suffering from breakdown. The insertion losses for the transmitting and receiving format are both less than 0.03 dB.

  1. Compact High Power THz Source

    SciTech Connect

    Geoffrey Krafft

    2003-08-01

    In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator, is discussed. Because the beam is recirculated, short bunches may be produced that radiate coherently in the undulator, yielding high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes is discussed.

  2. High power solid state lasers

    SciTech Connect

    Weber, H.

    1988-01-01

    These proceedings discuss the following subjects: trends in materials processing with laser radiation; slabs and high power systems; glasses and new crystals; solid state lasers at HOYA Corp.; lamps, resonators and transmission; glasses as active materials for high average power solid state lasers; flashlamp pumped GGG-crystals; alexandrite lasers; designing telescope resonators; mode operation of neodymium: YAG lasers; intracavity frequency doubling with KTP crystal and thermal effects in cylinder lasers.

  3. High average power pockels cell

    DOEpatents

    Daly, Thomas P.

    1991-01-01

    A high average power pockels cell is disclosed which reduces the effect of thermally induced strains in high average power laser technology. The pockels cell includes an elongated, substantially rectangular crystalline structure formed from a KDP-type material to eliminate shear strains. The X- and Y-axes are oriented substantially perpendicular to the edges of the crystal cross-section and to the C-axis direction of propagation to eliminate shear strains.

  4. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method.

    PubMed

    Qiu, Jiaqi; Ha, Gwanghui; Jing, Chunguang; Baryshev, Sergey V; Reed, Bryan W; Lau, June W; Zhu, Yimei

    2016-02-01

    A device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incoming dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges. Applying the EMMP to a transmission electron microscope (TEM) with any dc electron source (e.g. thermionic, Schottky, or field-emission source), a GHz stroboscopic high-duty-cycle TEM can be realized. Unlike in many recent developments in time-resolved TEM that rely on a sample pumping laser paired with a laser launching electrons from a photocathode to probe the sample, there is no laser in the presented experimental set-up. This is expected to be a significant relief for electron microscopists who are not familiar with laser systems. The EMMP and the sample are externally driven by a radiofrequency (RF) source synchronized through a delay line. With no laser pumping the sample, the problem of the pump laser induced residual heating/damaging the sample is eliminated. As many RF-driven processes can be cycled indefinitely, sampling rates of 1-50GHz become accessible. Such a GHz stroboscopic TEM would open up a new paradigm for in situ and in operando experiments to study samples externally driven electromagnetically. Complementary to the lower (MHz) repetition rates experiments enabled by laser photocathode TEM, new experiments in the multi-GHz regime will be enabled by the proposed RF design

  5. Research on calorimeter for high-power microwave measurements

    NASA Astrophysics Data System (ADS)

    Ye, Hu; Ning, Hui; Yang, Wensen; Tian, Yanmin; Xiong, Zhengfeng; Yang, Meng; Yan, Feng; Cui, Xinhong

    2015-12-01

    Based on measurement of the volume increment of polar liquid that is a result of heating by absorbed microwave energy, two types of calorimeters with coaxial capacitive probes for measurement of high-power microwave energy are designed in this paper. The first is an "inline" calorimeter, which is placed as an absorbing load at the end of the output waveguide, and the second is an "offline" calorimeter that is placed 20 cm away from the radiation horn of the high-power microwave generator. Ethanol and high density polyethylene are used as the absorbing and housing materials, respectively. Results from both simulations and a "cold test" on a 9.3 GHz klystron show that the "inline" calorimeter has a measurement range of more than 100 J and an energy absorption coefficient of 93%, while the experimental results on a 9.3 GHz relativistic backward-wave oscillator show that the device's power capacity is approximately 0.9 GW. The same experiments were also carried out for the "offline" calorimeter, and the results indicate that it can be used to eliminate the effects of the shock of the solenoid on the measurement curves and that the device has a higher power capacity of 2.5 GW. The results of the numerical simulations, the "cold tests," and the experiments show good agreement.

  6. Research on calorimeter for high-power microwave measurements

    SciTech Connect

    Ye, Hu; Ning, Hui; Yang, Wensen; Tian, Yanmin; Xiong, Zhengfeng; Yang, Meng; Yan, Feng; Cui, Xinhong

    2015-12-15

    Based on measurement of the volume increment of polar liquid that is a result of heating by absorbed microwave energy, two types of calorimeters with coaxial capacitive probes for measurement of high-power microwave energy are designed in this paper. The first is an “inline” calorimeter, which is placed as an absorbing load at the end of the output waveguide, and the second is an “offline” calorimeter that is placed 20 cm away from the radiation horn of the high-power microwave generator. Ethanol and high density polyethylene are used as the absorbing and housing materials, respectively. Results from both simulations and a “cold test” on a 9.3 GHz klystron show that the “inline” calorimeter has a measurement range of more than 100 J and an energy absorption coefficient of 93%, while the experimental results on a 9.3 GHz relativistic backward-wave oscillator show that the device’s power capacity is approximately 0.9 GW. The same experiments were also carried out for the “offline” calorimeter, and the results indicate that it can be used to eliminate the effects of the shock of the solenoid on the measurement curves and that the device has a higher power capacity of 2.5 GW. The results of the numerical simulations, the “cold tests,” and the experiments show good agreement.

  7. A 50 MHz-1 GHz high linearity CATV amplifier with a 0.15 μm InGaAs PHEMT process

    NASA Astrophysics Data System (ADS)

    Jian, Xu; Zhigong, Wang; Ying, Zhang; Jing, Huang

    2011-07-01

    A 50 MHz-1 GHz low noise and high linearity amplifier monolithic-microwave integrated-circuit (MMIC) for cable TV is presented. A shunt AC voltage negative feedback combined with source current negative feedback is adopted to extend the bandwidth and linearity. A novel DC bias feedback is introduced to stabilize the operation point, which improved the linearity further. The circuit was fabricated with a 0.15 μm InGaAs PHEMT (pseudomorphic high electron mobility transistor) process. The test was carried out in 75 Ω systems from 50 MHz to 1 GHz. The measurement results showed that it gave a small signal gain of 16.5 dB with little gain ripples of less than ± 1 dB. An excellent noise figure of 1.7-2.9 dB is obtained in the designed band. The IIP3 is 16 dBm, which shows very good linearity. The CSO and CTB are high up to 68 dBc and 77 dBc, respectively. The chip area is 0.56 mm2 and the power dissipation is 110 mA with a 5 V supply. It is ideally suited to cable TV systems.

  8. Generation of 167 W infrared and 124 W green power from a 1.3-GHz, 1-ps rod fiber amplifier.

    PubMed

    Zhao, Zhi; Dunham, Bruce M; Wise, Frank W

    2014-10-20

    We report on the direct amplification of 1-ps pulses at 1.3 GHz repetition rate by using a large mode area rod fiber amplifier. An average power of 167 W at 1040 nm with nearly transform-limited duration is generated and converted into 124 W average green power through second harmonic generation. Both infrared and green pulses exhibit diffraction-limited beam quality. A frequency doubling efficiency of 75% and a pump-to-green efficiency of 45% have been achieved, which are to our knowledge the highest reported for fiber laser systems.

  9. High power ferrite microwave switch

    NASA Technical Reports Server (NTRS)

    Bardash, I.; Roschak, N. K.

    1975-01-01

    A high power ferrite microwave switch was developed along with associated electronic driver circuits for operation in a spaceborne high power microwave transmitter in geostationary orbit. Three units were built and tested in a space environment to demonstrate conformance to the required performance characteristics. Each unit consisted of an input magic-tee hybrid, two non-reciprocal latching ferrite phase shifters, an out short-slot 3 db quadrature coupler, a dual driver electronic circuit, and input logic interface circuitry. The basic mode of operation of the high power ferrite microwave switch is identical to that of a four-port, differential phase shift, switchable circulator. By appropriately designing the phase shifters and electronic driver circuits to operate in the flux-transfer magnetization mode, power and temperature insensitive operation was achieved. A list of the realized characteristics of the developed units is given.

  10. 180-GHz Interferometric Imager

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka P.; Lim, Boon H.; O'Dwyer, Ian J.; Soria, Mary M.; Owen, Heather R.; Gaier, Todd C.; Lambrigtsen, Bjorn, H.; Tanner, Alan B.; Ruf, Christopher

    2011-01-01

    A 180-GHz interferometric imager uses compact receiver modules, combined high- and low-gain antennas, and ASIC (application specific integrated circuit) correlator technology, enabling continuous, all-weather observations of water vapor with 25-km resolution and 0.3-K noise in 15 minutes of observation for numerical weather forecasting and tropical storm prediction. The GeoSTAR-II prototype instrument is broken down into four major subsystems: the compact, low-noise receivers; sub-array modules; IF signal distribution; and the digitizer/correlator. Instead of the single row of antennas adopted in GeoSTAR, this version has four rows of antennas on a coarser grid. This dramatically improves the sensitivity in the desired field of view. The GeoSTAR-II instrument is a 48-element, synthetic, thinned aperture radiometer operating at 165-183 GHz. The instrument has compact receivers integrated into tiles of 16 elements in a 4x4 arrangement. These tiles become the building block of larger arrays. The tiles contain signal distribution for bias controls, IF signal, and local oscillator signals. The IF signals are digitized and correlated using an ASIC correlator to minimize power consumption. Previous synthetic aperture imagers have used comparatively large multichip modules, whereas this approach uses chip-scale modules mounted on circuit boards, which are in turn mounted on the distribution manifolds. This minimizes the number of connectors and reduces system mass. The use of ASIC technology in the digitizers and correlators leads to a power reduction close to an order of magnitude.

  11. High resolution, wide field of view, real time 340GHz 3D imaging radar for security screening

    NASA Astrophysics Data System (ADS)

    Robertson, Duncan A.; Macfarlane, David G.; Hunter, Robert I.; Cassidy, Scott L.; Llombart, Nuria; Gandini, Erio; Bryllert, Tomas; Ferndahl, Mattias; Lindström, Hannu; Tenhunen, Jussi; Vasama, Hannu; Huopana, Jouni; Selkälä, Timo; Vuotikka, Antti-Jussi

    2017-05-01

    The EU FP7 project CONSORTIS (Concealed Object Stand-Off Real-Time Imaging for Security) is developing a demonstrator system for next generation airport security screening which will combine passive and active submillimeter wave imaging sensors. We report on the development of the 340 GHz 3D imaging radar which achieves high volumetric resolution over a wide field of view with high dynamic range and a high frame rate. A sparse array of 16 radar transceivers is coupled with high speed mechanical beam scanning to achieve a field of view of 1 x 1 x 1 m3 and a 10 Hz frame rate.

  12. 60-GHz integrated-circuit high data rate quadriphase shift keying exciter and modulator

    NASA Technical Reports Server (NTRS)

    Grote, A.; Chang, K.

    1984-01-01

    An integrated-circuit quadriphase shift keying (QPSK) exciter and modulator have demonstrated excellent performance directly modulating a carrier frequency of 60 GHz with an output phase error of less than 3 degrees and maximum amplitude error of 0.5 dB. The circuit consists of a 60-GHz Gunn VCO phase-locked to a low-frequency reference source, a 4th subharmonic mixer, and a QPSK modlator packaged into a small volume of 1.8 x 2.5 x 0.35 in. The use of microstrip has the advantages of small size, light-weight, and low-cost fabrication. The unit has the potential for multigigabit data rate applications.

  13. TlCaBaCuO high Tc superconducting microstrip ring resonators designed for 12 GHz

    NASA Technical Reports Server (NTRS)

    Subramanyam, G.; Kapoor, V. J.; Chorey, C. M.; Bhasin, K. B.

    1993-01-01

    Microwave properties of sputtered Tl-Ca-Ba-Cu-O thin films were investigated by designing, fabricating, and testing microstrip ring resonators. Ring resonators designed for 12 GHz fundamental resonance frequency, were fabricated and tested. From the unloaded Q values for the resonators, the surface resistance was calculated by separating the conductor losses from the total losses. The penetration depth was obtained from the temperature dependence of resonance frequency, assuming that the shift in resonance frequency is mainly due to the temperature dependence of penetration depth. The effective surface resistance at 12 GHz and 77 K was determined to be between 1.5 and 2.75 mOmega, almost an order lower than Cu at the same temperature and frequency. The effective penetration depth at 0 K is approximately 7000 A.

  14. Generation of high-power laser light with Gigahertz splitting.

    PubMed

    Unks, B E; Proite, N A; Yavuz, D D

    2007-08-01

    We demonstrate the generation of two high-power laser beams whose frequencies are separated by the ground state hyperfine transition frequency in (87)Rb. The system uses a single master diode laser appropriately shifted by high frequency acousto-optic modulators and amplified by semiconductor tapered amplifiers. This produces two 1 W laser beams with a frequency spacing of 6.834 GHz and a relative frequency stability of 1 Hz. We discuss possible applications of this apparatus, including electromagnetically induced transparency-like effects and ultrafast qubit rotations.

  15. Temperature measurements of a high-power microwave feedhorn window

    NASA Astrophysics Data System (ADS)

    Hoppe, Daniel J.; Perez, Raul M.; Glazer, Stuart D.

    1990-06-01

    Temperature measurements of a high-power microwave feedhorn window, obtained using an imaging IR radiometer during transmitter operation at 365 kW CW and 8.5 GHz, are discussed. The window under investigation was constructed of HTP-6, a high-thermal-performance material developed to shield the Space Shuttle Orbiter from the heat of reentry. The measurement technique is described, and experimental results are presented. The window performed adequately at 365 kW CW with a center temperature of 475 C. The tests verify that HTP-6 can be used as a window material or a support structure in high-power waveguides at power densities of 1.47 kW/sq cm for extended periods of time, with no change in its mechanical characteristics.

  16. Temperature measurements of a high-power microwave feedhorn window

    NASA Technical Reports Server (NTRS)

    Hoppe, Daniel J.; Perez, Raul M.; Glazer, Stuart D.

    1990-01-01

    Temperature measurements of a high-power microwave feedhorn window, obtained using an imaging IR radiometer during transmitter operation at 365 kW CW and 8.5 GHz, are discussed. The window under investigation was constructed of HTP-6, a high-thermal-performance material developed to shield the Space Shuttle Orbiter from the heat of reentry. The measurement technique is described, and experimental results are presented. The window performed adequately at 365 kW CW with a center temperature of 475 C. The tests verify that HTP-6 can be used as a window material or a support structure in high-power waveguides at power densities of 1.47 kW/sq cm for extended periods of time, with no change in its mechanical characteristics.

  17. Temperature measurements of a high-power microwave feedhorn window

    NASA Technical Reports Server (NTRS)

    Hoppe, Daniel J.; Perez, Raul M.; Glazer, Stuart D.

    1990-01-01

    Temperature measurements of a high-power microwave feedhorn window, obtained using an imaging IR radiometer during transmitter operation at 365 kW CW and 8.5 GHz, are discussed. The window under investigation was constructed of HTP-6, a high-thermal-performance material developed to shield the Space Shuttle Orbiter from the heat of reentry. The measurement technique is described, and experimental results are presented. The window performed adequately at 365 kW CW with a center temperature of 475 C. The tests verify that HTP-6 can be used as a window material or a support structure in high-power waveguides at power densities of 1.47 kW/sq cm for extended periods of time, with no change in its mechanical characteristics.

  18. 110 GHz ECH on DIII-D: System overview and initial operation

    SciTech Connect

    Cary, W.P.; Allen, J.C.; Callis, R.W.; Doane, J.L.; Harris, T.E.; Moeller, C.P.; Nerem, A.; Prater, R.; Remsen, D.

    1991-11-01

    A new high power electron cyclotron heating (ECH) system has been introduced on D3-D. This system is designed to operate at 110 GHz with a total output power of 2 MW. The system consists of four Varian VGT-8011 gyrotrons, (output power of 500 kW), and their associated support equipment. All components have been designed for up to a 10 second pulse duration. The 110 GHz system is intended to further progress in rf current drive experiments on D3-D when used in conjunction with the existing 60 GHz ECH (1.6 MW), and the 30--60 MHz ICH (2 MW) systems. H-mode physics, plasma stabilization experiments and transport studies are also to be conducted at 110 GHz. The present system design philosophy was based on experience gained from the existing 60 GHz ECH system. The consequences of these design decisions will be addressed as will the actual performance of various 110 GHz components.

  19. High Efficiency Ka-Band Solid State Power Amplifier Waveguide Power Combiner

    NASA Technical Reports Server (NTRS)

    Wintucky, Edwin G.; Simons, Rainee N.; Chevalier, Christine T.; Freeman, Jon C.

    2010-01-01

    A novel Ka-band high efficiency asymmetric waveguide four-port combiner for coherent combining of two Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifiers (SSPAs) having unequal outputs has been successfully designed, fabricated and characterized over the NASA deep space frequency band from 31.8 to 32.3 GHz. The measured combiner efficiency is greater than 90 percent, the return loss greater than 18 dB and input port isolation greater than 22 dB. The manufactured combiner was designed for an input power ratio of 2:1 but can be custom designed for any arbitrary power ratio. Applications considered are NASA s space communications systems needing 6 to 10 W of radio frequency (RF) power. This Technical Memorandum (TM) is an expanded version of the article recently published in Institute of Engineering and Technology (IET) Electronics Letters.

  20. Power combination of a self-coherent high power microwave source

    SciTech Connect

    Yan, Xiaolu Zhang, Xiaoping; Li, Yangmei; Dang, Fangchao; Zhang, Jun

    2015-09-15

    In our previous work, generating two phase-locked high power microwaves (HPMs) in a single self-coherent HPM device has been demonstrated. In this paper, after optimizing the structure of the previous self-coherent source, we design a power combiner with a folded phase-adjustment waveguide to realize power combination between its two sub-sources. Further particle-in-cell simulation of the combined source shows that when the diode voltage is 687 kV and the axial magnetic field is 0.8 T, a combined output microwave with 3.59 GW and 9.72 GHz is generated. The impedance of the combined device is 36 Ω and the total power conversion efficiency is 28%.

  1. High power test of a wideband diplexer with short-slotted metal half mirrors for electron cyclotron current drive system

    SciTech Connect

    Saigusa, M.; Atsumi, K.; Yamaguchi, T.; Nagashima, K.; Oda, Y.; Fukunari, M.; Sakamoto, K.

    2014-02-12

    The wideband high power diplexer has been developed for combining and fast switching of high power millimeter waves generated by a dual frequency gyrotron. The actual diplexer was tested at the frequency band of 170 GHz in low power. After adjusting a resonant frequency of diplexer for the gyrotron frequency, the evacuated wideband diplexer with short-slotted metal half mirrors was tested at an incident power of about 150 kW, a pulse duration of 30 ms and a frequency band of 170.2–170.3 GHz. Any discharge damage was not observed in the diplexer.

  2. High-power solid-state cw dye laser.

    PubMed

    Bornemann, R; Thiel, E; Bolívar, P Haring

    2011-12-19

    In the present paper we describe a high-power tunable solid-state dye laser setup that offers peak output power up to 800 mW around 575 nm with excellent long-time power stability and low noise level. The spectral width of the laser emission is less than 3 GHz and can be tuned over more than 30 nm. A nearly circular mode profile is achieved with an M(2) better than 1.4. The device can be integrated in a compact housing (dimensions are 60 × 40 × 20 cm(3)). The limitation of long-time power stability is mainly given by photo decomposition of organic dye molecules. These processes are analyzed in detail via spatially resolved micro-imaging and spectroscopic studies.

  3. FIRST SEASON QUIET OBSERVATIONS: MEASUREMENTS OF COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRA AT 43 GHz IN THE MULTIPOLE RANGE 25 {<=} l {<=} 475

    SciTech Connect

    Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.; Smith, K. M.; Chinone, Y.; Cleary, K.; Reeves, R.; Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L.; Monsalve, R.; Bustos, R.; Naess, S. K.; Eriksen, H. K.; Wehus, I. K.; Zuntz, J. A.; Bronfman, L.; Church, S. E.; Dickinson, C.

    2011-11-10

    The Q/U Imaging ExperimenT (QUIET) employs coherent receivers at 43 GHz and 94 GHz, operating on the Chajnantor plateau in the Atacama Desert in Chile, to measure the anisotropy in the polarization of the cosmic microwave background (CMB). QUIET primarily targets the B modes from primordial gravitational waves. The combination of these frequencies gives sensitivity to foreground contributions from diffuse Galactic synchrotron radiation. Between 2008 October and 2010 December, over 10,000 hr of data were collected, first with the 19 element 43 GHz array (3458 hr) and then with the 90 element 94 GHz array. Each array observes the same four fields, selected for low foregrounds, together covering Almost-Equal-To 1000 deg{sup 2}. This paper reports initial results from the 43 GHz receiver, which has an array sensitivity to CMB fluctuations of 69 {mu}K{radical}s. The data were extensively studied with a large suite of null tests before the power spectra, determined with two independent pipelines, were examined. Analysis choices, including data selection, were modified until the null tests passed. Cross-correlating maps with different telescope pointings is used to eliminate a bias. This paper reports the EE, BB, and EB power spectra in the multipole range l = 25-475. With the exception of the lowest multipole bin for one of the fields, where a polarized foreground, consistent with Galactic synchrotron radiation, is detected with 3{sigma} significance, the E-mode spectrum is consistent with the {Lambda}CDM model, confirming the only previous detection of the first acoustic peak. The B-mode spectrum is consistent with zero, leading to a measurement of the tensor-to-scalar ratio of r = 0.35{sup +1.06}{sub -0.87}. The combination of a new time-stream 'double-demodulation' technique, side-fed Dragonian optics, natural sky rotation, and frequent boresight rotation leads to the lowest level of systematic contamination in the B-mode power so far reported, below the level of r

  4. Integrated high power VCSEL systems

    NASA Astrophysics Data System (ADS)

    Moench, Holger; Conrads, Ralf; Gronenborn, Stephan; Gu, Xi; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

    2016-03-01

    High power VCSEL systems are a novel laser source used for thermal treatment in industrial manufacturing. These systems will be applied in many applications, which have not used a laser source before. This is enabled by the unique combination of efficiency, compactness and robustness. High power VCSEL system technology encompasses elements far beyond the VCSEL chip itself: i.e. heat sinks, bonding technology and integrated optics. This paper discusses the optimization of these components and processes specifically for building high-power laser systems with VCSEL arrays. New approaches help to eliminate components and process steps and make the system more robust and easier to manufacture. New cooler concepts with integrated electrical and mechanical interfaces have been investigated and offer advantages for high power system design. The bonding process of chips on sub-mounts and coolers has been studied extensively and for a variety of solder materials. High quality of the interfaces as well as good reliability under normal operation and thermal cycling have been realized. A viable alternative to soldering is silver sintering. The very positive results which have been achieved with a variety of technologies indicate the robustness of the VCSEL chips and their suitability for high power systems. Beam shaping micro-optics can be integrated on the VCSEL chip in a wafer scale process by replication of lenses in a polymer layer. The performance of VCSEL arrays with integrated collimation lenses has been positively evaluated and the integrated chips are fully compatible with all further assembly steps. The integrated high power systems make the application even easier and more robust. New examples in laser material processing and pumping of solid state lasers are presented.

  5. Pulsed high-power beams

    SciTech Connect

    Reginato, L.L.; Birx, D.L.

    1988-06-01

    The marriage of induction linac technology with nonlinear magnetic modulators has produced some unique capabilities. It is now possible to produce short-pulse electron beams with average currents measured in amperes, at gradients approaching 1-MeV/m, and with power efficiencies exceeding 50%. A 70-Mev, 3-kA induction accelerator (ETA II) constructed at the Lawrence Livermore National Laboratory incorporates the pulse technology concepts that have evolved over the past several years. The ETA II is a linear induction accelerator and provides a test facility for demonstration of the high-average-power components and high-brightness sources used in such accelerators. The pulse drive for the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak-power capability, repetition rates exceeding 1 kHz, and excellent reliability. 6 figs.

  6. Free electron laser with small period wiggler and sheet electron beam: A study of the feasibility of operation at 300 GHz with 1 MW CW output power

    SciTech Connect

    Booske, J.H.; Granatstein, V.L.; Antonsen, T.M. Jr.; Destler, W.W.; Finn, J.; Latham, P.E.; Levush, B.; Mayergoyz, I.D.; Radack, D.; Rodgers, J.

    1988-01-01

    The use of a small period wiggler (/ell//sub ..omega../ < 1 cm) together with a sheet electron beam has been proposed as a low cost source of power for electron cyclotron resonance heating (ECRH) in magnetic fusion plasmas. Other potential applications include space-based radar systems. We have experimentally demonstrated stable propagation of a sheet beam (18 A. 1 mm /times/ 20 mm) through a ten-period wiggler electromagnet with peak field of 1.2 kG. Calculation of microwave wall heating and pressurized water cooling have also been carried out, and indicate the feasibility of operating a near-millimeter, sheet beam FEL with an output power of 1 MW CW (corresponding to power density into the walls of 2 kW/cm/sup 2/). Based on these encouraging results, a proof-of-principle experiment is being assembled, and is aimed at demonstrating FEL operating at 120 GHz with 300 kW output power in 1 ..mu..s pulses: electron energy would be 410 keV. Preliminary design of a 300 GHz 1 MW FEL with an untapered wiggler is also presented. 10 refs., 5 figs., 3 tabs.

  7. Polarization Issues with High Power Injection and Low Power Emission in Fusion Experiments

    SciTech Connect

    Goodman, T. P.; Felici, F.; Udintsev, V. S.

    2009-11-26

    All tokamak experiments using ECCD require setting of the beam elliptical polarization for proper coupling to the plasma. This is done either in the matching optics unit (MOU) at the output of the gyrotron, or in a couple of miter bends of the transmission line. Similarly, oblique ECE receivers require selection of the correct elliptical polarization to provide localized measurements. For the TCV tokamak at the CRPP, gyrotron and oblique-ECE polarizers are characterized during either high- or low- power testing of equipment: for the gyrotrons the behaviour is determined at a single frequency, but for the oblique-ECE the broadband response is needed. These characteristics are included in the calibration database and used during subsequent analysis of the power coupling to, or from, the sources (gyrotron, plasma, or low power transmitting antenna). A more detailed characterization has been carried out (at low power) with the MOU for the EU, 170 GHz, 2 MW, gyrotron prototype for ITER. This paper discusses the methodology and results of these measurements, as well as a review of nearly a decade's worth of experimental data from the 6 gyrotron, 3 MW, 82.6 GHz TCV system. In particular, the consistency between the calibrations and the subsequent data from tokamak experiments is analysed.

  8. PolarCube: A High Resolution Passive Microwave Satellite for Sounding and Imaging at 118 GHz

    NASA Astrophysics Data System (ADS)

    Weaver, R. L.; Gallaher, D. W.; Gasiewski, A. J.; Sanders, B.; Periasamy, L.; Hwang, K.; Alvarenga, G.; Hickey, A. M.

    2013-12-01

    PolarCube is a 3U CubeSat hosting an eight-channel passive microwave spectrometer operating at the 118.7503 GHz oxygen resonance that is currently in development. The project has an anticipated launch date in early 2015. It is currently being designed to operate for approximately12 months on orbit to provide the first global 118-GHz spectral imagery of the Earth over full seasonal cycle and to sound Arctic vertical temperature structure. The principles used by PolarCube for temperature sounding are well established in number of peer-reviewed papers going back more than two decades, although the potential for sounding from a CubeSat has never before been demonstrated in space. The PolarCube channels are selected to probe atmospheric emission over a range of vertical levels from the surface to lower stratosphere. This capability has been available operationally for over three decades, but at lower frequencies and higher altitudes that do not provide the spatial resolution that will be achieved by PolarCube. While the NASA JPSS ATMS satellite sensor provides global coverage at ~32 km resolution, the PolarCube will improve on this resolution by a factor of two, thus facilitating the primary science goal of determining sea ice concentration and extent while at the same time collecting profile data on atmospheric temperature. Additionally, we seek to correlate freeze-thaw line data from SMAP with our near simultaneously collected atmospheric temperature data. In addition to polar science, PolarCube will provide a first demonstration of a very low cost passive microwave sounder that if operated in a fleet configuration would have the potential to fulfill the goals of the Precipitation Atmospheric Temperature and Humidity (PATH) mission, as defined in the NRC Decadal Survey. PolarCube 118-GHz passive microwave spectrometer in deployed configuration

  9. High-Average Power Facilities

    SciTech Connect

    Dowell, David H.; Power, John G.; /Argonne

    2012-09-05

    There has been significant progress in the development of high-power facilities in recent years yet major challenges remain. The task of WG4 was to identify which facilities were capable of addressing the outstanding R&D issues presently preventing high-power operation. To this end, information from each of the facilities represented at the workshop was tabulated and the results are presented herein. A brief description of the major challenges is given, but the detailed elaboration can be found in the other three working group summaries.

  10. Feasibility of an EHF (40/50 GHz) mobile satellite system using highly inclined orbits

    NASA Technical Reports Server (NTRS)

    Falciasecca, G.; Paraboni, A.; Ruggieri, M.; Valdoni, F.; Vatalaro, F.

    1990-01-01

    The pan-European L-band terrestrial cellular system (GSM) is expected to provide service to more than 10 million users by the year 2000. Discussed here is the feasibility of a new satellite system at EHF (40/50 GHz) to complement, at the end of the decade, the GSM system or its decendants in order to provide additional services at 64 kbits/s, or so. The main system aspects, channel characteristics, technology issues, and both on-board and earth terminal architectures are highlighted. Based on the performed analyses, a proposal was addressed to the Italian Space Agency (ASI), aimed at the implementation of a national plan.

  11. Design of high efficiency multi-GHz SiGe HBT electro-optic modulator.

    PubMed

    Deng, Shengling; Huang, Z Rena; McDonald, J F

    2009-08-03

    We design and theoretically analyze a heterojunction bipolar transistor (HBT) electro-optic (EO) modulator with a composition graded SiGe base. The waveguide has a large cross-section of 1 microm for ease of fiber alignment. At a base-emitter bias of V BE = 2.5 V, a pi-phase shift requires 74.5 microm interaction length for TM polarization at lambda = 1.55 microm. The total optical attenuation is 3.9 dB to achieve a pi-phase shift in this condition. This device is expected to operate at a switching speed of 2.4 GHz.

  12. High frequency electron nuclear double resonance at 239 GHz using a far-infrared laser source

    SciTech Connect

    Paschedag, L.; van Tol, J.; Wyder, P.

    1995-10-01

    We report on the application of {sup 14}N electron nuclear double resonance (ENDOR) at 8.5 T and 239 GHz ({lambda}=1.2 mm) in a {gamma}-irradiated betaine arsenate single crystal. A laser was used as a far-infrared radiation source in a transmission-type electron paramagnetic resonance (EPR) setup without a cavity. The four expected nitrogen ENDOR lines were observed, but due to insufficient saturation of the EPR transitions the signal/noise ratio was not larger than 10 and the signals vanished at temperatures above 20 K. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  13. Atmospheric propagation and combining of high-power lasers.

    PubMed

    Nelson, W; Sprangle, P; Davis, C C

    2016-03-01

    In this paper, we analyze beam combining and atmospheric propagation of high-power lasers for directed-energy (DE) applications. The large linewidths inherent in high-power fiber and slab lasers cause random phase and intensity fluctuations that occur on subnanosecond time scales. Coherently combining these high-power lasers would involve instruments capable of precise phase control and operation at rates greater than ∼10  GHz. To the best of our knowledge, this technology does not currently exist. This presents a challenging problem when attempting to phase lock high-power lasers that is not encountered when phase locking low-power lasers, for example, at milliwatt power levels. Regardless, we demonstrate that even if instruments are developed that can precisely control the phase of high-power lasers, coherent combining is problematic for DE applications. The dephasing effects of atmospheric turbulence typically encountered in DE applications will degrade the coherent properties of the beam before it reaches the target. Through simulations, we find that coherent beam combining in moderate turbulence and over multikilometer propagation distances has little advantage over incoherent combining. Additionally, in cases of strong turbulence and multikilometer propagation ranges, we find nearly indistinguishable intensity profiles and virtually no difference in the energy on the target between coherently and incoherently combined laser beams. Consequently, we find that coherent beam combining at the transmitter plane is ineffective under typical atmospheric conditions.

  14. Design of ultralow power receiver front-ends for 2.4 GHz wireless sensor network applications

    NASA Astrophysics Data System (ADS)

    Meng, Zhang; Zhiqun, Li; Zengqi, Wang; Chenjian, Wu; Liang, Chen

    2014-01-01

    This paper presents the design of an ultralow power receiver front-end designed for a wireless sensor network (WSN) in a 0.18 μm CMOS process. The author designs two front-ends working in the saturation region and the subthreshold region respectively. The front-ends contain a two-stage cross-coupling cascaded common-gate (CG) LNA and a quadrature Gilbert IQ mixer. The measured conversion gain is variable with high gain at 24 dB and low gain at 7 dB for the saturation one, and high gain at 22 dB and low gain at 5 dB for the subthreshold one. The noise figure (NF) at high gain mode is 5.1 dB and 6.3 dB for each. The input 1 dB compression point (IP1dB) at low gain mode is about -6 dBm and -3 dBm for each. The front-ends consume about 2.1 mA current from 1.8 V power supply for the saturation one and 1.3 mA current for the subthreshold one. The measured results show that, comparing with the power consumption saving, it is worth making sacrifices on the performance for using the subthreshold technology.

  15. The exploratory development of a high power S-band solid state radar transmitter

    NASA Astrophysics Data System (ADS)

    Hay, J. D.; Kerstenbeck, E. A.; Rahn, D. G.; Halayko, D. W.; Painchaud, G. R.

    A solid-state power amplifier has been developed using 100-W S-band silicon bipolar transistors. The amplifier produces a nominal 400-W peak output power from 2.7 GHz to 3.0 GHz, at pulse widths up to 50 microsec, at a 10 percent maximum duty cycle and 30 percent efficiency. A high-power planar hybrid combiner was also designed to combine 16 amplifiers to provide a nominal 5-kW RF output power. The isolation between combining ports ensures graceful degradation of output power should individual amplifier modules fail, and allows replacement of the modules during transmitter operation. Higher output powers can be achieved by adding more combining ports to the design or by incorporating a second stage of combining to sum the outputs from several 16-way combiners. The feasibility of solid-state radar transmitter technology at S-band is confirmed.

  16. A Novel High-Power Dual-Band Coupled-Line Gysel Power Divider with Impedance-Transforming Functions

    PubMed Central

    Wang, Weimin; Liu, Yuanan

    2014-01-01

    A novel coupled-line structure is proposed to design dual-band and high-power Gysel power dividers with inherent impedance-transforming functions. Based on traditional even- and odd-mode technique, the analytical design methods in closed-form formula are obtained and the accurate electrical parameters analysis is presented. Due to the usage of coupled-line sections, more design-parameter freedom and a wider frequency-ratio operation range for this kind of dual-band Gysel powder divider are obtained. Several numerical examples are designed and calculated to demonstrate flexible dual-band applications with different impedance-transforming functions. A practical microstrip power divider operating at 2 GHz and 3.2 GHz is designed, fabricated, and measured. The good agreement between the calculated and measured results verifies our proposed circuit structure and analytical design approach. PMID:24764768

  17. A novel high-power dual-band coupled-line Gysel power divider with impedance-transforming functions.

    PubMed

    Wang, Weimin; Wu, Yongle; Liu, Yuanan

    2014-01-01

    A novel coupled-line structure is proposed to design dual-band and high-power Gysel power dividers with inherent impedance-transforming functions. Based on traditional even- and odd-mode technique, the analytical design methods in closed-form formula are obtained and the accurate electrical parameters analysis is presented. Due to the usage of coupled-line sections, more design-parameter freedom and a wider frequency-ratio operation range for this kind of dual-band Gysel powder divider are obtained. Several numerical examples are designed and calculated to demonstrate flexible dual-band applications with different impedance-transforming functions. A practical microstrip power divider operating at 2 GHz and 3.2 GHz is designed, fabricated, and measured. The good agreement between the calculated and measured results verifies our proposed circuit structure and analytical design approach.

  18. High power neutron production targets

    SciTech Connect

    Wender, S.

    1996-06-01

    The author describes issues of concern in the design of targets and associated systems for high power neutron production facilities. The facilities include uses for neutron scattering, accelerator driven transmutation, accelerator production of tritium, short pulse spallation sources, and long pulse spallation sources. Each of these applications requires a source with different design needs and consequently different implementation in practise.

  19. 140-GHz pulsed Fourier transform microwave spectrometer

    NASA Astrophysics Data System (ADS)

    Kolbe, W. F.; Leskovar, B.

    1985-01-01

    A pulsed microwave spectrometer operating in the vicinity of 140 GHz for the detection of rotational transitions in gaseous molecules is described. The spectrometer incorporates a tunable Fabry-Perot cavity and a subharmonically pumped superheterodyne receiver for the detection of the molecular emission signals. A 70-GHz source supplying a high-efficiency frequency doubler which is pulse modulated at 30 MHz produces sidebands of sufficient power at 140 GHz to excite the molecules. The cavity is tuned to one of the modulation sidebands. The operation of the spectrometer is illustrated by the detection of emission signals from the 6(2, 4)-6(1, 5) transition of SO2 gas. The generation of the electric dipole analog of nuclear-magnetic-resonance (NMR) ``spin-echo'' signals by a π/2-π pulse sequence is also described.

  20. Implications of the high-power microwave weapon threat in electronic system design

    NASA Astrophysics Data System (ADS)

    van Keuren, E.; Knighten, J.

    The current status of high-power microwave (HPM) weapon is discussed with particular attention given to threats, sources, and possible protective techniques. Due to the GHz band frequencies involved, HPM is capable of penetrating not only radio front ends, but also the most minute shielding penetrations throughout the equipment.

  1. Submillimeter sources for radiometry using high power Indium Phosphide Gunn diode oscillators

    NASA Technical Reports Server (NTRS)

    Deo, Naresh C.

    1990-01-01

    A study aimed at developing high frequency millimeter wave and submillimeter wave local oscillator sources in the 60-600 GHz range was conducted. Sources involved both fundamental and harmonic-extraction type Indium Phosphide Gunn diode oscillators as well as varactor multipliers. In particular, a high power balanced-doubler using varactor diodes was developed for 166 GHz. It is capable of handling 100 mW input power, and typically produced 25 mW output power. A high frequency tripler operating at 500 GHz output frequency was also developed and cascaded with the balanced-doubler. A dual-diode InP Gunn diode combiner was used to pump this cascaded multiplier to produce on the order of 0.5 mW at 500 GHz. In addition, considerable development and characterization work on InP Gunn diode oscillators was carried out. Design data and operating characteristics were documented for a very wide range of oscillators. The reliability of InP devices was examined, and packaging techniques to enhance the performance were analyzed. A theoretical study of a new class of high power multipliers was conducted for future applications. The sources developed here find many commercial applications for radio astronomy and remote sensing.

  2. High voltage power transistor development

    NASA Technical Reports Server (NTRS)

    Hower, P. L.

    1981-01-01

    Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

  3. High Efficiency Power Combining of Ka-Band TWTs for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.; Simons, R. N.; Vaden, K. R.; Lesny, G. G.; Glass, J. L.

    2006-01-01

    Future NASA deep space exploration missions are expected in some cases to require telecommunication systems capable of operating at very high data rates (potentially 1 Gbps or more) for the transmission back to Earth of large volumes of scientific data, which means high frequency transmitters with large bandwidth. Among the Ka band frequencies of interest are the present 500 MHz Deep Space Network (DSN) band of 31.8 to 32.3 GHz and a broader band at 37-38 GHz allocated for space science [1]. The large distances and use of practical antenna sizes dictate the need for high transmitter power of up to 1 kW or more. High electrical efficiency is also a requirement. The approach investigated by NASA GRC is a novel wave guide power combiner architecture based on a hybrid magic-T junction for combining the power output from multiple TWTs [1,2]. This architecture was successfully demonstrated and is capable of both high efficiency (90-95%, depending on frequency) and high data rate transmission (up to 622 Mbps) in a two-way power combiner circuit for two different pairs of Ka band TWTs at two different frequency bands. One pair of TWTs, tested over a frequency range of 29.1 to 29.6 GHz, consisted of two 110-115W TWTs previously used in uplink data transmission evaluation terminals in the NASA Advanced Communications Technology Satellite (ACTS) program [1,2]. The second pair was two 100W TWTs (Boeing 999H) designed for high efficiency operation (greater than 55%) over the DSN frequency band of 31.8 to 32.3 GHz [3]. The presentation will provide a qualitative description of the wave guide circuit, results for power combining and data transmission measurements, and results of computer modeling of the magic-T and alternative hybrid junctions for improvements in efficiency and power handling capability. The power combiner results presented here are relevant not only to NASA deep space exploration missions, but also to other U.S. Government agency programs.

  4. High power, high reliability laser diodes

    NASA Astrophysics Data System (ADS)

    Scifres, D. R.; Welch, D. F.; Craig, R. R.; Zucker, E.; Major, J. S.; Harnagel, G. L.; Sakamoto, M.; Haden, J. M.; Endriz, J. G.; Kung, H.

    1992-06-01

    Results are presented on catastrophic damage limits and life-test measurements for four types of high-power laser diodes operating at wavelengths between 980 nm and 690 nm. The laser diodes under consideration are CW multimode lasers, CW laser bars, quasi-CW bars/2D stacked arrays, and single transverse mode lasers.

  5. High Power Tests of Normal Conducting Single-Cell Structures

    SciTech Connect

    Dolgashev, V.A.; Tantawi, S.G.; Nantista, C.D.; Higashi, Y.; Higo, T.; /KEK, Tsukuba

    2007-11-07

    We report the results of the first high power tests of single-cell traveling-wave and standing-wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the gradient potential of normal-conducting rf-powered particle beam accelerators. The test setup consists of reusable mode converters and short test structures and is powered by SLAC's XL-4 klystron. This setup was created for economical testing of different cell geometries, cell materials and preparation techniques with short turn-around time. The mode launchers and structures were manufactured at SLAC and KEK and tested in the SLAC Klystron Test Lab.

  6. High-Power Ka-Band Window and Resonant Ring

    SciTech Connect

    Jay L. Hirshfield

    2006-11-29

    A stand-alone 200 MW rf test station is needed for carrying out development of accelerator structures and components for a future high-gradient multi-TeV collider, such as CLIC. A high-power rf window is needed to isolate the test station from a structure element under test. This project aimed to develop such a window for use at a frequency in the range 30-35 GHz, and to also develop a high-power resonant ring for testing the window. During Phase I, successful conceptual designs were completed for the window and the resonant ring, and cold tests of each were carried out that confirmed the designs.

  7. High-power, high-efficiency FELs

    SciTech Connect

    Sessler, A.M.

    1989-04-01

    High power, high efficiency FELs require tapering, as the particles loose energy, so as to maintain resonance between the electromagnetic wave and the particles. They also require focusing of the particles (usually done with curved pole faces) and focusing of the electromagnetic wave (i.e. optical guiding). In addition, one must avoid transverse beam instabilities (primarily resistive wall) and longitudinal instabilities (i.e sidebands). 18 refs., 7 figs., 3 tabs.

  8. The faint source population at 15.7 GHz - III. A high-frequency study of HERGs and LERGs

    NASA Astrophysics Data System (ADS)

    Whittam, I. H.; Riley, J. M.; Green, D. A.; Jarvis, M. J.

    2016-10-01

    A complete sample of 96 faint (S > 0.5 mJy) radio galaxies is selected from the Tenth Cambridge (10C) survey at 15.7 GHz. Optical spectra are used to classify 17 of the sources as high-excitation or low-excitation radio galaxies (HERGs and LERGs, respectively), for the remaining sources three other methods are used; these are optical compactness, X-ray observations and mid-infrared colour-colour diagrams. 32 sources are HERGs and 35 are LERGs while the remaining 29 sources could not be classified. We find that the 10C HERGs tend to have higher 15.7-GHz flux densities, flatter spectra, smaller linear sizes and be found at higher redshifts than the LERGs. This suggests that the 10C HERGs are more core dominated than the LERGs. Lower-frequency radio images, linear sizes and spectral indices are used to classify the sources according to their radio morphology; 18 are Fanaroff and Riley type I or II sources, a further 13 show some extended emission, and the remaining 65 sources are compact and are referred to as FR0 sources. The FR0 sources are sub-divided into compact, steep-spectrum sources (13 sources) or gigahertz-peaked spectrum sources (10 sources) with the remaining 42 in an unclassified class. FR0 sources are more dominant in the subset of sources with 15.7-GHz flux densities <1 mJy, consistent with the previous result that the fainter 10C sources have flatter radio spectra. The properties of the 10C sources are compared to the higher-flux density Australia Telescope 20 GHz (AT20G) survey. The 10C sources are found at similar redshifts to the AT20G sources but have lower luminosities. The nature of the high-frequency selected objects changes as flux density decreases; at high flux densities the objects are primarily quasars, while at low flux densities radio galaxies dominate.

  9. High temperature, high power piezoelectric composite transducers.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  10. High Temperature, High Power Piezoelectric Composite Transducers

    PubMed Central

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  11. Design and fabrication of 33 GHz high-gradient accelerator sections

    SciTech Connect

    Hopkins, D.B.; Sessler, A.M.; Johnsen, H.A.; Farmer, J.C.; Kelley, W.K.; Steffani, C.P.; Haimson, J.; Mecklenburg, B.

    1988-06-01

    As part of a two-beam accelerator research program /similar to/33 GHz accelerator sections have been designed and fabricated by both the machined-and-brazed technique and the electroforming technique. These procedures are summarized in this paper. Special requirements included a filling time of about 14 ns, +- 1.25 ..mu..m dimensional tolerances, input VSWR less than or equal to1.10, radial vacuum pumping for each cell, and a capability for a 200--300 MV/m accelerating gradient. A 34-cavity, 2..pi../3 mode, quasi-constant gradient, v/sub p/ = c, /similar to/10 cm-long, disc-loaded waveguide structure design and chosen with optimized sidewall input/output iris couplers. 13 refs., 5 figs., 1 tab.

  12. 164-GHz MMIC HEMT Frequency Doubler

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene; Radisic, Vesna; Micovic, Miro; Hu, Ming; Janke, Paul; Ngo, Catherine; Nguyen, Loi; Morgan, Matthew

    2003-01-01

    A monolithic microwave integrated circuit (MMIC) that includes a high-electron-mobility transistor (HEMT) has been developed as a prototype of improved frequency doublers for generating signals at frequencies greater than 100 GHz. Signal sources that operate in this frequency range are needed for a variety of applications, notably including general radiometry and, more specifically, radiometric remote sensing of the atmosphere. Heretofore, it has been common practice to use passive (diode-based) frequency multipliers to obtain frequencies greater than 100 GHz. Unfortunately, diode-based frequency multipliers are plagued by high DC power consumption and low conversion efficiency. Moreover, multiplier diodes are not easily integrated with such other multiplier-circuit components as amplifiers and oscillators. The goals of developing the present MMIC HEMT frequency doubler were (1) to utilize the HEMT as an amplifier to increase conversion efficiency (more precisely, to reduce conversion loss), thereby increasing the output power for a given DC power consumption or, equivalently, reducing the DC power consumption for a given output power; and (2) to provide for the integration of amplifier and oscillator components on the same chip. The MMIC frequency doubler (see Figure 1) contains an AlInAs/GaInAs/InP HEMT biased at pinch-off to make it function as a class-B amplifier (meaning that it conducts in half-cycle pulses). Grounded coplanar waveguides (GCPWs) are used as impedance-matching transmission lines. Air bridges are placed at discontinuities to suppress undesired slot electromagnetic modes. Another combination of GCPWs also serves both as a low-pass filter to suppress undesired oscillations at frequencies below 60 GHz and as a DC blocker. Large decoupling capacitors and epitaxial resistors are added in the drain and gate lines to suppress bias oscillations. At the output terminal, the fundamental frequency is suppressed by a quarter-wave open stub, which presents

  13. Radially combined 30 W, 14-16 GHz amplifier

    SciTech Connect

    Sechi, F.; Bujatti, M.; Knudson, R.; Bugos, R.

    1994-04-01

    The paper describes a highly integrated 30 W power amplifier for a Synthetic Aperture Radar, operating in the 14--16 GHz band. The use of a waveguide radial combiner, a microstrip power divider and direct microstrip to waveguide miniaturized ceramic technology, leads to an unusually compact and accessible structure, well suited for commercial production.

  14. High frequency power distribution system

    NASA Technical Reports Server (NTRS)

    Patel, Mikund R.

    1986-01-01

    The objective of this project was to provide the technology of high frequency, high power transmission lines to the 100 kW power range at 20 kHz frequency. In addition to the necessary design studies, a 150 m long, 600 V, 60 A transmission line was built, tested and delivered for full vacuum tests. The configuration analysis on five alternative configurations resulted in the final selection of the three parallel Litz straps configuration, which gave a virtually concentric design in the electromagnetic sense. Low inductance, low EMI and flexibility in handling are the key features of this configuration. The final design was made after a parametric study to minimize the losses, weight and inductance. The construction of the cable was completed with no major difficulties. The R,L,C parameters measured on the cable agreed well with the calculated values. The corona tests on insulation samples showed a safety factor of 3.

  15. High frequency power distribution system

    NASA Astrophysics Data System (ADS)

    Patel, Mikund R.

    1986-04-01

    The objective of this project was to provide the technology of high frequency, high power transmission lines to the 100 kW power range at 20 kHz frequency. In addition to the necessary design studies, a 150 m long, 600 V, 60 A transmission line was built, tested and delivered for full vacuum tests. The configuration analysis on five alternative configurations resulted in the final selection of the three parallel Litz straps configuration, which gave a virtually concentric design in the electromagnetic sense. Low inductance, low EMI and flexibility in handling are the key features of this configuration. The final design was made after a parametric study to minimize the losses, weight and inductance. The construction of the cable was completed with no major difficulties. The R,L,C parameters measured on the cable agreed well with the calculated values. The corona tests on insulation samples showed a safety factor of 3.

  16. High power gas laser amplifier

    DOEpatents

    Leland, Wallace T.; Stratton, Thomas F.

    1981-01-01

    A high power output CO.sub.2 gas laser amplifier having a number of sections, each comprising a plurality of annular pumping chambers spaced around the circumference of a vacuum chamber containing a cold cathode, gridded electron gun. The electron beam from the electron gun ionizes the gas lasing medium in the sections. An input laser beam is split into a plurality of annular beams, each passing through the sections comprising one pumping chamber.

  17. High-Power Rf Load

    DOEpatents

    Tantawi, Sami G.; Vlieks, Arnold E.

    1998-09-01

    A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

  18. High power microwave beam steering based on gyromagnetic nonlinear transmission lines

    NASA Astrophysics Data System (ADS)

    Romanchenko, I. V.; Rostov, V. V.; Gunin, A. V.; Konev, V. Yu.

    2015-06-01

    We demonstrate electronically controlled beam steering by high power RF pulses produced by two gyromagnetic nonlinear transmission lines (NLTLs) connected to a one high voltage driver. Each NLTL is capable of producing several ns RF pulses with peak power from 50 to 700 MW (6% standard deviation) at frequencies from 0.5 to 1.7 GHz (1% standard deviation) with 100 Hz repetition rate. Using a helix antenna allows irradiating of RF pulses with almost circular polarization and 350 MW maximum peak power, which corresponds to 350 kV effective potential of radiation. At the installation of two identical channels, we demonstrate the possibility of beam steering within ±15° in the horizontal plane by coherent RF pulses with circular polarization at 1.0 GHz center frequency. Fourfold increase in the power flux density for in-phase irradiation of RF pulses is confirmed by comparison with one-channel operation.

  19. RF Input Power Couplers for High Current SRF Applications

    SciTech Connect

    Khan, V. F.; Anders, W.; Burrill, Andrew; Knobloch, Jens; Kugeler, Oliver; Neumann, Axel; Wang, Haipeng

    2014-12-01

    High current SRF technology is being explored in present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input RF power required for the photo-injector as well as booster cavities where there is no energy recovery process. A high power co-axial input power coupler is being developed to be used for the photo-injector and booster cavities at the nominal beam current. The coupler is based on the KEK–cERL design and has been modified to minimise the penetration of the coupler tip in the beam pipe without compromising on beam-power coupling (Qext ~105). Herein we report on the RF design of the high power (115 kW per coupler, dual couplers per cavity) bERLinPro (BP) coupler along with initial results on thermal calculations. We summarise the RF conditioning of the TTF-III couplers (modified for cw operation) performed in the past at BESSY/HZB. A similar conditioning is envisaged in the near future for the low current SRF photo-injector and the bERLinPro main linac cryomodule.

  20. All-metal metamaterial slow-wave structure for high-power sources with high efficiency

    NASA Astrophysics Data System (ADS)

    Wang, Yanshuai; Duan, Zhaoyun; Tang, Xianfeng; Wang, Zhanliang; Zhang, Yabin; Feng, Jinjun; Gong, Yubin

    2015-10-01

    In this paper, we have proposed a metamaterial (MTM) which is suitable for the compact high-power vacuum electron devices. For example, an S-band slow-wave structure (SWS) based on the all-metal MTMs has been studied by both simulation and experiment. The results show that this MTM SWS is very helpful to miniaturize the high-power vacuum electron devices and largely improve the output power and the electronic efficiency. The simulation model of an S-band MTM backward wave oscillator (BWO) is built, and the particle-in-cell simulated results are presented here: a 2.454 GHz signal is generated and its peak output power is 4.0 MW with a higher electronic efficiency of 31.5% relative to the conventional BWOs.

  1. All-metal metamaterial slow-wave structure for high-power sources with high efficiency

    SciTech Connect

    Wang, Yanshuai; Duan, Zhaoyun Tang, Xianfeng; Wang, Zhanliang; Zhang, Yabin; Gong, Yubin; Feng, Jinjun

    2015-10-12

    In this paper, we have proposed a metamaterial (MTM) which is suitable for the compact high-power vacuum electron devices. For example, an S-band slow-wave structure (SWS) based on the all-metal MTMs has been studied by both simulation and experiment. The results show that this MTM SWS is very helpful to miniaturize the high-power vacuum electron devices and largely improve the output power and the electronic efficiency. The simulation model of an S-band MTM backward wave oscillator (BWO) is built, and the particle-in-cell simulated results are presented here: a 2.454 GHz signal is generated and its peak output power is 4.0 MW with a higher electronic efficiency of 31.5% relative to the conventional BWOs.

  2. High average power solid state laser power conditioning system

    SciTech Connect

    Steinkraus, R.F.

    1987-03-03

    The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers.

  3. High Power Free Electron Lasers

    SciTech Connect

    George Neil

    2004-04-12

    FEL Oscillators have been around since 1977 providing not only a test bed for the physics of Free Electron Lasers and electron/photon interactions but as a workhorse of scientific research. The characteristics that have driven the development of these sources are the desire for high peak and average power, high pulse energies, wavelength tunability, timing flexibility, and wavelengths that are unavailable from more conventional laser sources. User programs have been performed using such sources encompassing medicine, biology, solid state research, atomic and molecular physics, effects of non-linear fields, surface science, polymer science, pulsed laser vapor deposition, to name just a few. Recently the incorporation of energy recovery systems has permitted extension of the average power capabilities to the kW level and beyond. Development of substantially higher power systems with applications in defense and security is believed feasible with modest R&D efforts applied to a few technology areas. This paper will discuss at a summary level the physics of such devices, survey existing and planned facilities, and touch on the applications that have driven the development of these popular light sources.

  4. SEMICONDUCTOR INTEGRATED CIRCUITS: A 3.1-4.8 GHz transmitter with a high frequency divider in 0.18 μm CMOS for OFDM-UWB

    NASA Astrophysics Data System (ADS)

    Renliang, Zheng; Junyan, Ren; Wei, Li; Ning, Li

    2009-12-01

    A fully integrated low power RF transmitter for a WiMedia 3.1-4.8 GHz multiband orthogonal frequency division multiplexing ultra-wideband system is presented. With a separate transconductance stage, the quadrature up-conversion modulator achieves high linearity with low supply voltage. The co-design of different resonant frequencies of the modulator and the differential to single (D2S) converter ensures in-band gain flatness. By means of a series inductor peaking technique, the D2S converter obtains 9 dB more gain without extra power consumption. A divided-by-2 divider is used for carrier signal generation. The measurement results show an output power between -10.7 and -3.1 dBm with 7.6 dB control range, an OIP3 up to 12 dBm, a sideband rejection of 35 dBc and a carrier rejection of 30 dBc. The ESD protected chip is fabricated in the Jazz 0.18 μm RF CMOS process with an area of 1.74 mm2 and only consumes 32 mA current (at 1.8 V) including the test associated parts.

  5. Power combiner with high power capacity and high combination efficiency for two phase-locked relativistic backward wave oscillators

    NASA Astrophysics Data System (ADS)

    Xiao, Renzhen; Deng, Yuqun; Wang, Yue; Song, Zhimin; Li, Jiawei; Sun, Jun; Chen, Changhua

    2015-09-01

    To realize power combination of two phase-locked relativistic backward wave oscillators (RBWOs), a compact power combiner is designed and investigated by 3-D particle-in-cell (PIC) simulation and experiment. The power combiner consists of two TM01-TE11 serpentine mode converters with a common output. When the two incident ports are fed with TM01 modes with a relative phase of 180° and power of 2.5 GW at each port, the conversion efficiency from the incident TM01 modes to the combined TE11 mode is 95.2% at 9.3 GHz, and the maximum electric field in the combiner is 714 kV/cm. The PIC simulation shows that the output power from the common port is 4.2 GW when the power combiner is connected to the two RBWOs with input signals, both producing 2.2 GW microwave, corresponding to a combination efficiency of 95.4%. In the high power microwave test, a method is proposed to obtain the combination efficiency without breaking the vacuum, which is 94.1% when the two phase-locked RBWOs output 1.8 GW and 2.2 GW. The power capacity of multi-gigawatts has been demonstrated.

  6. High voltage DC power supply

    DOEpatents

    Droege, T.F.

    1989-12-19

    A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.

  7. High voltage DC power supply

    DOEpatents

    Droege, Thomas F.

    1989-01-01

    A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively.

  8. Time-reversal duality of high-efficiency RF power amplifiers

    SciTech Connect

    Reveyrand, T; Ramos, I; Popovic, Z

    2012-12-06

    The similarity between RF power amplifiers and rectifiers is discussed. It is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode. Nonlinear simulations with a GaN HEMT transistor model show the time-reversal intrinsic voltage and current waveform relationship between a class-F amplifier and rectifier. Measurements on a class-F-1 amplifier and rectifier at 2.14 GHz demonstrate over 80% efficiency in both cases.

  9. High power cladding light strippers

    NASA Astrophysics Data System (ADS)

    Wetter, Alexandre; Faucher, Mathieu; Sévigny, Benoit

    2008-02-01

    The ability to strip cladding light from double clad fiber (DCF) fibers is required for many different reasons, one example is to strip unwanted cladding light in fiber lasers and amplifiers. When removing residual pump light for example, this light is characterized by a large numerical aperture distribution and can reach power levels into the hundreds of watts. By locally changing the numerical aperture (N.A.) of the light to be stripped, it is possible to achieve significant attenuation even for the low N.A. rays such as escaped core modes in the same device. In order to test the power-handling capability of this device, one hundred watts of pump and signal light is launched from a tapered fusedbundle (TFB) 6+1x1 combiner into a high power-cladding stripper. In this case, the fiber used in the cladding stripper and the output fiber of the TFB was a 20/400 0.06/0.46 N.A. double clad fiber. Attenuation of over 20dB in the cladding was measured without signal loss. By spreading out the heat load generated by the unwanted light that is stripped, the package remained safely below the maximum operating temperature internally and externally. This is achieved by uniformly stripping the energy along the length of the fiber within the stripper. Different adhesive and heat sinking techniques are used to achieve this uniform removal of the light. This suggests that these cladding strippers can be used to strip hundreds of watts of light in high power fiber lasers and amplifiers.

  10. High resolution interferometric observations of the solar limb at 4.9 and 10.7 GHz during the solar eclipse of October, 1977

    NASA Technical Reports Server (NTRS)

    Marsh, K. A.; Hurford, G. J.; Zirin, H.

    1981-01-01

    The radial intensity profile of the quiet solar limb has been measured at high spatial resolution using the VLA at 4.9 GHz and the Owens Valley solar interferometer at 10.7 GHz during the partial solar eclipse of October 12, 1977. The spatial resolution (13.8 arcsec at 4.9 GHz and 7.4 arcsec at 10.7 GHz) was provided primarily by the lunar limb. Substantial limb brightening at 4.9 GHz was found with a peak brightness temperature corresponding to an 80% increase over the disk value, and a possible small limb enhancement at 10.7 GHz. The results are consistent with a simple model consisting of a uniform disk (provided by a thoroughly roughened transition zone) overlaid by a corona in hydrostatic equilibrium with a density of 5 x 10 to the 8th at its base. The lack of the secant-like variation in the microwave intensity from center to limb is explained by a corona contained in loop structures rather than in spherically symmetric layers.

  11. Development of a High Resolution Passive Microwave 3U Cubesat for High Resolution Temperature Sounding and Imaging at 118 GHz

    NASA Astrophysics Data System (ADS)

    Gasiewski, A. J.; Sanders, B. T.; Gallaher, D. W.; Periasamy, L.; Alvarenga, G.; Weaver, R.; Scambos, T. A.

    2014-12-01

    PolarCube is a 3U CubeSat based on the CU ALL-STAR bus hosting an eight-channel passive microwave scanning spectrometer operating at the 118.7503 GHz (1-) O2 resonance. The anticipated launch date is in late 2015. It is being designed to operate for 12 months on orbit to provide global 118-GHz spectral imagery of the Earth over a full seasonal cycle. The mission will focus on the study of Arctic vertical temperature structure and its relation to sea ice coverage, but include the secondary goals of assessing the potential for convective cloud mass detection and cloud top altitude measurement and hurricane warm core sounding. The principles used by PolarCube for sounding and cloud measurement have been well established in number of peer-reviewed papers, although measurements using the 118 GHz oxygen line over the dry polar regions (unaffected by water vapor) have never been demonstrated from space. The PolarCube channels are selected to probe clear-air emission over vertical levels from the surface to the lower stratosphere. Operational spaceborne microwave soundings have available for decades but using lower frequencies (50-57 GHz) and from higher altitudes. While the JPSS ATMS sensor provides global coverage at ~32 km resolution PolarCube will improve on this resolution by a factor of two (~16 km), thus facilitating a key science goal of mapping sea ice concentration and extent while obtaining temperature profile data. Additionally, we seek to correlate freeze-thaw line data from the NASA SMAP mission with atmospheric temperature structure to help understand the relationship between clouds, temperature, and surface energy fluxes during seasonal transitions. PolarCube will also provide the first demonstration of a very low cost passive microwave sounder that if operated in a fleet configuration would have the potential to fulfill the goals of the Precipitation Atmospheric Temperature and Humidity (PATH) mission, as defined in the NRC Decadal Survey.

  12. High quality factor manganese-doped aluminum lumped-element kinetic inductance detectors sensitive to frequencies below 100 GHz

    NASA Astrophysics Data System (ADS)

    Jones, G.; Johnson, B. R.; Abitbol, M. H.; Ade, P. A. R.; Bryan, S.; Cho, H.-M.; Day, P.; Flanigan, D.; Irwin, K. D.; Li, D.; Mauskopf, P.; McCarrick, H.; Miller, A.; Song, Y. R.; Tucker, C.

    2017-05-01

    Aluminum lumped-element kinetic inductance detectors (LEKIDs) sensitive to millimeter-wave photons have been shown to exhibit high quality factors, making them highly sensitive and multiplexable. The superconducting gap of aluminum limits aluminum LEKIDs to photon frequencies above 100 GHz. Manganese-doped aluminum (Al-Mn) has a tunable critical temperature and could therefore be an attractive material for LEKIDs sensitive to frequencies below 100 GHz if the internal quality factor remains sufficiently high when manganese is added to the film. To investigate, we measured some of the key properties of Al-Mn LEKIDs. A prototype eight-element LEKID array was fabricated using a 40 nm thick film of Al-Mn deposited on a 500 μm thick high-resistivity, float-zone silicon substrate. The manganese content was 900 ppm, the measured Tc = 694 ± 1mK, and the resonance frequencies were near 150 MHz. Using measurements of the forward scattering parameter S21 at various bath temperatures between 65 and 250 mK, we determined that the Al-Mn LEKIDs we fabricated have internal quality factors greater than 2 × 105, which is high enough for millimeter-wave astrophysical observations. In the dark conditions under which these devices were measured, the fractional frequency noise spectrum shows a shallow slope that depends on bath temperature and probe tone amplitude, which could be two-level system noise. The anticipated white photon noise should dominate this level of low-frequency noise when the detectors are illuminated with millimeter-waves in future measurements. The LEKIDs responded to light pulses from a 1550 nm light-emitting diode, and we used these light pulses to determine that the quasiparticle lifetime is 60 μs.

  13. High quality factor manganese-doped aluminum lumped-element kinetic inductance detectors sensitive to frequencies below 100 GHz

    DOE PAGES

    Jones, G.; Johnson, B. R.; Abitbol, M. H.; ...

    2017-05-29

    Aluminum lumped-element kinetic inductance detectors (LEKIDs) sensitive to millimeter-wave photons have been shown to exhibit high quality factors, making them highly sensitive and multiplexable. The superconducting gap of aluminum limits aluminum LEKIDs to photon frequencies above 100 GHz. Manganese-doped aluminum (Al-Mn) has a tunable critical temperature and could therefore be an attractive material for LEKIDs sensitive to frequencies below 100 GHz if the internal quality factor remains sufficiently high when manganese is added to the film. To investigate, we measured some of the key properties of Al-Mn LEKIDs. A prototype eight-element LEKID array was fabricated using a 40 nm thickmore » film of Al-Mn deposited on a 500 μm thick high-resistivity, float-zone silicon substrate. The manganese content was 900 ppm, the measured Tc = 694 ± 1mK, and the resonance frequencies were near 150 MHz. Using measurements of the forward scattering parameter S21 at various bath temperatures between 65 and 250 mK, we determined that the Al-Mn LEKIDs we fabricated have internal quality factors greater than 2 × 105, which is high enough for millimeter-wave astrophysical observations. In the dark conditions under which these devices were measured, the fractional frequency noise spectrum shows a shallow slope that depends on bath temperature and probe tone amplitude, which could be two-level system noise. In conclusion, the anticipated white photon noise should dominate this level of low-frequency noise when the detectors are illuminated with millimeter-waves in future measurements. The LEKIDs responded to light pulses from a 1550 nm light-emitting diode, and we used these light pulses to determine that the quasiparticle lifetime is 60 μs.« less

  14. HIGH-POWER RF DISTRIBUTION SYSTEMFOR THE 8-PACK PROJECT

    SciTech Connect

    Nantista, C

    2004-08-24

    The 8-Pack Project at SLAC is a prototype rf system whose goal is to demonstrate the high-power X-band technology developed in the NLC/GLC (Next/Global Linear Collider) program. In its first phase, it has reliably produced a 400 ns rf pulse of over 500 MW using a solidstate modulator, four 11.424 GHz klystrons and a dualmoded SLED-II pulse compressor. In Phase 2, the output power of the system has been delivered into the bunker of the NLCTA (Next Linear Collider Test Accelerator) and divided between several accelerator structures for beam acceleration. The authors describe here the design, cold-test measurements, and processing of this power distribution system. Due to the high power levels and the need for efficiency, overmoded waveguide and components are used. For power transport, the TE{sub 01} mode is used in 7.44 cm and 4.064 cm diameter circular waveguide. Only near the structures is standard WR90 rectangular waveguide employed. Components used to manipulate the rf power include transitional tapers, mode converters, overmoded bends, fractional directional couplers, and hybrids.

  15. High Power Helicon Propulsion Experiments

    NASA Astrophysics Data System (ADS)

    Ziemba, Timothy; Slough, John; Winglee, Robert

    2005-02-01

    The High Power Helicon (HPH) under development at the University of Washington may have an attractive application as an electrode-less in-space thruster. Output plasma characteristics show that plasma is created in and near the helicon coil and is accelerated by a helicon induced axial potential downstream away from the HPH. The bulk acceleration of the plasma is believed to be due to a coupling of the plasma electrons to the helicon field, which in turn transfers energy to the ions via an ambipolar electric field. Downstream electric potentials of greater than 150 volts having been measured with the amplitude of the electric field being dependent on experimentally controlled parameters. Time of flight measurements of the plasma transiting downstream show specific impulses (Isp) near 2000 seconds for Argon with calculated thrust levels near 1 Newton for input powers to the plasma in the tens of kilowatts. The system is capable of using different neutral gases as propellants with nitrogen and hydrogen having baseline Isp levels of 3000 and 5000 seconds respectfully giving some variability in Isp and thrust by the choice of propellants. Current work focuses on the determination and optimization of the system efficiencies and increasing output power levels.

  16. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  17. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, Lloyd A.; Dane, Clifford B.

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  18. High-power pulsed lasers

    SciTech Connect

    Holzrichter, J.F.

    1980-04-02

    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization.

  19. Improved Programmable High-Voltage Power Supply

    NASA Technical Reports Server (NTRS)

    Castell, Karen; Rutberg, Arthur

    1994-01-01

    Improved dc-to-dc converter functions as programmable high-voltage power supply with low-power-dissipation voltage regulator on high-voltage side. Design of power supply overcomes deficiencies of older designs. Voltage regulation with low power dissipation provided on high-voltage side.

  20. Integrated 1.55 µm photomixer local oscillator sources for heterodyne receivers from 70 GHz to beyond 250 GHz

    NASA Astrophysics Data System (ADS)

    Huggard, Peter G.; Azcona, Luis; Laisné, Alexandre; Ellison, Brian N.; Shen, Pengbo; Gomes, Nathan J.; Davies, Phil A.

    2004-10-01

    Photomixing is a flexible and efficient method of providing both local oscillator signals for heterodyne receivers and high frequency phase reference signals. Ultrafast, 70 GHz bandwidth, λ = 1.55 µm, photodiodes from u2t Photonics AG have been incorporated into three designs of mm-wave waveguide mounts. The photomixers utilise a thin freestanding gold foil, or a gold on dielectric, probe to couple power into the waveguide and to deliver the photodiode bias. The frequency coverage of the designs is from 70 GHz to 300 GHz. A method of rapidly characterizing the frequency response of these photomixers using spontaneous-spontaneous beating of light from an EDFA is described. Recent work has been directed at increasing the degree of integration of the photodiode with the waveguide probe and choke filter to reduce the frequency dependence of the output power. A simplified photomixer block manufacturing process has also been introduced. A combined probe and filter structure, impedance matched to both the coplanar output line on the photodiode chip and to 0.4 height milled waveguide, is presented. This matching is achieved over the W-band with a fixed waveguide backshort. We present modelled and experimental results showing the increased efficiency and smoother tuning. The design and frequency response of such a probe is reported. We also present the performance of a simpler mount, operating in the frequency range from 160 GHz to 300 GHz, which generates powers of around 10 µW up to 250 GHz.

  1. High speed, high power one-dimensional beam steering from a 6-element optical phased array.

    PubMed

    Huang, W Ronny; Montoya, Juan; Kansky, Jan E; Redmond, Shawn M; Turner, George W; Sanchez-Rubio, Antonio

    2012-07-30

    Beam steering at high speed and high power is demonstrated from a 6-element optical phased array using coherent beam combining (CBC) techniques. The steering speed, defined as the inverse of the time to required to sweep the beam across the steering range, is 40 MHz and the total power is 396 mW. The measured central lobe FWHM width is 565 μrad. High on-axis intensity is maintained periodically by phase-locking the array via a stochastic-parallel-gradient-descent (SPGD) algorithm. A master-oscillator-power-amplifier (MOPA) configuration is used where the amplifier array elements are semiconductor slab-coupled-optical-waveguide-amplifiers (SCOWAs). The beam steering is achieved by LiNbO(3) phase modulators; the phase-locking occurs by current adjustment of the SCOWAs. The system can be readily scaled to GHz steering speed and multiwatt-class output.

  2. Fabrication and materials for magneto-photonic assemblies for high-gain antenna applications at GHz frequencies

    NASA Astrophysics Data System (ADS)

    Zhang, Lanlin

    Recent magnetic photonic assembly (MPA) designs for high-gain antennas contain arrays of low-loss, anisotropic dielectrics and ferrimagnetic materials. Anisotropic dielectrics (AD) are fabricated from laminates, which consist of two ceramics with largely different permittivity and low dielectric losses at GHz frequencies. High gain has been demonstrated in a prototype antenna with 2 sets of 3 mutually rotated AD layers. These layers were made from laminates of commercially available alpha-Al2O3 and Nd-doped barium titanate. Equivalent permittivity tensors and loss tangents (tan delta˜1.9x10-3) were characterized using a resonant cavity based approach, coupled with a finite-element method (FEM) full-wave solver. To enable further minimization of dielectric loss (tan delta), dense high-purity alpha-Al2O3 and TiO2 were prepared starting from colloidally stabilizing the powders in aqueous HNO3 or NH3. After colloidal filtration and sintering, alpha-Al 2O3 with >97.9% density was achieved at a sintering temperature of 1300°C, and TiO2 with >99.5% density was obtained at 1000°C. These low sintering temperatures are ascribed to excellent compact homogeneity. TiO2 was obtained with tan delta of 1.4x10-4 at 6.4 GHz at room temperature. This relatively low value is attributed to the homogeneous dense microstructure with 2.2 mum grain size. Al 3+ was doped into TiO2 using a modified infiltration method to compensate for the effect of Ti4+ reduction. A homogeneous microstructure and doping concentration were also observed in the doped dense TiO2. Substituted Y3Fe5O12 (YIG) garnet was chosen as the ferrimagnetic (F) component, due to its pronounced Faraday rotation effect and potentially low magnetic and dielectric loss. Phase pure garnet was prepared by using the citric-gel method. The magnetic properties were studied for Ca,V,Zr-substituted YIG (CVZG) and as-prepared particle morphology. Compacts of CVZG submicron particles were found to possess a low loss at GHz

  3. High frequency, high power capacitor development

    NASA Technical Reports Server (NTRS)

    White, C. W.; Hoffman, P. S.

    1983-01-01

    A program to develop a special high energy density, high power transfer capacitor to operate at frequency of 40 kHz, 600 V rms at 125 A rms plus 600 V dc bias for space operation. The program included material evaluation and selection, a capacitor design was prepared, a thermal analysis performed on the design. Fifty capacitors were manufactured for testing at 10 kHz and 40 kHz for 50 hours at Industrial Electric Heating Co. of Columbus, Ohio. The vacuum endurance test used on environmental chamber and temperature plate furnished by Maxwell. The capacitors were energized with a special power conditioning apparatus developed by Industrial Electric Heating Co. Temperature conditions of the capacitors were monitored by IEHCo test equipment. Successful completion of the vacuum endurance test series confirmed achievement of the main goal of producing a capacitor or reliable operation at high frequency in an environment normally not hospitable to electrical and electronic components. The capacitor developed compared to a typical commercial capacitor at the 40 kHz level represents a decrease in size and weight by a factor of seven.

  4. High frequency, high power capacitor development

    NASA Astrophysics Data System (ADS)

    White, C. W.; Hoffman, P. S.

    1983-03-01

    A program to develop a special high energy density, high power transfer capacitor to operate at frequency of 40 kHz, 600 V rms at 125 A rms plus 600 V dc bias for space operation. The program included material evaluation and selection, a capacitor design was prepared, a thermal analysis performed on the design. Fifty capacitors were manufactured for testing at 10 kHz and 40 kHz for 50 hours at Industrial Electric Heating Co. of Columbus, Ohio. The vacuum endurance test used on environmental chamber and temperature plate furnished by Maxwell. The capacitors were energized with a special power conditioning apparatus developed by Industrial Electric Heating Co. Temperature conditions of the capacitors were monitored by IEHCo test equipment. Successful completion of the vacuum endurance test series confirmed achievement of the main goal of producing a capacitor or reliable operation at high frequency in an environment normally not hospitable to electrical and electronic components. The capacitor developed compared to a typical commercial capacitor at the 40 kHz level represents a decrease in size and weight by a factor of seven.

  5. High power, high frequency, vacuum flange

    DOEpatents

    Felker, Brian; McDaniel, Michael R.

    1993-01-01

    An improved waveguide flange is disclosed for high power operation that helps prevent arcs from being initiated at the junctions between waveguide sections. The flanges at the end of the waveguide sections have counterbores surrounding the waveguide tubes. When the sections are bolted together the counterbores form a groove that holds a fully annealed copper gasket. Each counterbore has a beveled step that is specially configured to insure the gasket forms a metal-to-metal vacuum seal without gaps or sharp edges. The resultant inner surface of the waveguide is smooth across the junctions between waveguide sections, and arcing is prevented.

  6. High Power, High Voltage Electric Power System for Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Aintablian, Harry; Kirkham, Harold; Timmerman, Paul

    2006-01-01

    This paper provides an overview of the 30 KW, 600 V MRHE power subsystem. Descriptions of the power subsystem elements, the mode of power transfer, and power and mass estimates are presented. A direct-drive architecture for electric propulsion is considered which reduces mass and complexity. Solar arrays with concentrators are used for increased efficiency. Finally, the challenges due to the environment of a hypothetical lunar mission as well as due to the advanced technologies considered are outlined.

  7. High-power microwave transmission and launching systems for fusion plasma heating systems

    SciTech Connect

    Bigelow, T.S.

    1989-01-01

    Microwave power in the 30- to 300-GHz frequency range is becoming widely used for heating of plasma in present-day fusion energy magnetic confinement experiments. Microwave power is effective in ionizing plasma and heating electrons through the electron cyclotron heating (ECH) process. Since the power is absorbed in regions of the magnetic field where resonance occurs and launching antennas with narrow beam widths are possible, power deposition location can be highly controlled. This is important for maximizing the power utilization efficiency and improving plasma parameters. Development of the gyrotron oscillator tube has advanced in recent years so that a 1-MW continuous-wave, 140-GHz power source will soon be available. Gyrotron output power is typically in a circular waveguide propagating a circular electric mode (such as TE/sub 0,2/) or a whispering-gallery mode (such as TE/sub 15,2/), depending on frequency and power level. An alternative high-power microwave source currently under development is the free-electron laser (FEL), which may be capable of generating 2-10 MW of average power at frequencies of up to 500 GHz. The FEL has a rectangular output waveguide carrying the TE/sub 0,1/ mode. Because of its higher complexity and cost, the high-average-power FEL is not yet as extensively developed as the gyrotron. In this paper, several types of operating ECH transmission systems are discussed, as well systems currently being developed. The trend in this area is toward higher power and frequency due to the improvements in plasma density and temperature possible. Every system requires a variety of components, such as mode converters, waveguide bends, launchers, and directional couplers. Some of these components are discussed here, along with ongoing work to improve their performance. 8 refs.

  8. A high-efficiency tunable TEM-TE11 mode converter for high-power microwave applications

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Yu; Fan, Yu-Wei; Shu, Ting; Yuan, Cheng-wei; Zhang, Qiang

    2017-03-01

    The tunable high power microwave source (HPM's) is considered to be an important research direction. However, the corresponding mode converter has been researched little. In this paper, a high-efficiency tunable mode converter (HETMC) is investigated for high-power microwave applications. The HETMC that is consisted of coaxial inner and outer conductors, with four metal plates arranged radially, at 90° in the coaxial gap, and matching rods can transform coaxial transverse electromagnetic (TEM) mode to TE11 coaxial waveguide mode. The results show that adjusting the length of the downstream plate, and the distance between the rods installed upstream and the closest edges of the plates, can improve the conversion efficiency and bandwidth remarkably. Moreover, when the frequency ranges from 1.63 GHz to 2.12 GHz, the conversion efficiency is above 95% between 1.63 GHz and 2.12 GHz with a bandwidth of 26.1%. Besides, the unwished reflection and transmission can be eliminated effectively in the HETMC.

  9. Measurement of the dielectric properties of high-purity sapphire at 1.865 GHZ from 2-10 Kelvin

    SciTech Connect

    N. Pogue, P. McIntyre, Akhdiyor Sattarov, Charles Reece

    2012-06-01

    A dielectric test cavity was designed and tested to measure the microwave dielectric properties of ultrapure sapphire at cryogenic temperatures. Measurements were performed by placing a large cylindrical crystal of sapphire in a Nb superconducting cavity operating in the TE01 mode at 1.865 GHz. The dielectric constant, heat capacity, and loss tangent were all calculated using experimental data and RF modeling software. The motivation for these measurements was to determine if such a sapphire could be used as a dielectric lens to focus the magnetic field onto a sample wafer in a high field wafer test cavity. The measured properties have been used to finalize the design of the wafer test cavity.

  10. HIGH-TIME-RESOLUTION MEASUREMENTS OF THE POLARIZATION OF THE CRAB PULSAR AT 1.38 GHz

    SciTech Connect

    Słowikowska, Agnieszka; Stappers, Benjamin W.; Harding, Alice K.; O'Dell, Stephen L.; Elsner, Ronald F.; Weisskopf, Martin C.; Van der Horst, Alexander J.

    2015-01-20

    Using the Westerbork Synthesis Radio Telescope, we obtained high-time-resolution measurements of the full polarization of the Crab pulsar. At a resolution of 1/8192 of the 34 ms pulse period (i.e., 4.1 μs), the 1.38 GHz linear-polarization measurements are in general agreement with previous lower-time-resolution 1.4 GHz measurements of linear polarization in the main pulse (MP), in the interpulse (IP), and in the low-frequency component (LFC). We find the MP and IP to be linearly polarized at about 24% and 21% with no discernible difference in polarization position angle. However, contrary to theoretical expectations and measurements in the visible, we find no evidence for significant variation (sweep) in the polarization position angle over the MP, the IP, or the LFC. We discuss the implications, which appear to be in contradiction to theoretical expectations. We also detect weak circular polarization in the MP and IP, and strong (≈20%) circular polarization in the LFC, which also exhibits very strong (≈98%) linear polarization at a position angle of 40° from that of the MP or IP. The properties are consistent with the LFC, which is a low-altitude component, and the MP and IP, which are high-altitude caustic components. Current models for the MP and IP emission do not readily account for the absence of pronounced polarization changes across the pulse. We measure IP and LFC pulse phases relative to the MP consistent with recent measurements, which have shown that the phases of these pulse components are evolving with time.

  11. Optical properties of high-frequency radio sources from the Australia Telescope 20 GHz (AT20G) Survey

    NASA Astrophysics Data System (ADS)

    Mahony, Elizabeth K.; Sadler, Elaine M.; Croom, Scott M.; Ekers, Ronald D.; Bannister, Keith W.; Chhetri, Rajan; Hancock, Paul J.; Johnston, Helen M.; Massardi, Marcella; Murphy, Tara

    2011-11-01

    Our current understanding of radio-loud active galactic nuclei (AGN) comes predominantly from studies at frequencies of 5 GHz and below. With the recent completion of the Australia Telescope 20 GHz (AT20G) survey, we can now gain insight into the high-frequency radio properties of AGN. This paper presents supplementary information on the AT20G sources in the form of optical counterparts and redshifts. Optical counterparts were identified using the SuperCOSMOS data base and redshifts were found from either the 6dF Galaxy Survey or the literature. We also report 144 new redshifts. For AT20G sources outside the Galactic plane, 78.5 per cent have optical identifications and 30.9 per cent have redshift information. The optical identification rate also increases with increasing flux density. Targets which had optical spectra available were examined to obtain a spectral classification. There appear to be two distinct AT20G populations; the high luminosity quasars that are generally associated with point-source optical counterparts and exhibit strong emission lines in the optical spectrum, and the lower luminosity radio galaxies that are generally associated with passive galaxies in both the optical images and spectroscopic properties. It is suggested that these different populations can be associated with different accretion modes (cold-mode or hot-mode). We find that the cold-mode sources have a steeper spectral index and produce more luminous radio lobes, but generally reside in smaller host galaxies than their hot-mode counterparts. This can be attributed to the fact that they are accreting material more efficiently. Lastly, we compare the AT20G survey with the S-cubed semi-empirical (S3-SEX) models and conclude that the S3-SEX models need refining to correctly model the compact cores of AGN. The AT20G survey provides the ideal sample to do this.

  12. High-time-resolution Measurements of the Polarization of the Crab Pulsar at 1.38 GHz

    NASA Astrophysics Data System (ADS)

    Słowikowska, Agnieszka; Stappers, Benjamin W.; Harding, Alice K.; O'Dell, Stephen L.; Elsner, Ronald F.; van der Horst, Alexander J.; Weisskopf, Martin C.

    2015-01-01

    Using the Westerbork Synthesis Radio Telescope, we obtained high-time-resolution measurements of the full polarization of the Crab pulsar. At a resolution of 1/8192 of the 34 ms pulse period (i.e., 4.1 μs), the 1.38 GHz linear-polarization measurements are in general agreement with previous lower-time-resolution 1.4 GHz measurements of linear polarization in the main pulse (MP), in the interpulse (IP), and in the low-frequency component (LFC). We find the MP and IP to be linearly polarized at about 24% and 21% with no discernible difference in polarization position angle. However, contrary to theoretical expectations and measurements in the visible, we find no evidence for significant variation (sweep) in the polarization position angle over the MP, the IP, or the LFC. We discuss the implications, which appear to be in contradiction to theoretical expectations. We also detect weak circular polarization in the MP and IP, and strong (≈20%) circular polarization in the LFC, which also exhibits very strong (≈98%) linear polarization at a position angle of 40° from that of the MP or IP. The properties are consistent with the LFC, which is a low-altitude component, and the MP and IP, which are high-altitude caustic components. Current models for the MP and IP emission do not readily account for the absence of pronounced polarization changes across the pulse. We measure IP and LFC pulse phases relative to the MP consistent with recent measurements, which have shown that the phases of these pulse components are evolving with time.

  13. Application of high power lasers to space power and propulsion

    NASA Technical Reports Server (NTRS)

    Nored, D. L.

    1976-01-01

    The transmission of laser power over long distances for applications such as direct conversion to propulsive thrust or electrical power is considered. Factors discussed include: problems inherent in transmitting, propagating, and receiving the laser beam over long ranges; high efficiency, closed-cycle, continuous wave operation; advancement of CO2 laser technology; and compatibility with photovoltaic power conversion devices.

  14. Automated Microwave Complex on the Basis of a Continuous-Wave Gyrotron with an Operating Frequency of 263 GHz and an Output Power of 1 kW

    NASA Astrophysics Data System (ADS)

    Glyavin, M. Yu.; Morozkin, M. V.; Tsvetkov, A. I.; Lubyako, L. V.; Golubiatnikov, G. Yu.; Kuftin, A. N.; Zapevalov, V. E.; V. Kholoptsev, V.; Eremeev, A. G.; Sedov, A. S.; Malygin, V. I.; Chirkov, A. V.; Fokin, A. P.; Sokolov, E. V.; Denisov, G. G.

    2016-02-01

    We study experimentally the automated microwave complex for microwave spectroscopy and diagnostics of various media, which was developed at the Institute of Applied Physics of the Russian Academy of Sciences in cooperation with GYCOM Ltd. on the basis of a gyrotron with a frequency of 263 GHz and operated at the first gyrofrequency harmonic. In the process of the experiments, a controllable output power of 0 .1 -1 kW was achieved with an efficiency of up to 17 % in the continuous-wave generation regime. The measured radiation spectrum with a relative width of about 10 -6 and the frequency values measured at various parameters of the device are presented. The results of measuring the parameters of the wave beam, which was formed by a built-in quasioptical converter, as well as the data obtained by measuring the heat loss in the cavity and the vacuum output window are analyzed.

  15. High power thrust vector actuation

    NASA Astrophysics Data System (ADS)

    Kittock, M. J.

    1993-06-01

    Modern missile programs are frequently favoring electro-mechanical (EM) thrust vector actuation (TVA) over hydraulic for a variety of reasons. However, actuation system performance requirements are not relaxed for EM systems. Thus the development of EM systems with greater power output is required. The configuration of EM actuator studied consists of a DC brushless motor driving a spur gear train, which drives a ballscrew that converts rotary motion to rectilinear motion. This design produces an actuator with high levels of performance in a compact mechanical package. Design for manufacturability and assembly (DFMA) was part of the design process, resulting in an actuator that can be assembled easily and will operate reliably. This paper will discuss the mechanical details of the resultant actuator and report test results on a prototype derivative.

  16. High-throughput and low-latency 60GHz small-cell network architectures over radio-over-fiber technologies

    NASA Astrophysics Data System (ADS)

    Pleros, N.; Kalfas, G.; Mitsolidou, C.; Vagionas, C.; Tsiokos, D.; Miliou, A.

    2017-01-01

    Future broadband access networks in the 5G framework will need to be bilateral, exploiting both optical and wireless technologies. This paper deals with new approaches and synergies on radio-over-fiber (RoF) technologies and how those can be leveraged to seamlessly converge wireless technology for agility and mobility with passive optical networks (PON)-based backhauling. The proposed convergence paradigm is based upon a holistic network architecture mixing mm-wave wireless access with photonic integration, dynamic capacity allocation and network coding schemes to enable high bandwidth and low-latency fixed and 60GHz wireless personal area communications for gigabit rate per user, proposing and deploying on top a Medium-Transparent MAC (MT-MAC) protocol as a low-latency bandwidth allocation mechanism. We have evaluated alternative network topologies between the central office (CO) and the access point module (APM) for data rates up to 2.5 Gb/s and SC frequencies up to 60 GHz. Optical network coding is demonstrated for SCM-based signaling to enhance bandwidth utilization and facilitate optical-wireless convergence in 5G applications, reporting medium-transparent network coding directly at the physical layer between end-users communicating over a RoF infrastructure. Towards equipping the physical layer with the appropriate agility to support MT-MAC protocols, a monolithic InP-based Remote Antenna Unit optoelectronic PIC interface is shown that ensures control over the optical resource allocation assisting at the same time broadband wireless service. Finally, the MT-MAC protocol is analysed and simulation and analytical theoretical results are presented that are found to be in good agreement confirming latency values lower than 1msec for small- to mid-load conditions.

  17. A resistive-gate Al(0.3)Ga(0.7)As/GaAs 2DEG CCD with high charge-transfer efficiency at 1 GHz

    NASA Technical Reports Server (NTRS)

    Song, J.-I.; Rossi, D. V.; Xin, S.; Wang, W. I.; Fossum, E. R.

    1991-01-01

    The fabrication and performance of an Al(0.3)Ga(0.7)As/GaAs modulation-doped resistive-gate CCD are reported. The two-dimensional electron gas (2DEG) CCD, implemented as a 32-stage four-phase delay line, was tested at both low (1-13 MHz) and high (0.6-1.0 GHz) frequency. It exhibits a room-temperature charge-transfer efficiency (CTE) of better than 0.999 at clock frequencies from 10 MHz up to 1 GHz without a fat-zero signal and is limited by dark current below 10 MHz. The high-frequency test showed no CTE degradation up to 1-GHz operation. The CTE degraded at frequencies lower than approximately 5 MHz due to dark current. The charge-handling capability and minimum clock swing of the resistive-gate 2DEG CCD are calculated.

  18. A resistive-gate Al(0.3)Ga(0.7)As/GaAs 2DEG CCD with high charge-transfer efficiency at 1 GHz

    NASA Technical Reports Server (NTRS)

    Song, J.-I.; Rossi, D. V.; Xin, S.; Wang, W. I.; Fossum, E. R.

    1991-01-01

    The fabrication and performance of an Al(0.3)Ga(0.7)As/GaAs modulation-doped resistive-gate CCD are reported. The two-dimensional electron gas (2DEG) CCD, implemented as a 32-stage four-phase delay line, was tested at both low (1-13 MHz) and high (0.6-1.0 GHz) frequency. It exhibits a room-temperature charge-transfer efficiency (CTE) of better than 0.999 at clock frequencies from 10 MHz up to 1 GHz without a fat-zero signal and is limited by dark current below 10 MHz. The high-frequency test showed no CTE degradation up to 1-GHz operation. The CTE degraded at frequencies lower than approximately 5 MHz due to dark current. The charge-handling capability and minimum clock swing of the resistive-gate 2DEG CCD are calculated.

  19. A 2-GHz Low-Power Down-Conversion Mixer in 0.18-μm CMOS Technology

    NASA Astrophysics Data System (ADS)

    Chen, Jun-Da; Lin, Zhi-Ming; Row, Jeen-Sheen

    A low-voltage and low-power RF mixer for WCDMA applications is presented. The paper presents a novel topology mixer that leads to a better performance in terms of isolation and power consumption for low supply voltage. The measuring results of the proposed mixer achieve: 7dB power conversion gain, 10.4dB double side band (DSB) noise figure, -2dBm input third-order intercept point (IIP3), and the total dc power consumption of this mixer including output buffers is 2.2mW from a 1V supply voltage. The current output buffer is about 1.96mW, the excellent LO-RF, LO-IF and RF-IF isolation achieved up to 49dB, 39.5dB and 57.3dB, respectively.

  20. A 250 GHz Gyrotron with a 3 GHz Tuning Bandwidth for Dynamic Nuclear Polarization

    PubMed Central

    Barnes, Alexander B.; Nanni, Emilio A.; Herzfeld, Judith; Griffin, Robert G.; Temkin, Richard J.

    2012-01-01

    We describe the design and implementation of a novel tunable 250 GHz gyrotron oscillator with >10 W output power over most of a 3 GHz band and >35 W peak power. The tuning bandwidth and power are sufficient to generate a >1 MHz nutation frequency across the entire nitroxide EPR lineshape for cross effect DNP, as well as to excite solid effect transitions utilizing other radicals, without the need for sweeping the NMR magnetic field. Substantially improved tunability is achieved by implementing a long (23 mm) interaction cavity that can excite higher order axial modes by changing either the magnetic field of the gyrotron or the cathode potential. This interaction cavity excites the rotating TE5,2,q mode, and an internal mode converter outputs a high-quality microwave beam with >94% Gaussian content. The gyrotron was integrated into a DNP spectrometer, resulting in a measured DNP enhancement of 54 on the membrane protein bacteriorhodopsin. PMID:22743211

  1. A 250 GHz gyrotron with a 3 GHz tuning bandwidth for dynamic nuclear polarization.

    PubMed

    Barnes, Alexander B; Nanni, Emilio A; Herzfeld, Judith; Griffin, Robert G; Temkin, Richard J

    2012-08-01

    We describe the design and implementation of a novel tunable 250 GHz gyrotron oscillator with >10 W output power over most of a 3 GHz band and >35 W peak power. The tuning bandwidth and power are sufficient to generate a >1 MHz nutation frequency across the entire nitroxide EPR lineshape for cross effect DNP, as well as to excite solid effect transitions utilizing other radicals, without the need for sweeping the NMR magnetic field. Substantially improved tunability is achieved by implementing a long (23 mm) interaction cavity that can excite higher order axial modes by changing either the magnetic field of the gyrotron or the cathode potential. This interaction cavity excites the rotating TE(₅,₂,q) mode, and an internal mode converter outputs a high-quality microwave beam with >94% Gaussian content. The gyrotron was integrated into a DNP spectrometer, resulting in a measured DNP enhancement of 54 on the membrane protein bacteriorhodopsin.

  2. A 250 GHz gyrotron with a 3 GHz tuning bandwidth for dynamic nuclear polarization

    NASA Astrophysics Data System (ADS)

    Barnes, Alexander B.; Nanni, Emilio A.; Herzfeld, Judith; Griffin, Robert G.; Temkin, Richard J.

    2012-08-01

    We describe the design and implementation of a novel tunable 250 GHz gyrotron oscillator with >10 W output power over most of a 3 GHz band and >35 W peak power. The tuning bandwidth and power are sufficient to generate a >1 MHz nutation frequency across the entire nitroxide EPR lineshape for cross effect DNP, as well as to excite solid effect transitions utilizing other radicals, without the need for sweeping the NMR magnetic field. Substantially improved tunability is achieved by implementing a long (23 mm) interaction cavity that can excite higher order axial modes by changing either the magnetic field of the gyrotron or the cathode potential. This interaction cavity excites the rotating TE5,2,q mode, and an internal mode converter outputs a high-quality microwave beam with >94% Gaussian content. The gyrotron was integrated into a DNP spectrometer, resulting in a measured DNP enhancement of 54 on the membrane protein bacteriorhodopsin.

  3. Detection of nanosecond-scale, high power THz pulses with a field effect transistor

    SciTech Connect

    Preu, S.; Lu, H.; Gossard, A. C.; Sherwin, M. S.

    2012-05-15

    We demonstrate detection and resolution of high power, 34 ns free electron laser pulses using a rectifying field effect transistor. The detector remains linear up to an input power of 11 {+-} 0.5 W at a pulse energy of 20 {+-} 1 {mu}J at 240 GHz. We compare its performance to a protected Schottky diode, finding a shorter intrinsic time constant. The damage threshold is estimated to be a few 100 W. The detector is, therefore, well-suited for characterizing high power THz pulses. We further demonstrate that the same detector can be used to detect low power continuous-wave THz signals with a post detection limited noise floor of 3.1 {mu}W/{radical}(Hz). Such ultrafast, high power detectors are important tools for high power and high energy THz facilities such as free electron lasers.

  4. High Power Intermodulation Measurements up to 30 W of High Temperature Superconducting Filters

    NASA Technical Reports Server (NTRS)

    Wilker, Charles; Carter, Charles F., III; Shen, Zhi-Yuan

    1999-01-01

    We have demonstrated a high power intermodulation measurement set-up capable of delivering 30 W in each of two fundamental tones. For closely spaced frequencies (less than 35 MHz), the dynamic range of the measurement is limited by the nonlinear performance of the mixer in the front end of the HP71210C spectrum analyzer. A tunable TE(sub 011) mode copper cavity was fabricated in which one of the endwalls could be adjusted shifting its resonant frequency between 5.7 and 6.6 GHz. Since the Q-value of this cavity is high, greater than 10(exp 4), and its bandwidth is small, less than 1 MHz, it can be used to attenuate the two fundamental tones relative to one of the harmonic tones, which greatly enhances the dynamic range of the measurement. This set-up can be used to measure the two-tone intermodulation distortion of any passive microwave device, e.g. a HTS filter, a connector, a cable, etc., over a frequency range of 5.9 to 6.4 GHz and a power range of 0.1 to 30 W. The third order intercept (TOI) of a prototype HTS filter measured at powers up to 30 W was +81.3 dBm.

  5. High power microwave source for a plasma wakefield experiment

    NASA Astrophysics Data System (ADS)

    Shafir, G.; Shlapakovski, A.; Siman-Tov, M.; Bliokh, Yu.; Leopold, J. G.; Gleizer, S.; Gad, R.; Rostov, V. V.; Krasik, Ya. E.

    2017-01-01

    The results of the generation of a high-power microwave (˜550 MW, 0.5 ns, ˜9.6 GHz) beam and feasibility of wakefield-excitation with this beam in under-dense plasma are presented. The microwave beam is generated by a backward wave oscillator (BWO) operating in the superradiance regime. The BWO is driven by a high-current electron beam (˜250 keV, ˜1.5 kA, ˜5 ns) propagating through a slow-wave structure in a guiding magnetic field of 2.5 T. The microwave beam is focused at the desired location by a dielectric lens. Experimentally obtained parameters of the microwave beam at its waist are used for numerical simulations, the results of which demonstrate the formation of a bubble in the plasma that has almost 100% electron density modulation and longitudinal and transverse electric fields of several kV/cm.

  6. High power laser apparatus and system

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Brandhorst, H. W., Jr. (Inventor)

    1975-01-01

    A high-power, continuous-wave laser was designed for use in power transmission and energy-collecting systems, and for producing incoherent light for pumping a laser material. The laser has a high repetitive pulsing rate per unit time, resulting in a high-power density beam. The laser is composed of xenon flash tubes powered by fast-charging capacitors flashed in succession by a high-speed motor connected to an automobile-type distributor.

  7. Optics assembly for high power laser tools

    DOEpatents

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  8. Electrode-plasma-driven radiation cutoff in long-pulse, high-power microwave devices

    SciTech Connect

    Rose, D. V.; Miller, C. L.; Welch, D. R.; Portillo, S.

    2013-03-15

    The impact of electrode plasma dynamics on the radiation production in a high power microwave device is examined using particle-in-cell simulations. Using the design of a compact 2.4 GHz magnetically insulated line oscillator (MILO) as the basis for numerical simulations, we characterize the time-dependent device power and radiation output over a range of cathode plasma formation rates. These numerical simulations can self-consistently produce radiation characteristics that are similar to measured signals in long pulse duration MILOs. This modeling capability should result in improved assessment of existing high-power microwave devices and lead to new designs for increased radiation pulse durations.

  9. Improving RF Transmit Power and Received Signal Strength in 2.4 GHz ZigBee Based Active RFID System with Embedded Method

    NASA Astrophysics Data System (ADS)

    Po'ad, F. A.; Ismail, W.; Jusoh, J. F.

    2017-08-01

    This paper describes the experiments and analysis conducted on 2.4 GHz embedded active Radio Frequency Identification (RFID) - Wireless Sensor Network (WSN) based system that has been developed for the purposes of location tracking and monitoring in indoor and outdoor environments. Several experiments are conducted to test the effectiveness and performance of the developed system and two of them is by measuring the Radio Frequency (RF) transmitting power and Received Signal Strength (RSS) to prove that the embedded active RFID tag is capable to generate higher transmit power during data transmission and able to provide better RSS reading compared to standalone RFID tag. Experiments are carried out on two RFID tags which are active RFID tag embedded with GPS and GSM (ER2G); and standalone RFID tag communicating with the same active RFID reader. The developed ER2G contributes 12.26 % transmit power and 6.47 % RSS reading higher than standalone RFID tag. The results conclude that the ER2G gives better performance compared to standalone RFID tag and can be used as guidelines for future design improvements.

  10. Design of a High Voltage Multi-Cavity 35 GHz Phase-Locked Gyrotron Oscillator

    DTIC Science & Technology

    1988-11-01

    Oak Ridge National Laboratory P.O. Box Y mail Stop 3 Building 9201 -2 Oak Ridge , Tennessee 37830 Attn: Dr. A. England 1 copy Office of...permeability, Y , is the rel3tivistic mass ratio of the beam prior to the interaction, r. is the cavity wall 4 radius, E is the peak electric field at the...o z0 >0) U CC I 4 >) 0 C 0 - 0 44~ L<L C/) 2 i 4 x cr. 4 LOp 4 L l 27 4a THRESHOLD E-BEAM POWER FOR BUNCHING CAVITY MODES

  11. Dielectric constant dispersion of yttrium-doped (Ba,Sr)TiO3 films in the high-frequency (10 kHz-67 GHz) domain

    NASA Astrophysics Data System (ADS)

    Jeong, Doo Seok; Hwang, Cheol Seong; Baniecki, J. D.; Shioga, T.; Kurihara, K.; Kamehara, N.; Ishii, M.

    2005-12-01

    The frequency dispersion of the dielectric constant of yttrium (Y)-doped (Ba,Sr)TiO3 thin films (Y-BST) in the high-frequency domain (10kHz-67GHz) was investigated. In order to remove the substantial parasitic capacitances, inductances, and resistances from the measured impedance data, test samples, short-circuit standard, and open-circuit standard structures were fabricated and their frequency response was measured. Before removing parasitic components, the measured dielectric response showed a rolloff at approximately 4GHz. However, after circuit calibration, the dielectric constant was almost constant up to 40GHz where another rolloff was observed. However, this rolloff was due to the uncompensated small parasitic components. Therefore, the dielectric constant of the Y-BST films (170 with a film thickness of 30nm) showed small frequency dispersion corresponding to the Curie-von Schweidler dispersion, of which the exponent is -0.0131, up to 40GHz. Furthermore, the decrease of the capacitance was 17% in the frequency range from 10kHzto40GHz.

  12. Perpendicularly magnetized YIG-film resonators and waveguides with high operating power

    NASA Astrophysics Data System (ADS)

    Balinskiy, M.; Mongolov, B.; Gutierrez, D.; Chiang, H.; Slavin, A.; Khitun, A.

    2017-05-01

    We propose a novel technique for building YIG film-based resonators and waveguides for high power operating microwave devices. Our approach is based on the effect of total internal reflection (TIR) at the interface between the non-metalized and metalized regions of YIG film, which take place for forward volume magnetostatic spin waves in perpendicularly magnetized YIG films. Prototype resonators and waveguides were designed, fabricated, and tested. The obtained experimental data demonstrate high quality factor of 50 dB and a high power operation up to +15 dBm in the frequency range from 1.8 GHz to 5.1 GHz. Application of such resonators and waveguides in electrically tunable microwave oscillators promises an extremely low phase noises about -135 dB/Hz at 10 kHz offset.

  13. Perpendicularly magnetized YIG-film resonators and waveguides with high operating power

    DOE PAGES

    Balinskiy, M.; Mongolov, B.; Gutierrez, D.; ...

    2016-12-27

    We propose a novel technique for building YIG film-based resonators and waveguides for high power operating microwave devices. Our approach is based on the effect of total internal reflection (TIR) at the interface between the non-metalized and metalized regions of YIG film, which take place for forward volume magnetostatic spin waves in perpendicularly magnetized YIG films. Prototype resonators and waveguides were designed, fabricated, and tested. The obtained experimental data demonstrate high quality factor of 50 dB and a high power operation up to +15 dBm in the frequency range from 1.8 GHz to 5.1 GHz. Application of such resonators andmore » waveguides in electrically tunable microwave oscillators promises an extremely low phase noises about - 135 dB/Hz at 10 kHz offset.« less

  14. Figures of merit in high-frequency and high-power GaN HEMTs

    NASA Astrophysics Data System (ADS)

    Marino, F. A.; Faralli, N.; Ferry, D. K.; Goodnick, S. M.; Saraniti, M.

    2009-11-01

    The most important metrics for the high-frequency and high-power performance of microwave transistors are the cut-off frequency fT, and the Johnson figure of merit FoMJohnson. We have simulated a state-of-the-art, high-frequency and high-power GaN HEMT using our full band Cellular Monte Carlo (CMC) simulator, in order to study the RF performance and compare different methods to obtain such metrics. The current gain as a function of the frequency, was so obtained both by the Fourier decomposition (FD) method and the analytical formula proposed by Akis. A cut-off frequency fT of 150 GHz was found in both the transit time analysis given by the analytical approach, and the transient Fourier analysis, which matches well with the 153 GHz value measured experimentally. Furthermore, through some physical considerations, we derived the relation between the FoMJohnson as a function of the breakdown voltage, VBD, and the cut-off frequency, fT . Using this relation and assuming a breakdown voltage of 80V as measured experimentally, a Johnson figure of merit of around 20 × 1012V/s was found for the HEMT device analyzed in this work.

  15. High-Power, High-Frequency Si-Based (SiGe) Transistors Developed

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.

    2002-01-01

    Future NASA, DOD, and commercial products will require electronic circuits that have greater functionality and versatility but occupy less space and cost less money to build and integrate than current products. System on a Chip (SOAC), a single semiconductor substrate containing circuits that perform many functions or containing an entire system, is widely recognized as the best technology for achieving low-cost, small-sized systems. Thus, a circuit technology is required that can gather, process, store, and transmit data or communications. Since silicon-integrated circuits are already used for data processing and storage and the infrastructure that supports silicon circuit fabrication is very large, it is sensible to develop communication circuits on silicon so that all the system functions can be integrated onto a single wafer. Until recently, silicon integrated circuits did not function well at the frequencies required for wireless or microwave communications, but with the introduction of small amounts of germanium into the silicon to make silicon-germanium (SiGe) transistors, silicon-based communication circuits are possible. Although microwavefrequency SiGe circuits have been demonstrated, there has been difficulty in obtaining the high power from their transistors that is required for the amplifiers of a transmitter, and many researchers have thought that this could not be done. The NASA Glenn Research Center and collaborators at the University of Michigan have developed SiGe transistors and amplifiers with state-of-the-art output power at microwave frequencies from 8 to 20 GHz. These transistors are fabricated using standard silicon processing and may be integrated with CMOS integrated circuits on a single chip. A scanning electron microscope image of a typical SiGe heterojunction bipolar transistor is shown in the preceding photomicrograph. This transistor achieved a record output power of 550 mW and an associated power-added efficiency of 33 percent at 8

  16. The Atacama Cosmology Telescope: A Measurement of the 600 less than l less than 8000 Cosmic Microwave Background Power Spectrum at 148 GHz

    NASA Technical Reports Server (NTRS)

    Fowler, J. W.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Bassistelli, E. S.; Bond, J. R.; Brown, B.; hide

    2010-01-01

    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1.4' angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg(sup 2) of the southern sky, in a 4 deg. 2-wide strip centered on declination 53 deg. South. The CMB at arc minute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy dusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 less than l less than 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 less than l less than 1150. The power beyond the Silk damping tail of the CMB (l approximately 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to sigma 8 = 0.8. We constrain the model's amplitude A(sub sz) less than 1.63 (95% CL). If interpreted as a measurement of as, this implies sigma (sup SZ) (sub 8) less than 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a 6-parameter ACDM model plus point sources and the SZ effect is consistent with these results.

  17. A high-power synthesized ultrawideband radiation source

    NASA Astrophysics Data System (ADS)

    Efremov, A. M.; Koshelev, V. I.; Plisko, V. V.; Sevostyanov, E. A.

    2017-09-01

    A high-power ultrawideband radiation source has been developed which is capable of synthesizing electromagnetic pulses with different frequency bands in free space. To this end, a new circuit design comprising a four-channel former of bipolar pulses of durations 2 and 3 ns has been elaborated and conditions for the stable operation of gas gaps of independent channels without external control pulses have been determined. Each element of the 2 × 2 array of combined antennas is driven from an individual channel of the pulse former. Antennas excited by pulses of the same duration are arranged diagonally. Two radiation synthesis modes have been examined: one aimed to attain ultimate field strength and the other aimed to attain an ultimate width of the radiation spectrum. The modes were changed by changing the time delay between the 2-ns and 3-ns pulses. For the first mode, radiation pulses with a frequency band of 0.2-0.8 GHz and an effective potential of 500 kV have been obtained. The synthesized radiation pulses produced in the second mode had an extended frequency band (0.1-1 GHz) and an effective potential of 220 kV. The pulse repetition frequency was 100 Hz.

  18. ULTRA HIGH POWER TRANSMISSION LINE TECHNIQUES

    DTIC Science & Technology

    The ultra-high power transmission line techniques including both failure mechanisms and component design are discussed. Failures resulting from...a waveguide. In view of the many advantages of the low loss mode in circular waveguide for ultra-high power levels, a mode transducer and a two...percent of the peak power of a standard rectangular wave guide. Water cooling is provided for high average power operation. Analysis of mode sup pression

  19. High-Speed Frequency Modulation of a 460-GHz Gyrotron for Enhancement of 700-MHz DNP-NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Idehara, T.; Khutoryan, E. M.; Tatematsu, Y.; Yamaguchi, Y.; Kuleshov, A. N.; Dumbrajs, O.; Matsuki, Y.; Fujiwara, T.

    2015-09-01

    The high-speed frequency modulation of a 460-GHz Gyrotron FU CW GVI (the official name in Osaka University is Gyrotron FU CW GOI) was achieved by modulation of acceleration voltage of beam electrons. The modulation speed f m can be increased up to 10 kHz without decreasing the modulation amplitude δ f of frequency. The amplitude δ f was increased almost linearly with the modulation amplitude of acceleration voltage Δ V a. At the Δ V a = 1 kV, frequency spectrum width df was 50 MHz in the case of f m < 10 kHz. The frequency modulation was observed as both the variation of the IF frequency in the heterodyne detection system measured by a high-speed oscilloscope and the widths of frequency spectra df measured on a frequency spectrum analyzer. Both results well agree reasonably. When f m exceeds 10 kHz, the amplitude δ f is decreased gradually with increasing f m because of the degradation of the used amplifier in response for high-speed modulation. The experiment was performed successfully for both a sinusoidal wave and triangle wave modulations. We can use the high-speed frequency modulation for increasing the enhancement factor of the dynamic nuclear polarization (DNP)-enhanced nuclear magnetic resonance (NMR) spectroscopy, which is one of effective and attractive methods for the high-frequency DNP-NMR spectroscopy, for example, at 700 MHz. Because the sensitivity of NMR is inversely proportional to the frequency, high-speed frequency modulation can compensate the decreasing the enhancement factor in the high-frequency DNP-NMR spectroscopy and keep the factor at high value. In addition, the high-speed frequency modulation is useful for frequency stabilization by a PID control of an acceleration voltage by feeding back of the fluctuation of frequency. The frequency stabilization in long time is also useful for application of a DNP-NMR spectroscopy to the analysis of complicated protein molecules.

  20. Development of high-power gyrotrons with gradually tapered cavity

    SciTech Connect

    Lei Chaojun; Yu Sheng; Niu Xinjian; Liu Yinghui; Li Hongfu; Li Xiang

    2012-12-15

    In high power gyrotrons, the parasitic modes coupled with the operating mode cannot be avoided in the beam-wave interaction. These parasitic modes will decrease the efficiency of the gyrotrons. The purity of the operating mode affected by different tapers should be carefully studied. The steady-state self-consistent nonlinear theory for gyrotron with gradually tapered cavity is developed in this paper. A steady-state calculation code including 'cold cavity' and 'hot cavity' is designed. By comparison, a time-domain model analysis of gyrotron operation is also studied by particle-in-cell (PIC). It is found that the tapers of gyrotron have different influences on the modes coupling between the operating mode and the parasitic modes. During the study, an example of 94 GHz gyrotron with pure operating mode TE{sub 03} has been designed. The purity of the operating mode in the optimized cavity is up to -77 dB, and in output waveguide of the cavity is up to -76 dB. At the same time, the beam-wave interaction in the designed cavity has been simulated, too. An output power of 120 kW, corresponding to 41.6% efficiency and an oscillation frequency of 94.099 GHz have been achieved with a 50 kV, 6 A helical electron beam at a guiding magnetic field of 3.5485 T. The results show that the power in spurious modes of the optimized cavity may be kept far below than that of the traditional tapered cavity.

  1. Small-signal analysis of ultra-high-speed 30 GHz VCSELs using an advanced multi-mode approach

    NASA Astrophysics Data System (ADS)

    Hamad, Wissam; Bou Sanayeh, Marwan; Hamad, Hassan; Hamad, Mustapha; Georges, Semaan; Hofmann, Werner

    2017-05-01

    Vertical-cavity surface-emitting lasers (VCSELs) have emerged as a pioneering solution for many high-speed data communication challenges. Therefore, higher bandwidth optical interconnects with data rates in the range of 100 Gbit/s require directly modulated VCSELs with ultimate speed ratings. The small-signal modulation response of a VCSEL can be isolated from the entire system, thus providing accurate information on the intrinsic laser dynamics. Until now, it is assumed that the dynamic behavior of oxide-confined multi-mode VCSELs can be fully modeled using the single-mode rate equations developed for edge-emitters, even though the deviation between the single-mode based model and the measured data is substantially large. Using an advanced theoretical approach, rate equations for multi-mode VCSELs were developed and the small-signal modulation response of ultra-high speed devices with split carrier reservoirs corresponding with the resonating modes were analyzed. Based on this theoretical work, and including gain compression in the model, the analyzed VCSELs showed modulation bandwidth around and exceeding 30 GHz. The common set of figures of merit is extended consistently to explain dynamic properties caused by the coupling of the different reservoirs. Furthermore, beside damping and relaxation oscillation frequency, the advanced model, with gain compression included, can reveal information on the photon lifetime and highlights high-speed effects such as reduced damping in VCSELs due to a negative gain compression factor.

  2. Simplified High-Power Inverter

    NASA Technical Reports Server (NTRS)

    Edwards, D. B.; Rippel, W. E.

    1984-01-01

    Solid-state inverter simplified by use of single gate-turnoff device (GTO) to commutate multiple silicon controlled rectifiers (SCR's). By eliminating conventional commutation circuitry, GTO reduces cost, size and weight. GTO commutation applicable to inverters of greater than 1-kilowatt capacity. Applications include emergency power, load leveling, drives for traction and stationary polyphase motors, and photovoltaic-power conditioning.

  3. Simplified High-Power Inverter

    NASA Technical Reports Server (NTRS)

    Edwards, D. B.; Rippel, W. E.

    1984-01-01

    Solid-state inverter simplified by use of single gate-turnoff device (GTO) to commutate multiple silicon controlled rectifiers (SCR's). By eliminating conventional commutation circuitry, GTO reduces cost, size and weight. GTO commutation applicable to inverters of greater than 1-kilowatt capacity. Applications include emergency power, load leveling, drives for traction and stationary polyphase motors, and photovoltaic-power conditioning.

  4. Q-Band (45 GHz) Microwave Integrated Circuit Power Amplifier Designs Submitted to TriQuint Semiconductor for Fabrication with 0.15-micron High-Electron-Mobility Transistors (HEMT) Using 2-mil Gallium Nitride (GaN) on Silicon Carbide (SiC)

    DTIC Science & Technology

    2013-09-01

    Electron-Mobility Transistors (HEMT) Using 2-mil Gallium Nitride (GaN) on Silicon Carbide (SiC) by John E. Penn ARL-TN-0574 September 2013...µm High-Electron-Mobility Transistors (HEMT) Using 2-mil Gallium Nitride (GaN) on Silicon Carbide (SiC) John E. Penn Sensors and Electron Devices...with 0.15-µm High- Electron-Mobility Transistors (HEMT) Using 2-mil Gallium Nitride (GaN) on Silicon Carbide (SiC) 5a. CONTRACT NUMBER 5b. GRANT

  5. A high declination search at 8 GHz for compact radio sources

    NASA Technical Reports Server (NTRS)

    Wittels, J. J.; Shapiro, I. I.; Robertson, D. S.; Hinteregger, H. F.; Knight, C. A.; Clark, T. A.; Hutton, L. K.; Ma, C.; Niell, A. E.; Resch, G. M.

    1978-01-01

    With the Haystack-NRAO interferometer (baseline length of 20 million wavelengths at 3.8 cm) 37 sources were observed whose declinations were above 50 deg. Seven of these sources have compact cores with diameters smaller than 5 milliarcsec and with correlated flux densities greater than about 0.5 Jy; the remaining sources have no cores with flux densities above about 0.3 Jy, the sensitivity limit of the interferometer. Two of the sources with detected compact cores, 4C 67.05 and 3C 418, were also observed with longer-baseline interferometers; the diameter of the core of 4C 67.05 was estimated to be smaller than 1 milliarcsec and that of 3C 418 to be smaller than 0.4 milliarcsec. All diameter estimates were based on an assumed circular Gaussian distribution of radio brightness and refer to the contour with brightness density e to the -1/2 power times that of the center. Positions for the detected sources were also obtained from the interferometric data, the uncertainty in these coordinate estimates ranging from 0.04 to 0.6 arcsec. The compact core detected in 3C 390.3 was found to lie near the center of this extended (approximately 4 arcmin in diameter) double radio source and to be coincident to within 1 arcsec with an N galaxy previously identified with 3C 390.3.

  6. 338-GHz Semiconductor Amplifier Module

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene A.; Gaier, Todd C.; Soria, Mary M.; Fung, King Man; Rasisic, Vesna; Deal, William; Leong, Kevin; Mei, Xiao Bing; Yoshida, Wayne; Liu, Po-Hsin; Uyeda, Jansen; Lai, Richard

    2010-01-01

    Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers.

  7. HIGH-RESOLUTION VERY LARGE ARRAY IMAGING OF SLOAN DIGITAL SKY SURVEY STRIPE 82 AT 1.4 GHz

    SciTech Connect

    Hodge, J. A.; Becker, R. H.; Zeimann, G. R.; White, R. L.; Richards, G. T.

    2011-07-15

    We present a high-resolution radio survey of the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, a.k.a. Stripe 82. This 1.4 GHz survey was conducted with the Very Large Array primarily in the A-configuration, with supplemental B-configuration data to increase sensitivity to extended structure. The survey has an angular resolution of 1.''8 and achieves a median rms noise of 52 {mu}Jy beam{sup -1} over 92 deg{sup 2}. This is the deepest 1.4 GHz survey to achieve this large of an area, filling a gap in the phase space between small, deep and large, shallow surveys. It also serves as a pilot project for a larger high-resolution survey with the Expanded Very Large Array. We discuss the technical design of the survey and details of the observations, and we outline our method for data reduction. We present a catalog of 17,969 isolated radio components, for an overall source density of {approx}195 sources deg{sup -2}. The astrometric accuracy of the data is excellent, with an internal check utilizing multiply observed sources yielding an rms scatter of 0.''19 in both right ascension and declination. A comparison to the SDSS DR7 Quasar Catalog further confirms that the astrometry is well tied to the optical reference frame, with mean offsets of 0.''02 {+-} 0.''01 in right ascension, and 0.''01 {+-} 0.''02 in declination. A check of our photometry reveals a small, negative CLEAN-like bias on the level of 35 {mu}Jy. We report on the catalog completeness, finding that 97% of FIRST-detected quasars are recovered in the new Stripe 82 radio catalog, while faint, extended sources are more likely to be resolved out by the resolution bias. We conclude with a discussion of the optical counterparts to the catalog sources, including 76 newly detected radio quasars. The full catalog as well as a search page and cutout server are available online at http://third.ucllnl.org/cgi-bin/stripe82cutout.

  8. Rotary high power transfer apparatus

    NASA Technical Reports Server (NTRS)

    Jacobson, Peter E. (Inventor); Porter, Ryan S. (Inventor)

    1987-01-01

    An apparatus for reducing terminal-to-terminal circuit resistance and enhancing heat transfer in a rotary power transfer apparatus of the roll ring type comprising a connecting thimble for attaching an external power cable to a cone shaped terminal which is attached to a tab integral to an outer ring. An inner ring having a spherical recess mates with the spherical end of a tie connector. A cone shaped terminal is fitted to a second connecting thimble for attaching a second external power cable.

  9. High power microwave switching utilizing a waveguide spark gap.

    PubMed

    Foster, J; Edmiston, G; Thomas, M; Neuber, A

    2008-11-01

    A reduction in the rise time of a 2.85 GHz high power microwave (HPM) pulse is achieved by implementing an overvoltaged spark gap inside a waveguide structure. The spark gap is oriented such that when triggered, the major electric field component of the dominant TE(10) mode is shorted. The transition from a transmissive to a highly reflective microwave structure in a relatively short period of time (tens of nanoseconds) creates a means to switch multimegawatt power levels on a much faster timescale than mechanical switches. An experimental arrangement composed of the waveguide spark gap and a high power circulator is used to reduce the effective rise time of a HPM pulse from a U.S. Air Force AW/PFS-6 radar set from 600 ns down to 50 ns. The resulting HPM pulse exhibits a much more desirable excitation profile when investigating microwave induced dielectric window flashover. Since most theoretical discussions on microwave breakdown assume an ideal step excitation, achieving a "squarelike" pulse is needed if substantial comparison between experiment and theory is sought. An overview of the experimental setup is given along with relevant performance data and comparison with computer modeling of the structure.

  10. 34 GHz Highly Efficient Peniotron with an Axis-Encircling Beam

    NASA Astrophysics Data System (ADS)

    Dressman, L. J.; McDermott, D. B.; Hirata Luhmann, Y., Jr.; Gallagher, D. A.; Spencer, T. A.

    2002-11-01

    The peniotron interaction has proven capable of yielding extremely high efficiency. Electronic conversion efficiency has been demonstrated as high as 75IEEE Trams. On Electron Devices 46, 798 (1999)]. This inherently high efficiency is due to the nature of the interaction which is markedly different from the competing gyrotron interaction. The interaction is optimal for an axis-encircling electron beam and for a perfect beam, the transfer of transverse energy can approach 100objective of the UCD harmonic peniotron is to achieve high overall device efficiency while insuring stability through the use of a fundamental-mode interaction with the second cyclotron harmonic of an axis-encircling beam generated by a Northrop Grumman Cusp gun. Large signal simulation of the device predicts an electronic conversion efficiency of 58with a predicted device efficiency of 47 This work has been supported by AFOSR under Grant F49620-99-1-0297 (MURI MVE). Distribution Statement A: Approved for public release; distribution is unlimited.

  11. Analysis of High Order Modes in 1.3 GHZ CW SRF Electron Linac for a Light Source

    SciTech Connect

    Sukhanov, A.; Vostrikov, A.; Yakovlev, V.

    2013-01-01

    Design of a Light Source (LS) based on the continuous wave superconducting RF (CW SRF) electron linac is currently underway. This facility will provide soft coherent X-ray radiation for a braod spectrum of basic research applications. Quality of the X-ray laser radiation is affected by the electron beam parameters such as the stability of the transverse beam position and longitudinal and transverse beam emittances. High order modes (HOMs) excited in the SRF structures by a passing beam may deteriorate the beam quality and affect the beam stability. Deposition of HOM energy in the walls of SRF cavities adds to the heat load of he cryogenic system and leads to the increased cost of building and operation of the linac. In this paper we evaluate effects of HOMs in an LS CW SRF linac based on Tesla-type 9-cell 1.3 GHz cavities. We analyze non-coherent losses and resonance excitation of HOMs. We estimate heat load due to the very high frequency HOMs. We study influence of the HOMs on the transverse beam dynamics.

  12. Production of highly charged heavy ions by 18 GHz superconducting electron cyclotron resonance at Research Center for Nuclear Physics.

    PubMed

    Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

    2010-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source has been installed as a subject of the azimuthally varying field cyclotron upgrade project (K. Hatanaka et al., in Proceedings of the 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18-22 October 2004, pp. 115-117), in order to increase beam currents and to extend the variety of ions. The production development of several ions has been performed since 2006 and some of them have already been used for user experiments [T. Yorita et al., Rev. Sci. Instrum. 79, 02A311 (2008)]. Further optimizations for each component such as the material of plasma electrode, material, and shape of bias probe and mirror field have been continued and more intense ion beams have been obtained for O, N, and Ar. For the purpose of obtaining highly charged Xe with several microamperes, the optimization of position and shape of plasma electrode and bias disk has also been done and highly charged Xe(32+) beam has been obtained successfully.

  13. High-power dual-fed traveling wave photodetector circuits in silicon photonics.

    PubMed

    Chang, Chia-Ming; Sinsky, Jeffrey H; Dong, Po; de Valicourt, Guilhem; Chen, Young-Kai

    2015-08-24

    We introduce the concept of dual-illuminated photodetectors for high-power applications. Illuminating the photodetector on both sides doubles the number of optical channels, boosting DC and RF power handling capability. This concept is demonstrated utilizing multiple-stage dual-illuminated traveling wave photodetector circuits in silicon photonics, showing a maximum DC photocurrent of 112 mA and a 3-dB bandwidth of 40 GHz at 0.3 mA. Peak continuous-wave RF power is generated up to 12.3 dBm at 2 GHz and 5.3 dBm at 40 GHz, at a DC photocurrent of 55 mA. High speed broadband data signals are detected with eye amplitudes of 2.2 V and 1.3 V at 10 Gb/s and 40 Gb/s, respectively. A theoretical analysis is presented illustrating design tradeoffs for the multiple-stage photodetector circuits based on the bandwidth and power requirements.

  14. A 33 GHz Survey of Local Major Mergers: Estimating the Sizes of the Energetically Dominant Regions from High-resolution Measurements of the Radio Continuum

    NASA Astrophysics Data System (ADS)

    Barcos-Muñoz, L.; Leroy, A. K.; Evans, A. S.; Condon, J.; Privon, G. C.; Thompson, T. A.; Armus, L.; Díaz-Santos, T.; Mazzarella, J. M.; Meier, D. S.; Momjian, E.; Murphy, E. J.; Ott, J.; Sanders, D. B.; Schinnerer, E.; Stierwalt, S.; Surace, J. A.; Walter, F.

    2017-07-01

    We present Very Large Array observations of the 33 GHz radio continuum emission from 22 local ultraluminous and luminous infrared (IR) galaxies (U/LIRGs). These observations have spatial (angular) resolutions of 30-720 pc (0.″07-0.″67) in a part of the spectrum that is likely to be optically thin. This allows us to estimate the size of the energetically dominant regions. We find half-light radii from 30 pc to 1.7 kpc. The 33 GHz flux density correlates well with the IR emission, and we take these sizes as indicative of the size of the region that produces most of the energy. Combining our 33 GHz sizes with unresolved measurements, we estimate the IR luminosity and star formation rate per area and the molecular gas surface and volume densities. These quantities span a wide range (4 dex) and include some of the highest values measured for any galaxy (e.g., {{{Σ }}}{SFR}33 {GHz}≤slant {10}4.1 {M}⊙ {{yr}}-1 {{kpc}}-2). At least 13 sources appear Compton thick ({N}{{H}}33 {GHz}≥slant {10}24 {{cm}}-2). Consistent with previous work, contrasting these data with observations of normal disk galaxies suggests a nonlinear and likely multivalued relation between star formation rate and molecular gas surface density, though this result depends on the adopted CO-to-H2 conversion factor and the assumption that our 33 GHz sizes apply to the gas. Eleven sources appear to exceed the luminosity surface density predicted for starbursts supported by radiation pressure and supernova feedback; however, we note the need for more detailed observations of the inner disk structure. U/LIRGs with higher surface brightness exhibit stronger [C ii] 158 μm deficits, consistent with the suggestion that high energy densities drive this phenomenon.

  15. Investigation of a metallic photonic crystal high power microwave mode converter

    SciTech Connect

    Wang, Dong Qin, Fen; Xu, Sha; Yu, Aimin; Wu, Yong

    2015-02-15

    It is demonstrated that an L band metallic photonic crystal TEM-TE{sub 11} mode converter is suitable for narrow band high power microwave application. The proposed mode converter is realized by partially filling metallic photonic crystals along azimuthal direction in a coaxial transmission line for phase-shifting. A three rows structure is designed and simulated by commercial software CST Microwave Studio. Simulation results show that its conversion efficiency is 99% at the center frequency 1.58 GHz. Over the frequency range of 1.56-1.625 GHz, the conversion efficiency exceeds 90 %, with a corresponding bandwidth of 4.1 %. This mode converter has a gigawatt level power handling capability which is suitable for narrow band high power microwave application. Using magnetically insulated transmission line oscillator(MILO) as a high power microwave source, particle-in-cell simulation is carried out to test the performance of the mode converter. The expected TE{sub 11} mode microwave output is obtained and the MILO works well. Mode conversion performance of the converter is tested by far-field measurement method. And the experimental result confirms the validity of our design. Then, high power microwave experiment is carried out on a Marx-driven Blumlein water line pulsed power accelerator. Microwave frequency, radiated pattern and power are measured in the far-field region and the results agree well with simulation results. The experiment also reveals that no microwave breakdown or pulse shortening took place in the experimental setup.

  16. Investigation of a metallic photonic crystal high power microwave mode converter

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Qin, Fen; Xu, Sha; Yu, Aimin; Wu, Yong

    2015-02-01

    It is demonstrated that an L band metallic photonic crystal TEM-TE11 mode converter is suitable for narrow band high power microwave application. The proposed mode converter is realized by partially filling metallic photonic crystals along azimuthal direction in a coaxial transmission line for phase-shifting. A three rows structure is designed and simulated by commercial software CST Microwave Studio. Simulation results show that its conversion efficiency is 99% at the center frequency 1.58 GHz. Over the frequency range of 1.56-1.625 GHz, the conversion efficiency exceeds 90 %, with a corresponding bandwidth of 4.1 %. This mode converter has a gigawatt level power handling capability which is suitable for narrow band high power microwave application. Using magnetically insulated transmission line oscillator(MILO) as a high power microwave source, particle-in-cell simulation is carried out to test the performance of the mode converter. The expected TE11 mode microwave output is obtained and the MILO works well. Mode conversion performance of the converter is tested by far-field measurement method. And the experimental result confirms the validity of our design. Then, high power microwave experiment is carried out on a Marx-driven Blumlein water line pulsed power accelerator. Microwave frequency, radiated pattern and power are measured in the far-field region and the results agree well with simulation results. The experiment also reveals that no microwave breakdown or pulse shortening took place in the experimental setup.

  17. High power RF solid state power amplifier system

    NASA Technical Reports Server (NTRS)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2011-01-01

    A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

  18. Initial operation of a high-power whispering-gallery-mode gyrotron

    SciTech Connect

    Felch, K.; Ives, L.; Jongewaard, E.; Jory, H.; Spang, S.

    1987-10-01

    Varian has begun the development of a high-power gyrotron based on a whispering-gallery-mode interaction circuit. The first experimental tube has been designed to generate pulsed output powers up to 1 MW at a frequency of 140 GHz. The tube was also designed for CW operation at power levels of several hundred kilowatts. The overall design of the tube is discussed. Fabrication of the tube is nearing completion and initial tests on the tube will be carried out in the near future. 5 refs., 2 figs.

  19. Status of High Power Tests of Normal Conducting Single-Cell Structures

    SciTech Connect

    Dolgashev, V.A.; Tantawi, S.G.; Higashi, Y.; Higo, T.; /KEK, Tsukuba

    2011-11-04

    We report the results of ongoing high power tests of single-cell standing wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the maximum gradient possibilities for normal-conducting rf powered particle beam accelerators. The test setup consists of reusable mode launchers and short test structures powered by SLACs XL-4 klystron. The mode launchers and structures were manufactured at SLAC and KEK and tested at the SLAC klystron test laboratory.

  20. Traveling-Wave Maser for 32 GHz

    NASA Technical Reports Server (NTRS)

    Shell, James; Clauss, Robert

    2009-01-01

    The figure depicts a traveling-wave ruby maser that has been designed (though not yet implemented in hardware) to serve as a low-noise amplifier for reception of weak radio signals in the frequency band of 31.8 to 32.3 GHz. The design offers significant improvements over previous designs of 32-GHz traveling-wave masers. In addition, relative to prior designs of 32-GHz amplifiers based on high-electron-mobility transistors, this design affords higher immunity to radio-frequency interference and lower equivalent input noise temperature. In addition to the basic frequency-band and low-noise requirements, the initial design problem included a requirement for capability of operation in a closed-cycle helium refrigerator at a temperature .4 K and a requirement that the design be mechanically simplified, relative to prior designs, in order to minimize the cost of fabrication and assembly. Previous attempts to build 32- GHz traveling-wave masers involved the use of metallic slow-wave structures comprising coupled transverse electromagnetic (TEM)-mode resonators that were subject to very tight tolerances and, hence, were expensive to fabricate and assemble. Impedance matching for coupling signals into and out of these earlier masers was very difficult. A key feature of the design is a slow-wave structure, the metallic portions of which would be mechanically relatively simple in that, unlike in prior slow-wave structures, there would be no internal metal steps, irises, or posts. The metallic portions of the slow-wave structure would consist only of two rectangular metal waveguide arms. The arms would contain sections filled with the active material (ruby) alternating with evanescent-wave sections. This structure would be transparent in both the signal-frequency band (the aforementioned range of 31.8 to 32.3 GHz) and the pump-frequency band (65.75 to 66.75 GHz), and would impose large slowing factors in both frequency bands. Resonant ferrite isolators would be placed in the

  1. High voltage-high power components for large space power distribution systems

    NASA Technical Reports Server (NTRS)

    Renz, D. D.

    1984-01-01

    Space power components including a family of bipolar power switching transistors, fast switching power diodes, heat pipe cooled high frequency transformers and inductors, high frequency conduction cooled transformers, high power-high frequency capacitors, remote power controllers and rotary power transfer devices were developed. Many of these components such as the power switching transistors, power diodes and the high frequency capacitor are commercially available. All the other components were developed to the prototype level. The dc/dc series resonant converters were built to the 25 kW level.

  2. 80-GHz MMIC HEMT Voltage-Controlled Oscillator

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene; Radisic, Vesna; Micovic, Miro; Hu, Ming; Janke, Paul; Ngo, Catherine; Nguyen, Loi

    2003-01-01

    A voltage-controlled oscillator (VCO) that operates in the frequency range from 77.5 to 83.5 GHz has been constructed in the form of a monolithic microwave integrated circuit (MMIC) that includes high-electron-mobility transistors (HEMTs). This circuit is a prototype of electronically tunable signal sources in the 75-to-110-GHz range, needed for communication, imaging, and automotive radar applications, among others. This oscillator (see Figure 1) includes two AlInAs/GaInAs/InP HEMTs. One HEMT serves mainly as an oscillator gain element. The other HEMT serves mainly as a varactor for controlling the frequency: the frequency-control element is its gate-to-source capacitance, which is varied by changing its gate supply voltage. The gain HEMT is biased for class-A operation (meaning that current is conducted throughout the oscillation cycle). Grounded coplanar waveguides are used as impedance-matching transmission lines, the input and output matching being chosen to sustain oscillation and maximize output power. Air bridges are placed at discontinuities to suppress undesired slot electromagnetic modes. A high density of vias is necessary for suppressing a parallel-plate electromagnetic mode that is undesired because it can propagate energy into the MMIC substrate. Previous attempts at constructing HEMT-based oscillators yielded circuits with relatively low levels of output power and narrow tuning ranges. For example, one HEMT VCO reported in the literature had an output power of 7 dBm (.5 mW) and a tuning range 2-GHz wide centered approximately at a nominal frequency of 77 GHz. In contrast, as shown in Figure 2, the present MMIC HEMT VCO puts out a power of 12.5 dBm (.18 mW) or more over the 6-GHz-wide frequency range from 77.5 to 83.5 GHz

  3. Numerical modelling of thermal effects in rats due to high-field magnetic resonance imaging (0.5 1 GHz)

    NASA Astrophysics Data System (ADS)

    Trakic, Adnan; Crozier, Stuart; Liu, Feng

    2004-12-01

    A finite-difference time-domain (FDTD) thermal model has been developed to compute the temperature elevation in the Sprague Dawley rat due to electromagnetic energy deposition in high-field magnetic resonance imaging (MRI). The field strengths examined ranged from 11.75-23.5 T (corresponding to 1H resonances of 0.5-1 GHz) and an N-stub birdcage resonator was used to both transmit radio-frequency energy and receive the MRI signals. With an in-plane resolution of 1.95 mm, the inhomogeneous rat phantom forms a segmented model of 12 different tissue types, each having its electrical and thermal parameters assigned. The steady-state temperature distribution was calculated using a Pennes 'bioheat' approach. The numerical algorithm used to calculate the induced temperature distribution has been successfully validated against analytical solutions in the form of simplified spherical models with electrical and thermal properties of rat muscle. As well as assisting with the design of MRI experiments and apparatus, the numerical procedures developed in this study could help in future research and design of tumour-treating hyperthermia applicators to be used on rats in vivo.

  4. Numerical modelling of thermal effects in rats due to high-field magnetic resonance imaging (0.5-1 GHZ).

    PubMed

    Trakic, Adnan; Crozier, Stuart; Liu, Feng

    2004-12-21

    A finite-difference time-domain (FDTD) thermal model has been developed to compute the temperature elevation in the Sprague Dawley rat due to electromagnetic energy deposition in high-field magnetic resonance imaging (MRI). The field strengths examined ranged from 11.75-23.5 T (corresponding to 1H resonances of 0.5-1 GHz) and an N-stub birdcage resonator was used to both transmit radio-frequency energy and receive the MRI signals. With an in-plane resolution of 1.95 mm, the inhomogeneous rat phantom forms a segmented model of 12 different tissue types, each having its electrical and thermal parameters assigned. The steady-state temperature distribution was calculated using a Pennes 'bioheat' approach. The numerical algorithm used to calculate the induced temperature distribution has been successfully validated against analytical solutions in the form of simplified spherical models with electrical and thermal properties of rat muscle. As well as assisting with the design of MRI experiments and apparatus, the numerical procedures developed in this study could help in future research and design of tumour-treating hyperthermia applicators to be used on rats in vivo.

  5. High-frequency (95 GHz) electron paramagnetic resonance study of the photoinduced charge transfer in conjugated polymer-fullerene composites

    NASA Astrophysics Data System (ADS)

    Ceuster, J. De; Goovaerts, E.; Bouwen, A.; Hummelen, J. C.; Dyakonov, V.

    2001-11-01

    Light-induced electron paramagnetic resonance (LEPR) measurements are reported in composites of poly(2-methoxy-5-(3-,7-dimethyloctyloxy)-1,4-phenylenevinylene) (MDMO-PPV) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), a soluble derivative of C60. Under illumination of the sample, two paramagnetic species are formed due to photoinduced charge transfer between conjugated polymer and fullerene. One is the positive polaron P+ on the polymer backbone and the other is the radical anion on the methanofullerene. Using high-frequency (95 GHz) LEPR it was possible to separate these two contributions to the spectrum on the basis of their g factors, and moreover to resolve the g anisotropy for both radicals. The positive polaron on the conjugated polymer chain possesses axial symmetry with g values g||=2.0034(1) and g⊥=2.0024(1). EPR on low doped polymer gave extra proof for the assignment to the positive polaron. The negatively charged methanofullerene has a lower, rhombic symmetry with gx=2.0003(1), gy=2.0001(1), and gz=1.9982(1). Different spin-lattice relaxation of both species gives rise to a rapid passage effect for the positive polaron spectrum.

  6. Analysis of a high power microwave radial line slot antenna.

    PubMed

    Peng, Shengren; Yuan, Chengwei; Shu, Ting

    2013-07-01

    A traditional radial line slot antenna (RLSA) is a high gain planar array. To improve the power handling capacity, we design a radial line slow wave structure which replaces a traditional dielectric sheet in the radial waveguide of the traditional RLSA. This high power microwave (HPM) RLSA is fed from a double-layered radial line waveguide to realize the directional radiation of the microwave. However, the track of the widen slot array on the upper waveguide could cause large reflection, which disturbs the normal antenna operation, accordingly a reflection canceling slot is added to the lower waveguide, the key technology employed in the design of the HPM RLSA and the antenna return-loss is effectively improved. This article mainly gives the design theory of this antenna, which is confirmed by the simulations and experiments. At 9.4 GHz, the calculated aperture efficiency reaches more than 40%, the reflectance is less than 0.1, the radiation efficiency is more than 99% and its measured power-handling capacity exceeds 700 MW.

  7. InP and InGaAs Submicron Gate Microwave Power Transistors for 20 GHz Applications

    DTIC Science & Technology

    1991-06-01

    R . Nguyen, R . A . Stall, and M. A . McKee, "Indium Gallium Arsenide Microwave Power Transistors", IEEE Trans. Microwave Theory Tech., to appear in 1991...4 AD-A238 595 REPORT DOCUMENTATIOII 111IIIIIIII’___ 11 11 IN’ 11111 111 U 1 111 nI, i-- jt ncode’ a -U monP) nnq1n ! mrr~jo Ccad a ’ tn4 op, 1f Mad...Maximum 200 WOUEsl .InGaAs MISFETs witl, 0.7 gm gate lengths and 0.2 mm gate widths have demnonstratedl a1 I)1lut~IlTI i1-t 0.92 X/mm at 18 G1I1z with a

  8. A new high-performance sideband-separating mixer for 650GHz

    NASA Astrophysics Data System (ADS)

    Hesper, R.; Khudchenko, A.; Baryshev, A. M.; Barkhof, J.; Mena, F. P.

    2016-07-01

    In the modular sideband-separating mixers that we built over the last years, we observe a clear anti-correlation between the image rejection ratio obtained with a certain block and its noise performance, as well as strong correlations between the image rejection and imbalances in the pumping of the mixer devices. We report on the mechanisms responsible for these effects, and conclude that the reduction of the image rejection is largely explained by the presence of standing waves. We demonstrate the rejection ratio to be very sensitive to those. In principle, all potential round-trip paths should be terminated in matched loads, so no standing waves can develop. In practice, the typical high reflections from the SIS mixers combined with imperfect loads and non-negligible input/output reflections of the other components give many opportunities for standing waves. Since most of the loss of image rejection can be attributed to standing waves, the anti-correlation with the noise temperature can be understood by considering any excess loss in the structure, as the waveguides start acting as distribured loads. This reduces the standing waves, and thereby improves the rejection ratio, at the expense of noise temperature. Based on these experiences, we designed a new waveguide structure, with a basic waveguide size of 400×200 μm and improved loads. Strong emphasis was placed on low input and output reflections of the waveguide components, in some places at the cost of phase or amplitude imbalance. For the latter there is ample margin not to impair the performance, however. Apart from further details of the design, we present the first results of the new mixers, tested in a modified production-level ALMA Band 9 receiver, and show that even in an unfinished state, it simultaneously meets requirements for image rejection and noise temperature.

  9. HIGH POWER FERRITE PHASE SHIFTER

    DTIC Science & Technology

    power tests to 100 kw peak are reported for waveguide configurations containing (1) single crystal lithium ferrite; (2) polycrystalline cubic ... structure , nickel ferrite; and (3) polycrystalline hexagonal structure nickel-cobalt ’W’ ferrite with its magnetic anisotropy oriented parallel to the applied

  10. High average power induction accelerators

    SciTech Connect

    Swingle, J.C.

    1985-10-01

    The induction accelerator is discussed with respect to general background and concept, beam transport, scaling, pulse power technology, and the electron beam injector. A discussion of the factors which affect the scaling of the intensity of the beam is given. Limiting factors include collective forces in the beam, virtual cathode formation, surroundings, and beam breakup instability. 24 refs., 11 figs. (WRF)

  11. An explosively driven high-power microwave pulsed power system

    NASA Astrophysics Data System (ADS)

    Elsayed, M. A.; Neuber, A. A.; Dickens, J. C.; Walter, J. W.; Kristiansen, M.; Altgilbers, L. L.

    2012-02-01

    The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

  12. Low-voltage, high-power T/R-switch MMIC using LC resonators

    NASA Astrophysics Data System (ADS)

    Tokumitsu, Tsuneo; Toyoda, Ichihiko; Aikawa, Masayoshi

    1995-05-01

    A novel T/R switch is proposed for high-power/low-distortion operation at a low control voltage. LC-resonant switches composed of inductors, capacitors, and switch FET's are incorporated in TX and RX arms to provide a reverse control scheme that removes the rf-voltage limitation in the transmit mode. A 1.9-GHz LC-resonant T/R switch MMIC with a total FET periphery of 3.36 mm exhibits 3rd IMR less than - 40 dB for an input power up to 31 dBm when controlled at 0 V/ - 2 V. This MMIC occupies an area as small as less than 2 x 2 mm. This will make it possible to implement advanced T/R-switches at PCS and ISM frequencies below 5 GHz.

  13. Latest Progress in High Power VECSELs

    DTIC Science & Technology

    2013-01-01

    AFRL-RY-WP-TP-2013-0030 LATEST PROGRESS IN HIGH POWER VECSELs (POSTPRINT) Robert Bedford Optoelectronic Technology Branch Aerospace...SUBTITLE LATEST PROGRESS IN HIGH POWER VECSELs (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62204F... VECSELs ) have captured the interest of high-brightness semiconductor researchers, primarily due to their simplicity in design, power scalability, and

  14. Operation of high power converters in parallel

    NASA Technical Reports Server (NTRS)

    Decker, D. K.; Inouye, L. Y.

    1993-01-01

    High power converters that are used in space power subsystems are limited in power handling capability due to component and thermal limitations. For applications, such as Space Station Freedom, where multi-kilowatts of power must be delivered to user loads, parallel operation of converters becomes an attractive option when considering overall power subsystem topologies. TRW developed three different unequal power sharing approaches for parallel operation of converters. These approaches, known as droop, master-slave, and proportional adjustment, are discussed and test results are presented.

  15. First Results of the Superconducting ECR Ion Source Venus with 28 GHz

    SciTech Connect

    Leitner, D.; Lyneis, C.M.; Abbott, S.R.; Dwinell, R.D.; Collins, D.; Leitner, M.

    2005-03-15

    VENUS (Versatile ECR ion source for NUclear Science) is a next generation superconducting ECR ion source, designed to produce high current, high charge state ions for the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. VENUS also serves as the prototype ion source for the RIA (Rare Isotope Accelerator) front end. The magnetic confinement configuration consists of three superconducting axial coils and six superconducting radial coils in a sextupole configuration. The nominal design fields of the axial magnets are 4T at injection and 3T at extraction; the nominal radial design field strength at the plasma chamber wall is 2T, making VENUS the world most powerful ECR plasma confinement structure. From the beginning, VENUS has been designed for optimum operation at 28 GHz with high power (10 kW).In 2003 the VENUS ECR ion source was commissioned at 18 GHz, while preparations for 28 GHz operation were being conducted. During this commissioning phase with 18 GHz, tests with various gases and metals have been performed with up to 2000 W RF power. At the initial commissioning tests at 18 GHz, 1100 e{mu}A of O6+, 160 e{mu}A of Xe20+, 160 e{mu}A of Bi25+ and 100 e{mu}A of Bi30+ and 11 e{mu}A of Bi41+ were produced.In May 2004 the 28 GHz microwave power has been coupled into the VENUS ECR ion source. At initial operation more than 320 e{mu}A of Xe20+ (twice the amount extracted at 18 GHz), 240 e{mu}A of Bi24+ and Bi25+, and 245 e{mu}A of Bi29+ were extracted. The paper briefly describes the design of the VENUS source, the 28 GHz microwave system and its beam analyzing system. First results at 28 GHz including emittance measurements are presented.

  16. High Power Electromagnetic (HPEM) Threat Analysis

    DTIC Science & Technology

    2008-04-01

    EMERGING THREATS ...... 13 HEMP coupling characteristics ............................................................................... 13 High power...microwave (HPEM) coupling characteristics ..................................... 16 High power microwave: local protective measures...ncy (W1 Figure 22. Various bands summarizing EM threats. HEMP coupling characteristics In the early 1960’s, researchers proposed a theory that a high

  17. A high power active circulator using GaN MMIC power amplifiers

    NASA Astrophysics Data System (ADS)

    Liming, Gu; Wenquan, Che; Huang, Fan-Hsiu; Chiu, Hsien-Chin

    2014-11-01

    This paper presents a 2.4 GHz hybrid integrated active circulator consisting of three power amplifiers and three PCB-based Wilkinson power dividers. The power amplifiers were designed and fabricated in a standard 0.35-μm AlGaN/GaN HEMT technology, and combined with three traditional power dividers on FR4 using bonding wires. Due to the isolation of power dividers, the isolation between three ports is achieved; meanwhile, due to the unidirectional characteristics of the power amplifiers, the nonreciprocal transfer characteristic of the circulator is realized. The measured insertion gain of the proposed active circulator is about 2-2.7 dB at the center frequency of 2.4 GHz, the isolation between three ports is better than 20 dB over 1.2-3.4 GHz, and the output power of the designed active circulator achieves up to 20.1-21.2 dBm at the center frequency.

  18. Behavioral Performance in Monkeys Exposed to Tempo High-Peak-Power Microwave Pulses at 3 GHz.

    DTIC Science & Technology

    1993-12-01

    exposure across all sessions as well as another badge and TLD to measure x-ray exposure during a single session . The cumulative exposure TLD dosimetry...ranges were .543 rem to 1.645 rem (Mean .965, ± .101 SEM). Single session ranges were 0.009 to 0.046 rcm (Mean .016, ± .005 SEM). Statistical Analyses. The

  19. 230 GHz VLBI Observations of M87: Event-horizon-scale Structure during an Enhanced Very-high-energy γ-Ray State in 2012

    NASA Astrophysics Data System (ADS)

    Akiyama, Kazunori; Lu, Ru-Sen; Fish, Vincent L.; Doeleman, Sheperd S.; Broderick, Avery E.; Dexter, Jason; Hada, Kazuhiro; Kino, Motoki; Nagai, Hiroshi; Honma, Mareki; Johnson, Michael D.; Algaba, Juan C.; Asada, Keiichi; Brinkerink, Christiaan; Blundell, Ray; Bower, Geoffrey C.; Cappallo, Roger; Crew, Geoffrey B.; Dexter, Matt; Dzib, Sergio A.; Freund, Robert; Friberg, Per; Gurwell, Mark; Ho, Paul T. P.; Inoue, Makoto; Krichbaum, Thomas P.; Loinard, Laurent; MacMahon, David; Marrone, Daniel P.; Moran, James M.; Nakamura, Masanori; Nagar, Neil M.; Ortiz-Leon, Gisela; Plambeck, Richard; Pradel, Nicolas; Primiani, Rurik A.; Rogers, Alan E. E.; Roy, Alan L.; SooHoo, Jason; Tavares, Jonathan-León; Tilanus, Remo P. J.; Titus, Michael; Wagner, Jan; Weintroub, Jonathan; Yamaguchi, Paul; Young, Ken H.; Zensus, Anton; Ziurys, Lucy M.

    2015-07-01

    We report on 230 GHz (1.3 mm) very long baseline interferometry (VLBI) observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona, and Cedar Flat in California. For the first time, we have acquired 230 GHz VLBI interferometric phase information on M87 through measurement of the closure phase on the triangle of long baselines. Most of the measured closure phases are consistent with 0° as expected by physically motivated models for 230 GHz structure such as jet models and accretion disk models. The brightness temperature of the event-horizon-scale structure is ˜ 1× {10}10 K derived from the compact flux density of ˜1 Jy and the angular size of ˜40 μ {as} ˜ 5.5 {R}{{s}}, which is broadly consistent with the peak brightness of the radio cores at 1-86 GHz located within ˜ {10}2 {R}{{s}}. Our observations occurred in the middle of an enhancement in very-high-energy (VHE) γ -ray flux, presumably originating in the vicinity of the central black hole. Our measurements, combined with results of multi-wavelength observations, favor a scenario in which the VHE region has an extended size of ˜20-60 {R}{{s}}.

  20. 16 channel GHz low noise SWIR photoreceivers

    NASA Astrophysics Data System (ADS)

    Bai, Xiaogang; Yuan, Ping; McDonald, Paul; Boisvert, Joseph; Chang, James; Woo, Robyn; Labios, Eduaro; Sudharsanan, Rengarajan; Krainak, Michael; Yang, Guangning; Sun, Xiaoli; Lu, Wei; McIntosh, Dion; Zhou, Qiugui; Campbell, Joe

    2012-06-01

    Future NASA light detection and ranging (LIDAR) mapping systems require multi-channel receivers with high sensitivity and bandwidth operating at 1-1.5 μm wavelengths. One of the ways to improve the system performance is to improve the sensitivity of photoreceiver. InGaAs avalanche photodiode (APD) sensor technology is considered for this wavelength region because of high reliability. However, commercially available InGaAs APDs have low sensitivity due to the high excess-noise of InP material. Spectrolab has been developing low excess noise InGaAs avalanche photodiodes (APDs) with impact ionization engineering (I2E) structures and recently, APDs with excess noise factor of 0.15 have been demonstrated using an I2E design. Single channel photoreceivers built using low noise I2E APDs show a noise equivalent power (NEP) of 150 fW/rt(Hz) over a bandwidth of 1 GHz, a record for InGaAs based APDs. A 16 channel GHz SWIR photoreceiver was designed and built at Spectrolab. The photoreceiver was designed to work with a custom fiber bundle which couples the light from telescope to detectors. The photoreceiver shows a system level NEP less than 300 fW/rt(Hz) with 1 GHz bandwidth.

  1. High-power, high-frequency, annular-beam free-electron maser

    SciTech Connect

    Fazio, M.V.; Carlsten, B.E.; Earley, L.M.; Fortgang, C.M.; Haynes, W.B.; Haddock, P.C.

    1998-11-01

    The authors have developed a 15--17 GHz free electron maser (FEM) capable of producing high power pulses with a phase stability appropriate for linear collider applications. The electron beam source is a 1 {micro}s, 800 kV, 5 kA, 6-cm-dia annular electron beam machine called BANSHEE. The beam interacts with the TM{sub 02} mode Raman FEM amplifier in a corrugated cylindrical waveguide where the beam runs close to the interaction device walls to reduce the power density in the fields. They studied the phase stability by analyzing the dispersion relation for an axial FEL, in which the rf field was transversely wiggled and the electron trajectories were purely longitudinal. Detailed particle-in-cell simulations demonstrated the transverse wiggling of the rf mode and the axial FEL interaction and explicit calculations of the growing root of the dispersion relation are included to verify the phase stability.

  2. A High Power Frequency Doubled Fiber Laser

    NASA Technical Reports Server (NTRS)

    Thompson, Robert J.; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute

    2003-01-01

    This viewgraph presentation reports on the development of a high power 780 nm laser suitable for space applications of laser cooling. A possible solution is to use frequency doubling of high power 1560 nm telecom lasers. The presentation shows a diagram of the frequency conversion, and a graph of the second harmonic generation in one crystal, and the use of the cascading crystals. Graphs show the second harmonic power as a function of distance between crystals, second harmonic power vs. pump power, tunability of laser systems.

  3. A High Power Frequency Doubled Fiber Laser

    NASA Technical Reports Server (NTRS)

    Thompson, Robert J.; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute

    2003-01-01

    This viewgraph presentation reports on the development of a high power 780 nm laser suitable for space applications of laser cooling. A possible solution is to use frequency doubling of high power 1560 nm telecom lasers. The presentation shows a diagram of the frequency conversion, and a graph of the second harmonic generation in one crystal, and the use of the cascading crystals. Graphs show the second harmonic power as a function of distance between crystals, second harmonic power vs. pump power, tunability of laser systems.

  4. Environmental assessment for the Satellite Power System (SPS): studies of honey bees exposed to 2. 45 GHz continuous-wave electromagnetic energy

    SciTech Connect

    Gary, N E; Westerdahl, B B

    1980-12-01

    A system for small animal exposure was developed for treating honey bees, Apis mellifera L., in brood and adult stages, with 2.45 GHz continuous wave microwaves at selected power densities and exposure times. Post-treatment brood development was normal and teratological effects were not detected at exposures of 3 to 50 mw/cm/sup 2/ for 30 minutes. Post-treatment survival, longevity, orientation, navigation, and memory of adult bees were also normal after exposures of 3 to 50 mw/cm/sup 2/ for 30 minutes. Post-treatment longevity of confined bees in the laboratory was normal after exposures of 3 to 50 mw/cm/sup 2/ for 24 hours. Thermoregulation of brood nest, foraging activity, brood rearing, and social interaction were not affected by chronic exposure to 1 mw/cm/sup 2/ during 28 days. In dynamic behavioral bioassays the frequency of entry and duration of activity of unrestrained, foraging adult bees was identical in microwave-exposed (5 to 40 mw/cm/sup 2/) areas versus control areas.

  5. New JVLA observations at 3 GHz and 5.5 GHz of the "Kite" radio source in Abell 2626

    NASA Astrophysics Data System (ADS)

    Ignesti, A.; Gitti, M.; Brunetti, G.; Feretti, L.; Giovannini, G.

    2017-07-01

    Context. We report on new Karl Jansky Very Large Array (JVLA) observations performed at 3 GHz and 5.5 GHz of Abell 2626. The cluster has been the object of several studies in recent years due to its peculiar radio emission, which shows a complex system of symmetric radio arcs characterized by a steep spectrum. The origin of these radio sources is still unclear. Due to their mirror symmetry toward the center, it has been proposed that they may be created by pairs of precessing jets powered by the inner active galactic nuclei (AGN). Aims: The new JVLA observations were requested with the specific aim of detecting extended emission on frequencies higher than 1.4 GHz, in order to constrain the jet-precession model by analyzing the spectral index and radiative age patterns along the arcs. Methods: We performed a standard data reduction of the JVLA datasets with the software CASA. By combining the new 3 GHz data with the archival 1.4 GHz VLA dataset we produced a spectral index map of the extended emission, and then estimated the radiative age of the arcs by assuming that the plasma was accelerated in moving hot-spots tracing the arcs. Results: Thanks to the high sensitivity of the JVLA, we achieve the detection of the arcs at 3 GHz and extended emission at 5.5 GHz. We measure a mean spectral index <- 2.5 for the arcs up to 3 GHz. No clear trend in spectral index or radiative age is detected across the arcs, which may challenge the interpretation based on precession or put strong constraints on the jet-precession period. In particular, by analyzing the radiative age distribution along the arcs, we were able to provide for the first time a timescale <26 Myr of the jet-precession period.

  6. High Density Power Converters for Photovoltaic Power Management

    NASA Astrophysics Data System (ADS)

    Sangwan, Rahul

    In typical photovoltaic systems, PV cells are connected in series to achieve high output voltages, which decreases conduction losses and helps the downstream power electronics operate at higher efficiencies. A series connection means that the current through the string is limited by the worst case cell, substring, or module, which can result in suboptimal operation of the rest of the string. Given how even small shading can have a large effect on performance, there has been growing interest in the use of distributed power management architectures to mitigate losses from variation in PV systems. In particular, partial power processing converters have gained traction as a means to improve the performance of PV arrays with small, distributed converters that configure in parallel with PV cells. These converters can use low voltage components, only process a fraction of the total power allowing them to achieve higher efficiencies and power density and also have higher reliability. This work details the design and operation of a partial power processing converter implemented as a Resonant Switched Capacitor (ReSC) converter. An integrated circuit (IC) is designed in 0.18 mum CMOS process. Operation at high frequencies (20-50 MHz) allows high levels of integration with air core inductors directly attached to the die through a gold bump, solder reflow process. Test results for the IC are presented with power density and efficiency metrics. The IC is then used as a partial power processing converter to implement equalization with a specially constructed PV panel. The converter is shown to mitigate power loss due to mismatch.

  7. A high-average power tapered FEL amplifier at submillimeter frequencies using sheet electron beams and short-period wigglers

    SciTech Connect

    Bidwell, S.W.; Radack, D.J.; Antonsen, T.M. Jr.; Booske, J.H.; Carmel, Y.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Latham, P.E.; Zhang, Z.X.

    1990-01-01

    A high-average-power FEL amplifier operating at submillimeter frequencies is under development at the University of Maryland. Program goals are to produce a CW, {approximately}1 MW, FEL amplifier source at frequencies between 280 GHz and 560 GHz. To this end, a high-gain, high-efficiency, tapered FEL amplifier using a sheet electron beam and a short-period (superconducting) wiggler has been chosen. Development of this amplifier is progressing in three stages: (1) beam propagation through a long length ({approximately}1 m) of short period ({lambda}{sub {omega}} = 1 cm) wiggler, (2) demonstration of a proof-of-principle amplifier experiment at 98 GHz, and (3) designs of a superconducting tapered FEL amplifier meeting the ultimate design goal specifications. 17 refs., 1 fig., 1 tab.

  8. Spatial and Spectral Brightness Enhancement of High Power Semiconductor Lasers

    NASA Astrophysics Data System (ADS)

    Leidner, Jordan Palmer

    The performance of high-power broad-area diode lasers is inhibited by beam filamentation induced by free-carrier-based self-focusing. The resulting beam degradation limits their usage in high-brightness, high-power applications such as pumping fiber lasers, and laser cutting, welding, or marking. Finite-difference propagation method simulations via RSoft's BeamPROP commercial simulation suite and a custom-built MATLAB code were used for the study and design of laser cavities that suppress or avoid filamentation. BeamPROP was used to design a tapered, passive, multi-mode interference cavity for the creation of a self-phase-locking laser array, which is comprised of many single-mode gain elements coupled to a wide output coupler to avoid damage from local high optical intensities. MATLAB simulations were used to study the effects of longitudinal and lateral cavity confinement on lateral beam quality in conventional broad-area lasers. This simulation was expanded to design a laser with lateral gain and index prescription that is predicted to operate at or above state-of-the-art powers while being efficiently coupled to conventional telecom single-mode optical fibers. Experimentally, a commercial broad-area laser was coupled in the far-field to a single-mode fiber Bragg grating to provide grating-stabilized single-mode laser feedback resulting in measured spectral narrowing for efficient pump absorption. Additionally a 19 GHz-span, spatially resolved, self-heterodyne measurement was made of a broad-area laser to study the evolution/devolution of the mode content of the emitted laser beam with increasing power levels.

  9. Microwave interferometer using 94-GHz solid-state sources

    SciTech Connect

    Coffield, F.E.; Thomas, S.R.; Lang, D.D.; Stever, R.D.

    1983-11-14

    A 94-GHz microwave interferometer has been designed for the Tandem Mirror Experiment Upgrade and the Mirror Fusion Test Facility to replace the 140-GHz system. The new system is smaller and has modular single-channel units designed for high reliability. It is magnetically shielded and can be mounted close to the machine, which allows the use of lower power solid-state sources. Test results of the 94-GHz prototype indicate that the phase resolution is better than 1/sup 0/, the Impatt FM noise is 5 MHz wide, and the Gunn FM noise is 6 kHz wide. This paper presents the antenna designs along with the test results and discusses the unique problems associated with diagnosing a high electron temperature plasma in the presence of electron cyclotron resonant heating.

  10. High Power/High Temperature Battery Development

    DTIC Science & Technology

    1992-09-01

    dcruit stand The bipolar conliguration permits cello be closely packed, share cell walls, and combine the functions of wall and intercell connector. The...LUthco Symp. on Lithium Chem., Ed. R. Bach , John Wiley and Sons, N.Y. M. Wliams, st. al., Proc. 32nd Power Sources Conf., p 658 If (1986). C.D...on Electron Devices ATTN: Documents 2011 Crystal Drive, Suite 307 002 Adington, VA 22202 Page 43 Plop 2 O nlPage Elstronlo Technooyand DvcsLaomtory

  11. Low Power Compact Radio Galaxies at High Angular Resolution

    SciTech Connect

    Giroletti, Marcello; Giovannini, G.; Taylor, G.B.; /KIPAC, Menlo Park /NRAO, Socorro

    2005-06-30

    We present sub-arcsecond resolution multi-frequency (8 and 22 GHz) VLA images of five low power compact (LPC) radio sources, and phase referenced VLBA images at 1.6 GHz of their nuclear regions. At the VLA resolution we resolve the structure and identify component positions and flux densities. The phase referenced VLBA data at 1.6 GHz reveals flat-spectrum, compact cores (down to a few milliJansky) in four of the five sources. The absolute astrometry provided by the phase referencing allows us to identify the center of activity on the VLA images. Moreover, these data reveal rich structures, including two-sided jets and secondary components. On the basis of the arcsecond scale structures and of the nuclear properties, we rule out the presence of strong relativistic effects in our LPCs, which must be intrinsically small (deprojected linear sizes {approx}< 10 kpc). Fits of continuous injection models reveal break frequencies in the GHz domain, and ages in the range 10{sup 5}-10{sup 7} yrs. In LPCs, the outermost edge may be advancing more slowly than in more powerful sources or could even be stationary; some LPCs might also have ceased their activity. In general, the properties of LPCs can be related to a number of reasons, including, but not limited to: youth, frustration, low kinematic power jets, and short-lived activity in the radio.

  12. High Power Josephson Effect Sources

    DTIC Science & Technology

    1994-09-01

    large spacing was nsed ,along with cooling water, os Iao a d$ to ensure the substrate temperature did not rise durn theCox flow Osiltr.adsaljnto ry~ h m...Here two arra’s. a 400 s.m Josephson effect detector and an SIS mixer are "I integrated on a single silicon substrate . One array func- tions as the...junction’s shunt resistor, on array’s output power and detector’s current- voltage characteristics are also discussed. I. INTRODUCTION - U Phb &z locked

  13. Test facilities for high power electric propulsion

    NASA Technical Reports Server (NTRS)

    Sovey, James S.; Vetrone, Robert H.; Grisnik, Stanley P.; Myers, Roger M.; Parkes, James E.

    1991-01-01

    Electric propulsion has applications for orbit raising, maneuvering of large space systems, and interplanetary missions. These missions involve propulsion power levels from tenths to tens of megawatts, depending upon the application. General facility requirements for testing high power electric propulsion at the component and thrust systems level are defined. The characteristics and pumping capabilities of many large vacuum chambers in the United States are reviewed and compared with the requirements for high power electric propulsion testing.

  14. Photoconductive switching for high power microwave generation

    SciTech Connect

    Pocha, M.D.; Hofer, W.W.

    1990-10-01

    Photoconductive switching is a technology that is being increasingly applied to generation of high power microwaves. Two primary semiconductors used for these devices are silicon and gallium arsenide. Diamond is a promising future candidate material. This paper discusses the important material parameters and switching modes, critical issues for microwave generation, and future directions for this high power, photoconductive switching technology.

  15. Very High Power THz Radiation Sources.

    PubMed

    Carr, G L; Martin, M C; McKinney, W R; Jordan, K; Neil, G R; Williams, G P

    2003-06-01

    We report the production of high power (20watts average, ∼ 1 Megawatt peak) broadbandTHz light based on coherent emission fromrelativistic electrons. Such sources areideal for imaging, for high power damagestudies and for studies of non-linearphenomena in this spectral range. Wedescribe the source, presenting theoreticalcalculations and their experimentalverification. For clarity we compare thissource with one based on ultrafast lasertechniques.

  16. High power laser perforating tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-04-22

    ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

  17. Automated System Tests High-Power MOSFET's

    NASA Technical Reports Server (NTRS)

    Huston, Steven W.; Wendt, Isabel O.

    1994-01-01

    Computer-controlled system tests metal-oxide/semiconductor field-effect transistors (MOSFET's) at high voltages and currents. Measures seven parameters characterizing performance of MOSFET, with view toward obtaining early indication MOSFET defective. Use of test system prior to installation of power MOSFET in high-power circuit saves time and money.

  18. An Aeronautical-Mobile 20/30 GHz Satellite-Tracking Antenna for High Data Rate Satcom

    NASA Technical Reports Server (NTRS)

    Densmore, A.; Guler, M.

    1995-01-01

    An antenna for use on an aircraft has been developed and tested for transmissions to and from a communications satellite. The antenna operates at 20/30 GHz and a data rate of 512 kbps, and it does not require modifying the shape of the aircraft fuselage.

  19. An Aeronautical-Mobile 20/30 GHz Satellite-Tracking Antenna for High Data Rate Satcom

    NASA Technical Reports Server (NTRS)

    Densmore, A.; Guler, M.

    1995-01-01

    An antenna for use on an aircraft has been developed and tested for transmissions to and from a communications satellite. The antenna operates at 20/30 GHz and a data rate of 512 kbps, and it does not require modifying the shape of the aircraft fuselage.

  20. A high efficiency C-band internally-matched harmonic tuning GaN power amplifier

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Zhao, B. C.; Zheng, J. X.; Zhang, H. S.; Zheng, X. F.; Ma, X. H.; Hao, Y.; Ma, P. J.

    2016-09-01

    In this paper, a high efficiency C-band gallium nitride (GaN) internally-matched power amplifier (PA) is presented. This amplifier consists of 2-chips of self-developed GaN high-electron mobility transistors (HEMTs) with 16 mm total gate width on SiC substrate. New harmonic manipulation circuits are induced both in the input and output matching networks for high efficiency matching at fundamental and 2nd-harmonic frequency, respectively. The developed amplifier has achieved 72.1% power added efficiency (PAE) with 107.4 W output power at 5 GHz. To the best of our knowledge, this amplifier exhibits the highest PAE in C-band GaN HEMT amplifiers with over 100 W output power. Additionally, 1000 hours' aging test reveals high reliability for practical applications.

  1. High efficiency solar photovoltaic power module concept

    NASA Technical Reports Server (NTRS)

    Bekey, I.

    1978-01-01

    The investigation of a preliminary concept for high efficiency solar power generation in space is presented. The concept was a synergistic combination of spectral splitting, tailored bandgap cells, high concentration ratios, and cool cell areas.

  2. The NASA CSTI High Capacity Power Project

    NASA Astrophysics Data System (ADS)

    Winter, J.; Dudenhoefer, J.; Juhasz, A.; Schwarze, G.; Patterson, R.; Ferguson, D.; Schmitz, P.; Vandersande, J.

    The elements of the Civilian Space Technology Initiative (CSTI) High Capacity Power Project include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. The overall project will develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements are presented, along with revised goals and project timelines recently developed.

  3. Effect of source tuning parameters on the plasma potential of heavy ions in the 18 GHz high temperature superconducting electron cyclotron resonance ion source.

    PubMed

    Rodrigues, G; Baskaran, R; Kukrety, S; Mathur, Y; Kumar, Sarvesh; Mandal, A; Kanjilal, D; Roy, A

    2012-03-01

    Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz high temperature superconducting ECR ion source, PKDELIS [C. Bieth, S. Kantas, P. Sortais, D. Kanjilal, G. Rodrigues, S. Milward, S. Harrison, and R. McMahon, Nucl. Instrum. Methods B 235, 498 (2005); D. Kanjilal, G. Rodrigues, P. Kumar, A. Mandal, A. Roy, C. Bieth, S. Kantas, and P. Sortais, Rev. Sci. Instrum. 77, 03A317 (2006)]. The ion beam extracted from the source is decelerated close to the location of a mesh which is polarized to the source potential and beams having different plasma potentials are measured on a Faraday cup located downstream of the mesh. The influence of various source parameters, viz., RF power, gas pressure, magnetic field, negative dc bias, and gas mixing on the plasma potential is studied. The study helped to find an upper limit of the energy spread of the heavy ions, which can influence the design of the longitudinal optics of the high current injector being developed at the Inter University Accelerator Centre. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimizes at an optimum value of the gas pressure of the mixing gas and the mean charge state maximizes at this value. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.

  4. Effect of source tuning parameters on the plasma potential of heavy ions in the 18 GHz high temperature superconducting electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Rodrigues, G.; Baskaran, R.; Kukrety, S.; Mathur, Y.; Kumar, Sarvesh; Mandal, A.; Kanjilal, D.; Roy, A.

    2012-03-01

    Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz high temperature superconducting ECR ion source, PKDELIS [C. Bieth, S. Kantas, P. Sortais, D. Kanjilal, G. Rodrigues, S. Milward, S. Harrison, and R. McMahon, Nucl. Instrum. Methods B 235, 498 (2005), 10.1016/j.nimb.2005.03.232; D. Kanjilal, G. Rodrigues, P. Kumar, A. Mandal, A. Roy, C. Bieth, S. Kantas, and P. Sortais, Rev. Sci. Instrum. 77, 03A317 (2006), 10.1063/1.2164887]. The ion beam extracted from the source is decelerated close to the location of a mesh which is polarized to the source potential and beams having different plasma potentials are measured on a Faraday cup located downstream of the mesh. The influence of various source parameters, viz., RF power, gas pressure, magnetic field, negative dc bias, and gas mixing on the plasma potential is studied. The study helped to find an upper limit of the energy spread of the heavy ions, which can influence the design of the longitudinal optics of the high current injector being developed at the Inter University Accelerator Centre. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimizes at an optimum value of the gas pressure of the mixing gas and the mean charge state maximizes at this value. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.

  5. Effect of source tuning parameters on the plasma potential of heavy ions in the 18 GHz high temperature superconducting electron cyclotron resonance ion source

    SciTech Connect

    Rodrigues, G.; Mathur, Y.; Kumar, Sarvesh; Mandal, A.; Kanjilal, D.; Roy, A.; Baskaran, R.; Kukrety, S.

    2012-03-15

    Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz high temperature superconducting ECR ion source, PKDELIS [C. Bieth, S. Kantas, P. Sortais, D. Kanjilal, G. Rodrigues, S. Milward, S. Harrison, and R. McMahon, Nucl. Instrum. Methods B 235, 498 (2005); D. Kanjilal, G. Rodrigues, P. Kumar, A. Mandal, A. Roy, C. Bieth, S. Kantas, and P. Sortais, Rev. Sci. Instrum. 77, 03A317 (2006)]. The ion beam extracted from the source is decelerated close to the location of a mesh which is polarized to the source potential and beams having different plasma potentials are measured on a Faraday cup located downstream of the mesh. The influence of various source parameters, viz., RF power, gas pressure, magnetic field, negative dc bias, and gas mixing on the plasma potential is studied. The study helped to find an upper limit of the energy spread of the heavy ions, which can influence the design of the longitudinal optics of the high current injector being developed at the Inter University Accelerator Centre. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimizes at an optimum value of the gas pressure of the mixing gas and the mean charge state maximizes at this value. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.

  6. High temperature power electronics for space

    NASA Technical Reports Server (NTRS)

    Hammoud, Ahmad N.; Baumann, Eric D.; Myers, Ira T.; Overton, Eric

    1991-01-01

    A high temperature electronics program at NASA Lewis Research Center focuses on dielectric and insulating materials research, development and testing of high temperature power components, and integration of the developed components and devices into a demonstrable 200 C power system, such as inverter. An overview of the program and a description of the in-house high temperature facilities along with experimental data obtained on high temperature materials are presented.

  7. A high-power X-band Butler matrix

    NASA Astrophysics Data System (ADS)

    Levy, R.

    1984-04-01

    A Butler matrix or array is an antenna beam-forming network using a combination of hybrids and fixed phase shifters. The Butler matrix has the property that a signal incident at each input port provides equal amplitude signals at the N output ports. The present investigation is concerned with the feasibility of constructing a Butler matrix in X-band, using a rectangular waveguide to obtain high peak power capability. The considered design and development program consists of two phases. In phase one, prior to building the actual matrix, a computer analysis of the microwave circuit was conducted, and studies of physical configurations and the associated mechanical problems were performed. Phase two involved the design, construction, and testing of an eight-element Butler matrix for the 9.5-10.0 GHz band. Attention is given to synthesis and analysis theory, a high-power phasor problem solution, the analysis of Butler matrices with imperfect components, physical layouts, and aspects of manufacture, assembly, tuning, and testing.

  8. High Power Klystrons for Efficient Reliable High Power Amplifiers.

    DTIC Science & Technology

    1980-11-01

    components of the space charge waves in the electron beam of a microwave tube are combined to produce more highly concentrated electron bunches raising the...the drift lengths to enhance the 2nd harmonic component in the space charge waves . The latter method was utilized in the VKC-7790. Computer...photographs, operating/ maintanance instructions, layout drawings/schematics and the purchase specification are included, in the above order, in

  9. High power plasma spraying of oxide ceramics

    SciTech Connect

    Lugscheider, E.; Jungklaus, H.; Schwier, G.; Mathesius, H.; Heinrich, P.

    1995-12-31

    New developed high power plasma spray (HPPS) systems offer opportunities for generating both high thermal as well as high kinetic energy transfer to the powder particles. The operation level can be elevated up to 250 kW for continuous processing. PLCs and mass flow controls support high power processing under production conditions. The process is designed for applying large quantities even of high melt materials, such as oxide ceramics. High power plasma processing may result in enhanced coating characteristics. The work in this paper shows first conclusions for processing commercial powders such as alumina, alumina-titania, chromia and a recently developed multicomponent oxide with a HPPS system. Particle velocities were measured after optimizing spraying parameters. Coatings were evaluated by optical microscopy (microstructure and porosity), microhardness and pin-on-disc abrasive wear tests. Powder types and sizes as well as the systems configuration are considered for a general discussion of the capability and limitation in high power plasma spraying.

  10. High power diode lasers reliability experiment

    NASA Astrophysics Data System (ADS)

    Lu, Guoguang; Xie, Shaofeng; Hao, Mingming; Huang, Yun; En, Yunfei

    2013-12-01

    In order to evaluate and obtain the actual lifetime data of high power laser diodes, an automated high power laser diodes reliability experiment was developed and reported in this paper. This computer controlled setup operates the laser diodes 24 hours a day, the parameters such as output power, wavelength were test once in one hour. The experiment has 60 work stations, the temperature control range is from 25°C to 70°C, and the output power of the aging device is beyond 20W.

  11. Terahertz quantum-cascade lasers as high-power and wideband, gapless sources for spectroscopy.

    PubMed

    Röben, Benjamin; Lü, Xiang; Hempel, Martin; Biermann, Klaus; Schrottke, Lutz; Grahn, Holger T

    2017-07-10

    Terahertz (THz) quantum-cascade lasers (QCLs) are powerful radiation sources for high-resolution and high-sensitivity spectroscopy with a discrete spectrum between 2 and 5 THz as well as a continuous coverage of several GHz. However, for many applications, a radiation source with a continuous coverage of a substantially larger frequency range is required. We employed a multi-mode THz QCL operated with a fast ramped injection current, which leads to a collective tuning of equally-spaced Fabry-Pérot laser modes exceeding their separation. A continuous coverage over 72 GHz at about 4.7 THz was achieved. We demonstrate that the QCL is superior to conventional sources used in Fourier transform infrared spectroscopy in terms of the signal-to-noise ratio as well as the dynamic range by one to two orders of magnitude. Our results pave the way for versatile THz spectroscopic systems with unprecedented resolution and sensitivity across a wide frequency range.

  12. Behavior of an inversion-based precipitation retrieval algorithm with high-resolution AMPR measurements including a low-frequency 10.7-GHz channel

    NASA Technical Reports Server (NTRS)

    Smith, E. A.; Xiang, X.; Mugnai, A.; Hood, R. E.; Spencer, R. W.

    1994-01-01

    A microwave-based, profile-type precipitation retrieval algorithm has been used to analyze high-resolution passsive microwave measurements over an ocean background, obtained by the Advanced Microwave Precipitation Radiometer (AMPR) flown on a NASA ER-2 aircraft. The analysis is designed to first determine the improvements that can be gained by adding brightness temperature information from the AMPR low-frequency channel (10.7 GHz) to a multispectral retrieval algorithm nominally run with satellite information at 19, 37, and 85 GHz. The impact of spatial resolution degradation of the high-resolution brightness temperature information on the retrieved rain/cloud liquid water contents and ice water contents is then quantified in order to assess the possible biases inherent to satellite-based retrieval. Careful inspection of the high-resolution aircraft dataset reveals five distinctive brightness temperature features associated with cloud structure and scattering effects that are not generally detectable in current passive microwave satellite measurements. Results suggest that the inclusion of 10.7-GHz information overcomes two basic problems associated with three-channel retrieval. Intercomparisons of retrievals carried out at high-resolution and then averaged to a characteristic satellite scale to the corresponding retrievals in which the brightness temperatures are first convolved down to the satellite scale suggest that with the addition of the 10.7-GHz channel, the rain liquid water contents will not be negatively impacted by special resolution degradation. That is not the case with the ice water contents as they appear ti be quite sensitive to the imposed scale, the implication being that as spatial resolution is reduced, ice water contents will become increasingly underestimated.

  13. Development of gallium arsenide high-speed, low-power serial parallel interface modules: Executive summary

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Final report to NASA LeRC on the development of gallium arsenide (GaAS) high-speed, low power serial/parallel interface modules. The report discusses the development and test of a family of 16, 32 and 64 bit parallel to serial and serial to parallel integrated circuits using a self aligned gate MESFET technology developed at the Honeywell Sensors and Signal Processing Laboratory. Lab testing demonstrated 1.3 GHz clock rates at a power of 300 mW. This work was accomplished under contract number NAS3-24676.

  14. High power solid state switches

    NASA Astrophysics Data System (ADS)

    Gundersen, Martin

    1991-11-01

    We have successfully produced an optically triggered thyristor based in Gallium Arsenide, developed a model for breakdown, and are developing two related devices, including a Gallium Arsenide based static inductor thyristor. We are getting at the basic limitations of Gallium Arsenide for these applications, and are developing models for the physical processes that will determine device limitations. The previously supported gas phase work - resulting in the back-lighted thyratron (BLT) - has actually resulted in a very changed view of how switching can be accomplished, and this is impacting the design of important machines. The BLT is being studied internationally: in Japan for laser fusion and laser isotope separation. ITT has built a BLT that has switched 30 kA at 60 kV in testing at NSWC Dahlgren and the device is being commercialized by another American company. Versions of the switch are now being tested for excimer laser and other applications. Basically, the switch, which arose from pulse power physics studies at USC, can switch more current faster (higher di/dt), with less housekeeping, and with other advantageous properties. There are a large number of other new applications, include kinetic energy weapons, pulsed microwave sources and R.F. accelerators.

  15. High-Temperature Passive Power Electronics

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In many future NASA missions - such as deep-space exploration, the National AeroSpace Plane, minisatellites, integrated engine electronics, and ion or arcjet thrusters - high-power electrical components and systems must operate reliably and efficiently in high-temperature environments. The high-temperature power electronics program at the NASA Lewis Research Center focuses on dielectric and insulating material research, the development and characterization of high-temperature components, and the integration of the developed components into a demonstrable 200 C power system - such as an inverter. NASA Lewis has developed high-temperature power components through collaborative efforts with the Air Force Wright Laboratory, Northrop Grumman, and the University of Wisconsin. Ceramic and film capacitors, molypermalloy powder inductors, and a coaxially wound transformer were designed, developed, and evaluated for high-temperature operation.

  16. The 30-GHz monolithic receive module

    NASA Technical Reports Server (NTRS)

    Sokolov, V.; Geddes, J.; Bauhahn, P.

    1983-01-01

    Key requirements for a 30 GHz GaAs monolithic receive module for spaceborne communication antenna feed array applications include an overall receive module noise figure of 5 dB, a 30 dB RF to IF gain with six levels of intermediate gain control, a five-bit phase shifter, and a maximum power consumption of 250 mW. The RF designs for each of the four submodules (low noise amplifier, some gain control, phase shifter, and RF to IF sub-module) are presented. Except for the phase shifter, high frequency, low noise FETs with sub-half micron gate lengths are employed in the submodules. For the gain control, a two stage dual gate FET amplifier is used. The phase shifter is of the passive switched line type and consists of 5-bits. It uses relatively large gate width FETs (with zero drain to source bias) as the switching elements. A 20 GHz local oscillator buffer amplifier, a FET compatible balanced mixer, and a 5-8 GHz IF amplifier constitute the RF/IF sub-module. Phase shifter fabrication using ion implantation and a self-aligned gate technique is described. Preliminary RF results obtained on such phase shifters are included.

  17. Design and cold testing of a high peak power x-band gyroklystron

    SciTech Connect

    Lawson, W.; Calame, J.; Granatstein, V.L.; Latham, P.E.; McAdoo, J.; Park, G.S.; Striffler, C.D.; Williams, F.J.; Chu, K.R.; Seftor, J.L.

    1985-01-01

    The main goal of the University of Maryland's gyroklystron project is to develop an efficient, high power, high gain, phase controllable amplifier at 10 GHz. While peak powers of several hundred megawatts are ultimately of interest, our initial experimental design values include 30 MW of output power in 1 ..mu..s pulses with a gain in excess of 50 dB. The 30 MW power level represents an enhancement of almost three orders of magnitude over the current state-of-the-art in gyroklystron amplifiers. This enhancement will be achieved by going to high beam energies (..gamma..approx. =2) and overmoded cavities (TE/sub 01//sup 0/). Outlined in this report are the steps being taken to realize our goal.

  18. High power ultrashort pulse lasers

    SciTech Connect

    Perry, M.D.

    1994-10-07

    Small scale terawatt and soon even petawatt (1000 terawatt) class laser systems are made possible by application of the chirped-pulse amplification technique to solid-state lasers combined with the availability of broad bandwidth materials. These lasers make possible a new class of high gradient accelerators based on the large electric fields associated with intense laser-plasma interactions or from the intense laser field directly. Here, we concentrate on the laser technology to produce these intense pulses. Application of the smallest of these systems to the production of high brightness electron sources is also introduced.

  19. NASA developments in solid state power amplifiers

    NASA Technical Reports Server (NTRS)

    Leonard, Regis F.

    1990-01-01

    Over the last ten years, NASA has undertaken an extensive program aimed at development of solid state power amplifiers for space applications. Historically, the program may be divided into three phases. The first efforts were carried out in support of the advanced communications technology satellite (ACTS) program, which is developing an experimental version of a Ka-band commercial communications system. These first amplifiers attempted to use hybrid technology. The second phase was still targeted at ACTS frequencies, but concentrated on monolithic implementations, while the current, third phase, is a monolithic effort that focusses on frequencies appropriate for other NASA programs and stresses amplifier efficiency. The topics covered include: (1) 20 GHz hybrid amplifiers; (2) 20 GHz monolithic MESFET power amplifiers; (3) Texas Instruments' (TI) 20 GHz variable power amplifier; (4) TI 20 GHz high power amplifier; (5) high efficiency monolithic power amplifiers; (6) GHz high efficiency variable power amplifier; (7) TI 32 GHz monolithic power amplifier performance; (8) design goals for Hughes' 32 GHz variable power amplifier; and (9) performance goals for Hughes' pseudomorphic 60 GHz power amplifier.

  20. Systematic Observation of Time-Dependent Phenomena in the RF Output Spectrum of High Power Gyrotrons

    NASA Astrophysics Data System (ADS)

    Schlaich, Andreas; Gantenbein, Gerd; Kern, Stefan; Thumm, Manfred

    2012-09-01

    At IHM/KIT, high power gyrotrons with conventional cavity (e.g. 1 MW CW at 140 GHz for the stellarator Wendelstein 7-X) and coaxial cavity (2 MW shortpulse at 170 GHz for ITER) for fusion applications are being developed and verified experimentally. Especially with respect to the problem of parasitic RF oscillations in the beam tunnel of some W7-X tubes, investigations of the gyrotron RF output spectrum have proved to be a valuable source of diagnostic information. Signs of transient effects in millisecond pulses, like frequency switching or intermittent low-frequency modulation, have indicated that truly time-dependent measurements with high frequency resolution and dynamic range could give deeper insight into these phenomena. In this paper, an improved measurement system is presented, which employs a fast oscilloscope as receiver. Shorttime Fourier transform (STFT) is applied to the time-domain signal, yielding time-variant spectra with frequency resolutions only limited by acquisition length and STFT segmentation choice. Typical reasonable resolutions are in the range of 100 kHz to 10 MHz with a currently memory-limited maximum acquisition length of 4 ms. A key feature of the system consists in the unambiguity of frequency measurement: The system receives through two parallel channels, each using a harmonic mixer (h = 9 - 12) to convert the signal from RF millimeter wave frequencies (full D-Band, 110 - 170 GHz) to IF (0 - 3 GHz). For each IF output signal of each individual mixer, injection side and receiving harmonic are initially not known. Using accordingly determined LO frequencies, this information is retrieved from the redundancy of the channels, yielding unambiguously reconstructed RF spectra with a total span of twice the usable receiver IF bandwidth, up to ≈ 6 GHz in our case. Using the system, which is still being improved continuously, various transient effects like cavity mode switching, parasitic oscillation frequency variation, and lowfrequency

  1. High-power picosecond laser pulse recirculation.

    PubMed

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-01

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high-power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering-based light sources. We demonstrate up to 40x average power enhancement of frequency-doubled submillijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  2. High Power Picosecond Laser Pulse Recirculation

    SciTech Connect

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

    2010-04-12

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  3. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS.

    SciTech Connect

    BEN-ZVI, ILAN, DAYRAN, D.; LITVINENKO, V.

    2005-08-21

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department.

  4. High-efficiency solid state power amplifier

    NASA Technical Reports Server (NTRS)

    Wallis, Robert E. (Inventor); Cheng, Sheng (Inventor)

    2005-01-01

    A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

  5. High voltage photovoltaic power converter

    DOEpatents

    Haigh, Ronald E.; Wojtczuk, Steve; Jacobson, Gerard F.; Hagans, Karla G.

    2001-01-01

    An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

  6. High-power lasers for directed-energy applications: comment.

    PubMed

    Vorontsov, Mikhail A; Weyrauch, Thomas

    2016-12-10

    Sprangle et al. [Appl. Opt.54, F201 (2015)APOPAI0003-693510.1364/AO.54.00F201] recently concluded that our experiments on coherent combining of laser beams over an atmospheric path [Opt. Lett.36, 4455 (2011)OPLEDP0146-959210.1364/OL.36.004455] were "effective only because at these low-power levels the linewidth of the lasers was very narrow… and the level of atmospheric turbulence was low…." These conclusions are inaccurate, not relevant to practical high-power coherently combined laser systems, and contradict our most recent experiments with coherent combining of 21 laser beams with a linewidth of about 1 GHz over 7 km distance. In this comment we also challenge the major conclusion of Sprangle et al. [Appl. Opt.54, F201 (2015)APOPAI0003-693510.1364/AO.54.00F201] and the more recently published paper by Nelson et al. [Appl. Opt.55, 1757 (2016)APOPAI0003-693510.1364/AO.55.001757] regarding inefficiency of coherent beam combining under typical atmospheric conditions.

  7. K-band high power latching switch. [communication satellite system

    NASA Technical Reports Server (NTRS)

    Mlinar, M. J.; Piotrowski, W. S.; Raue, J. E.

    1980-01-01

    A 19 GHz waveguide latching switch with a bandwidth of 1400 MHz and an exceptionally low insertion loss of 0.25 dB was demonstrated. The RF and driver ferrites are separate structures and can be optimized individually. This analysis for each structure is separately detailed. Basically, the RF section features a dual turnstile junction. The circulator consists of a dielectric tube which contains two ferrite rods, and a dielectric spacer separating the ferrite parts along the center of symmetry of the waveguide to form two turnstiles. This subassembly is indexed and locked in the center of symmetry of a uniform junction of three waveguides by the metallic transformers installed in the top and bottom walls of the housing. The switching junction and its actuating circuitry met all RF performance objectives and all shock and vibration requirements with no physical damage or performance degradation. It exceeds thermal requirements by operating over a 100 C temperature range (-44 C to +56 C) and has a high power handling capability allowing up to 100 W of CW input power.

  8. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method

    SciTech Connect

    Qiu, Jiaqi; Zhu, Yimei; Ha, Gwanghui; Jing, Chunguang; Baryshev, Sergey V.; Reed, Bryan W.; Lau, June W.

    2015-11-10

    In this study, a device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1 GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incoming dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges.

  9. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method

    DOE PAGES

    Qiu, Jiaqi; Zhu, Yimei; Ha, Gwanghui; ...

    2015-11-10

    In this study, a device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1 GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incomingmore » dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges.« less

  10. High-power red VCSEL arrays

    NASA Astrophysics Data System (ADS)

    Seurin, Jean-Francois; Khalfin, Viktor; Xu, Guoyang; Miglo, Alexander; Li, Daizong; Zhou, Delai; Sundaresh, Mukta; Zou, Wei-Xiong; Lu, Chien-Yao; Wynn, James D.; Ghosh, Chuni

    2013-03-01

    High-power red laser sources are used in many applications such as cosmetics, cancer photodynamic therapy, and DNA sequencing in the medical field, laser-based RGB projection display, and bar-code scanning to name a few. Verticalcavity surface-emitting lasers (VCSELs) can be used as high-power laser sources, as efficient single devices can be configured into high-power two-dimensional arrays and scaled into modules of arrays. VCSELs emit in a circular, uniform beam which can greatly reduce the complexity and cost of optics. Other advantages include a narrow and stable emission spectrum, low speckle of the far-field emission, and good reliability. However, developing efficient red VCSEL sources presents some challenges because of the reduced quantum-well carrier confinement and the increased Aluminum content (to avoid absorption) which increases thermal impedance, and also decreases the DBR index contrast resulting in increased penetration length and cavity losses. We have recently developed VCSEL devices lasing in the visible 6xx nm wavelength band, and reaching 30% power conversion efficiency. We fabricated high-power 2D arrays by removing the GaAs substrate entirely and soldered the chips on high thermal conductivity submounts. Such arrays have demonstrated several Watts of output power at room temperature, in continuous-wave (CW) operation. Several tens of Watts are obtained in QCW operation. Results and challenges of these high-power visible VCSEL arrays will be discussed.

  11. Operation and performance analyses of 350 and 700 MHz low-/high-temperature superconductor nuclear magnetic resonance magnets: A march toward operating frequencies above 1 GHz

    NASA Astrophysics Data System (ADS)

    Hahn, Seungyong; Bascuñán, Juan; Lee, Haigun; Bobrov, Emanuel S.; Kim, Wooseok; Ahn, Min Cheol; Iwasa, Yukikazu

    2009-01-01

    Since 2000, a three-phase program with a final goal to complete a 1 GHz high-resolution low-/high-temperature superconductor (LTS/HTS) nuclear magnetic resonance (NMR) magnet has been conducted at the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology (MIT). In a LTS/HTS magnet assembly, a HTS insert is placed in the cold bore of a LTS background magnet. To date, two LTS/HTS magnets have been designed, constructed, and tested: a 350 MHz (LH350) in phase 1 and a 700 MHz (LH700) in phase 2. The program's target has recently been upgraded from the original goal of 1 GHz to a new goal of 1.3 GHz. In this paper, we present extensive performance analyses of the two LTS/HTS NMR magnets. Spatial homogeneity and temporal stability of LH350 and LH700, examined with harmonic analysis, and four key issues that became evident in the operation of these two magnets are discussed: (1) field constant reduction, (2) "large" residual Z1 gradient and its temporal decay, (3) large one-periodic tesseral field gradients, and (4) screening-current-induced field in the HTS inserts.

  12. High Power Amplifier Harmonic Output Level Measurement

    NASA Technical Reports Server (NTRS)

    Perez, R. M.; Hoppe, D. J.; Khan, A. R.

    1995-01-01

    A method is presented for the measurement of the harmonic output power of high power klystron amplifiers, involving coherent hemispherical radiation pattern measurements of the radiated klystron output. Results are discussed for the operation in saturated and unsaturated conditions, and with a waveguide harmonic filter included.

  13. High Power Amplifier Harmonic Output Level Measurement

    NASA Technical Reports Server (NTRS)

    Perez, R. M.; Hoppe, D. J.; Khan, A. R.

    1995-01-01

    A method is presented for the measurement of the harmonic output power of high power klystron amplifiers, involving coherent hemispherical radiation pattern measurements of the radiated klystron output. Results are discussed for the operation in saturated and unsaturated conditions, and with a waveguide harmonic filter included.

  14. 100 GHz, 1 MW, CW gyrotron study program. Final report

    SciTech Connect

    Felch, K.; Bier, R.; Caplan, M.; Jory, H.

    1983-09-01

    The results of a study program to investigate the feasibility of various approaches in designing a 100 GHz, 1 MW CW gyrotron are presented. A summary is given of the possible configurations for a high average power, high frequency gyrotron, including an historical survey of experimental results which are relevant to the various approaches. A set of basic scaling considerations which enable qualitative comparisons between particular gyrotron interaction circuits is presented. These calculations are important in understanding the role of various electron beam and circuit parameters in achieving a viable gyrotron design. Following these scaling exercises, a series of design calculations is presented for a possible approach in achieving 100 GHz, 1 MW CW. These calculations include analyses of the electron gun and interaction circuit parts of the gyrotron, and a general analysis of other aspects of a high average power, high frequency gyrotron. Scalability of important aspects of the design to other frequencies is also discussed, as well as key technology issues.

  15. High-resolution maps of the 1.5 GHz emission from Jupiter's disk and radiation belt

    NASA Technical Reports Server (NTRS)

    Roberts, J. A.; Berge, G. L.; Bignell, R. C.

    1984-01-01

    VLA maps of four different faces of Jupiter made with a resolution of about 0.3 Jovian radius show new features of the radiation belt emission. A synchrotron model which reproduces these features serves to define the major characteristics of the relativistic electrons in the radiation belt. The observations provide the best determination to date of the atmospheric emission at 1.5 GHz and yield a disk brightness temperature of 425 + or - 100 K.

  16. Optical power splitter for splitting high power light

    DOEpatents

    English, R.E. Jr.; Christensen, J.J.

    1995-04-18

    An optical power splitter for the distribution of high-power light energy has a plurality of prisms arranged about a central axis to form a central channel. The input faces of the prisms are in a common plane which is substantially perpendicular to the central axis. A beam of light which is substantially coaxial to the central axis is incident on the prisms and at least partially strikes a surface area of each prism input face. The incident beam also partially passes through the central channel. 5 figs.

  17. Optical power splitter for splitting high power light

    DOEpatents

    English, Jr., Ronald E.; Christensen, John J.

    1995-01-01

    An optical power splitter for the distribution of high-power light energy has a plurality of prisms arranged about a central axis to form a central channel. The input faces of the prisms are in a common plane which is substantially perpendicular to the central axis. A beam of light which is substantially coaxial to the central axis is incident on the prisms and at least partially strikes a surface area of each prism input face. The incident beam also partially passes through the central channel.

  18. All solid-state high power microwave source with high repetition frequency.

    PubMed

    Bragg, J-W B; Sullivan, W W; Mauch, D; Neuber, A A; Dickens, J C

    2013-05-01

    An all solid-state, megawatt-class high power microwave system featuring a silicon carbide (SiC) photoconductive semiconductor switch (PCSS) and a ferrimagnetic-based, coaxial nonlinear transmission line (NLTL) is presented. A 1.62 cm(2), 50 kV 4H-SiC PCSS is hard-switched to produce electrical pulses with 7 ns full width-half max (FWHM) pulse widths at 2 ns risetimes in single shot and burst-mode operation. The PCSS resistance drops to sub-ohm when illuminated with approximately 3 mJ of laser energy at 355 nm (tripled Nd:YAG) in a single pulse. Utilizing a fiber optic based optical delivery system, a laser pulse train of four 7 ns (FWHM) signals was generated at 65 MHz repetition frequency. The resulting electrical pulse train from the PCSS closely follows the optical input and is utilized to feed the NLTL generating microwave pulses with a base microwave-frequency of about 2.1 GHz at 65 MHz pulse repetition frequency (prf). Under typical experimental conditions, the NLTL produces sharpened output risetimes of 120 ps and microwave oscillations at 2-4 GHz that are generated due to damped gyromagnetic precession of the ferrimagnetic material's axially pre-biased magnetic moments. The complete system is discussed in detail with its output matched into 50 Ω, and results covering MHz-prf in burst-mode operation as well as frequency agility in single shot operation are discussed.

  19. All solid-state high power microwave source with high repetition frequency

    NASA Astrophysics Data System (ADS)

    Bragg, J.-W. B.; Sullivan, W. W.; Mauch, D.; Neuber, A. A.; Dickens, J. C.

    2013-05-01

    An all solid-state, megawatt-class high power microwave system featuring a silicon carbide (SiC) photoconductive semiconductor switch (PCSS) and a ferrimagnetic-based, coaxial nonlinear transmission line (NLTL) is presented. A 1.62 cm2, 50 kV 4H-SiC PCSS is hard-switched to produce electrical pulses with 7 ns full width-half max (FWHM) pulse widths at 2 ns risetimes in single shot and burst-mode operation. The PCSS resistance drops to sub-ohm when illuminated with approximately 3 mJ of laser energy at 355 nm (tripled Nd:YAG) in a single pulse. Utilizing a fiber optic based optical delivery system, a laser pulse train of four 7 ns (FWHM) signals was generated at 65 MHz repetition frequency. The resulting electrical pulse train from the PCSS closely follows the optical input and is utilized to feed the NLTL generating microwave pulses with a base microwave-frequency of about 2.1 GHz at 65 MHz pulse repetition frequency (prf). Under typical experimental conditions, the NLTL produces sharpened output risetimes of 120 ps and microwave oscillations at 2-4 GHz that are generated due to damped gyromagnetic precession of the ferrimagnetic material's axially pre-biased magnetic moments. The complete system is discussed in detail with its output matched into 50 Ω, and results covering MHz-prf in burst-mode operation as well as frequency agility in single shot operation are discussed.

  20. Ka-Band TWT High-Efficiency Power Combiner for High-Rate Data Transmission

    NASA Technical Reports Server (NTRS)

    Wintucky, Edwin G.; Simons, Rainee; Vaden, Karl R.; Lesny, Gary G.; Glass, Jeffrey L.

    2007-01-01

    A four-port magic-T hybrid waveguide junction serves as the central component of a high-efficiency two-way power combiner circuit for transmitting a high-rate phase-modulated digital signal at a carrier frequency in the Ka-band (between 27 and 40 GHz). This power combiner was developed to satisfy a specific requirement to efficiently combine the coherent outputs of two traveling-wavetube (TWT) amplifiers that are typically characterized by power levels on the order of 100 W or more. In this application, the use of a waveguide-based power combiner (instead of a coaxial-cable- or microstrip-based power combiner, for example) is dictated by requirements for low loss, high power-handling capability, and broadband response. Combiner efficiencies were typically 90 percent or more over both the linear and saturated output power regions of operation of the TWTs . Figure 1 depicts the basic configuration of the magic-T hybrid junction. The coherent outputs of the two TWTs enter through ports 1 and 4. As a result of the orientations of the electromagnetic fields, which also provides a needed high port-to-port isolation, of these two input signals and the interior design of the magic-T junction, the input powers are divided so as to add in phase at one output port (port 2), and to be opposite in phase and hence cancel each other at the opposite coplanar output port (port 3). The net result is that the output power at port 2 is essentially double that of the output of one TWT, minus the power lost in the magic-T hybrid junction. Optimum performance as a high-efficiency power combiner thus requires a balance of both power and phase at the input ports of the magic-T. Replicas of this two-way combiner can be arranged in a binary configuration to obtain a 2n-way (where n is an integer) combiner. For example, Figure 2 illustrates the use of three two-way combiners to combine the outputs of four TWTs.