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  • ELECTRONICS AND ELECTRICAL ENGINEERING  (306)
  • 1990-1994  (306)
  • 1991  (306)
  • 1
    Publication Date: 2011-12-09
    Description: Microstrip ring resonators operating at 35 GHz were fabricated from laser ablated YBCO films deposited on lanthanum aluminate substrates. They were measured over a range of temperatures and their performances compared to identical resonators made of evaporated gold. Below 60 Kelvin the superconducting strip performed better than the gold, reaching an unloaded Q approximately 1.5 times that of gold at 25 K. A shift in the resonant frequency follows the form predicted by the London equations. The Phenomenological Loss Equivalence Method is applied to the ring resonator and the theoretically calculated Q values are compared to the experimental results.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Microwave Theory and Techniques (ISSN 0018-9480); 39; 1480-148
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  • 2
    Publication Date: 2011-12-09
    Description: A chemical vapor deposition (CVD) process has been used to produce device structures of n- and p-type 6H-SiC epitaxial layers on commercially produced single-crystal 6H-SiC wafers. Mesa-style p-n junction diodes were successfully fabricated from these device structures using reactive ion etching, oxide passivation, and electrical contact metallization techniques. When tested in air, the 6H-SiC diodes displayed excellent rectification characteristics up to the highest temperature tested, 600 C. To observe avalanche breakdown of the p-n junction diodes, testing under a high-electrical-strength liquid was necessary. The avalanche breakdown voltage was 1000 V representing the highest reverse breakdown voltage to be reported for any CVD-grown SiC diode.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 59; 1770-177
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  • 3
    Publication Date: 2011-12-09
    Description: Two new coplanar waveguide to rectangular waveguide couplers with coupling through a post and a slot are experimentally demonstrated. The couplers operate over the Ku-band transmission and X-band reception frequencies that are designated for satellite communications. The measured insertion loss and return loss are about 1 dB, respectively, for both couplers.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electronics Letters (ISSN 0013-5194); 27; 856-858
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  • 4
    Publication Date: 2011-08-24
    Description: We describe the fabrication and characterization of superconductor/normal metal/superconductor (SNS) devices made with the high-temperature superconductor (HTS) YBa2Cu3O(7-x). Structures of YBa2Cu3O(7-x)/Au/Nb on c-axis-oriented YBa2Cu3O(7-x) were made in both sandwich and edge geometries in order to sample the HTS material both along and perpendicular to the conducting a-b planes. These devices display fairly ideal Josephson properties at 4.2 K. In addition, devices consisting of YBa2Cu3O(7-x)/YBa2Cu3O(y)/YBa2Cu3O(7-x), with a 'normal metal' layer of reduced transition temperature YBa2Cu3O(7-x) were fabricated and show a great deal of promise for applications near 77 K. Current-voltage characteristics like those of the Resistively-Shunted Junction model are observed, with strong response to 10 GHz radiation above 60 K.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Superconductivity applications for infrared and microwave devices II; Proceedings of the Meeting, Orlando, FL, Apr. 4, 5, 1991 (A93-27243 09-33); p. 192-196.
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  • 5
    Publication Date: 2011-08-24
    Description: Thin film low-pass microwave filters have been made with laser-ablated YBa2Cu3O(7-delta) (YBCO) deposited on LaAlO3 substrates, using a coplanar waveguide structure. The coplanar waveguide sections had dimensions suited for integrated circuits. Measured losses in liquid nitrogen were superior to the loss in a similar thin-film copper filter throughout the 0 to 9.5 GHz pass-band. A simple transmission-line model is adequate for filter design using YBCO films with repeatable characteristics. The measured filters demonstrate the performance of fully patterned YBCO after sealing in space-qualifiable hermetic packages. Five packaged filters of this design were delivered to the Naval Research Laboratory as candidates for space flight in the High Temperature Superconductivity Space Experiment.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Superconductivity applications for infrared and microwave devices II; Proceedings of the Meeting, Orlando, FL, Apr. 4, 5, 1991 (A93-27243 09-33); p. 95-100.
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  • 6
    Publication Date: 2011-08-24
    Description: 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.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: ; : Computational meth
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  • 7
    Publication Date: 2011-08-24
    Description: A proposed Ka-band communications experiment between the Shuttle Orbiter and the Advanced Communications Technology Satellite (ACTS) is described. Monolithic Microwave Integrated Circuit (MMIC) technology is used in both the Orbiter and on the ground. A 25 dB gain circularly polarized phased array transmits low-bit-rate television to ground stations at the Johnson Space Center and the Lewis Research Center.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Monolithic microwave integrated circuits for sensors, radar, and communications systems; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991 (A93-25776 09-33); p. 231-242.
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  • 8
    Publication Date: 2011-08-24
    Description: Capabilities and limitations of MMIC phase shifter technology at microwave and millimeter wave frequencies are reviewed. MMIC-based phase arrays make it possible to integrate active elements at the array face, i.e., to incorporate transmit power amplifiers and/or low noise amplifiers at each antenna element. Active elements make it possible to increase power efficiency and reliability and provide graceful degradation. Monolithic integration of the various transmit/receive functions including phase shifting is considered to be feasible through at least the lower millimeter-wave frequency range (about 30-100 GHz). MMIC integration also allows more flexibility in array design including those that are intended for airborne conformal applications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Monolithic microwave integrated circuits for sensors, radar, and communications systems; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991 (A93-25776 09-33); p. 288-302.
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  • 9
    Publication Date: 2011-08-24
    Description: Ka-band MMIC transmitter arrays are under development at NASA Jet Propulsion Laboratory for future deep space and ground communication needs. A high efficiency full aperture active antenna array is desired to demonstrate solid state array technology for future NASA missions. This paper reports on a 5 watt Ka-band phased array feed and a full aperture active array for a mobile terminal which are being developed to characterize the design tradeoffs and potential of solid state Ka-band MMIC array communication systems.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Monolithic microwave integrated circuits for sensors, radar, and communications systems; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991 (A93-25776 09-33); p. 243-247.
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  • 10
    Publication Date: 2011-08-24
    Description: Approaches for future 'mixed application' monolithic integrated circuits (ICs) employing optical receive/transmit, RF amplification and modulation and digital control functions are discussed. We focus on compatibility of the photonic component fabrication with conventional RF and digital IC technologies. Recent progress at Honeywell in integrating several parts of the desired RF/digital/photonic circuit integration suite required for construction of a future millimeter-wave optically-controlled phased-array element are illustrated.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Monolithic microwave integrated circuits for sensors, radar, and communications systems; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991 (A93-25776 09-33); p. 223-230.
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  • 11
    Publication Date: 2011-08-24
    Description: Recent advances in pseudomorphic HEMT MMIC (PMHEMT/MMIC) technology have made it the preferred candidate for high performance millimeter-wave components for phased array applications. This paper describes the development of PMHEMT/MMIC components at Ka-band and V-band. Specifically, the following PMHEMT/MMIC components will be described: power amplifiers at Ka-band; power amplifiers at V-band; and four-bit phase shifters at V-band. For the Ka-band amplifier, 125 mW output power with 5.5 dB gain and 21 percent power added efficiency at 2 dB compression point has been achieved. For the V-band amplifier, 112 mW output power with 6 dB gain and 26 percent power added efficiency has been achieved. And, for the V-band phase shifter, four-bit (45 deg steps) phase shifters with less than 8 dB insertion loss from 61 GHz to 63 GHz will be described.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Monolithic microwave integrated circuits for sensors, radar, and communications systems; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991 (A93-25776 09-33); p. 184-192.
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  • 12
    Publication Date: 2011-12-09
    Description: Microwave transmission measurements through YBa2Cu3O(7-delta) (YBCO) high-transition-temperature superconducting thin films on lanthanum aluminate (LaAlO3) have been performed in a coaxial line at 10 GHz. LaAlO3 substrates were ultrasonically machined into washer-shaped discs, polished, and coated with laser-ablated YBCO. These samples were mounted in a 50-ohm coaxial air line to form a short circuit. The power transmitted through the films as a function of temperature was used to calculate the normal state conductivity and the magnetic penetration depth for the films.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Applied Superconductivity (ISSN 1051-8223); 1; 178-180
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  • 13
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    In:  CASI
    Publication Date: 2006-06-13
    Description: The goals of this program are to develop custom microcircuit technology, also known as Application Specific Integrated Circuit (ASIC) technology, for use in flight and ground programs. Supporting this effort are activities to investigate the effects of the space environment, and particularly ionizing radiation, on microcircuits and to develop a space qualification methodology. Another aspect of the program emphasizes innovative applications of custom microcircuit technology to image and signal processing and communications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Center for Space Microelectronics Technology; p 83-87
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  • 14
    Publication Date: 2011-08-24
    Description: Post-irradiation effects (PIE) ranging from normal recovery to catastrophic failure have been observed in integrated circuits during the PIE period. Data presented show failure due to rebound after a 10 krad(Si) dose. In particular, five device types are investigated with varying PIE response. Special attention has been given to the HI1-507A analog multiplexer because its PIE response is extreme. X-ray diffraction has been uniquely employed to measure physical stress in the HI1-507A metallization. An attempt has been made to show a relationship between stress relaxation and radiation effects. All data presented support the current MIL-STD Method 1019.4 but demonstrate the importance of performing PIE measurements, even when mission doses are as low as 10 krad(Si).
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); 38; 1584-158
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  • 15
    Publication Date: 2011-08-24
    Description: A methodology is described for predicting the SEU susceptibility of a standard-cell D-latch using an alpha-particle sensitive SRAM, SPICE critical charge simulation results, and alpha-particle interaction physics. Measurements were made on a 1.6-micron n-well CMOS 4-kb test SRAM irradiated with an Am-241 alpha-particle source. A collection depth of 6.09 micron was determined using these results and TRIM computer code. Using this collection depth and SPICE derived critical charge results on the latch design, an LET threshold of 34 MeV sq cm/mg was predicted. Heavy ion tests were then performed on the latch and an LET threshold of 41 MeV sq cm/mg was determined.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); 38; 1486-149
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  • 16
    Publication Date: 2011-08-24
    Description: JPL and the Aerospace Corporation have collected a fourth set of heavy ion single event effects (SEE) test data. Trends in SEE susceptibility (including soft errors and latchup) for state-of-the-art parts are displayed. All data are conveniently divided into two tables: one for MOS devices, and one for a shorter list of recently tested bipolar devices. In addition, a new table of data for latchup tests only (invariably CMOS processes) is given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); 38; 1529-153
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  • 17
    Publication Date: 2011-08-24
    Description: The authors report on the direct detection capabilities of resonant tunneling diodes in the 10-100 GHz range. An open circuit voltage sensitivity of 1750 mV/mW (in Ka-band) was measured. This is higher than the sensitivity of comparatively based commercially available solid-state detectors. The detector properties are a strong function of diode bias and the measured tangential signal sensitivity (-32 dBm at Ka-band with 1-MHz bandwidth) and the dynamic range (25 dB) of the diode are smaller compared to other solid-state detectors.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Microwave Theory and Techniques (ISSN 0018-9480); 39; 1876-188
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  • 18
    Publication Date: 2011-08-24
    Description: The first InGaAs/InP charge-coupled device is demonstrated, exhibiting a charge transfer efficiency (CTE) of 0.98 at 13 MHz and 1 GHz. Cooling the device improves the CTE to greater than 0.99 at 13-MHz clock frequency. The 0.76-eV In(0.53)Ga(0.47)As bandgap makes this structure applicable to direct-detection short-wavelength infrared imagers.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Electron Device Letters (ISSN 0741-3106); 12; 688-690
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  • 19
    Publication Date: 2011-08-24
    Description: A study of persistent, trapped magnetic field has been pursued with high-temperature superconducting (HTS) materials. The main effort is to study the feasibility of utilization of HTS to fabricate magnets for various devices. The trapped field, when not in saturation, is proportional to the applied field. Thus, it should be possible to replicate complicated field configurations with melt-textured YBa2Cu3O7 (MT-Y123) material, bypassing the need for HTS wires. Presently, materials have been developed from which magnets of 1.5 T, at 77 K, can be fabricated. Much higher field is available at lower operating temperature. Stability of a few percent per year is readily attainable. Results of studies on prototype motors and minimagnets are reported.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 70; 6501-650
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  • 20
    Publication Date: 2011-08-24
    Description: A laser diode current driver has been developed for free space laser communications. The driver provides 300 mA peak modulation current and exhibits an optical risetime of less than 400 ps. The current and optical pulses are well behaved and show minimal ringing. The driver is well suited for QPPM modulation at data rates up to 440 Mbit/s. Much previous work has championed current steering circuits; in contrast, the present driver is a single-ended on/off switch. This results in twice the power efficiency as a current steering driver. The driver electrical efficiency for QPPM data is 34 percent. The high speed switch is realized with a Ku-band GaAsFET transistor, with a suitable pre-drive circuit, on a hybrid microcircuit adjacent to the laser diode.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: In: Free-space laser communication technologies III; Proceedings of the Meeting, Los Angeles, CA, Jan. 21, 22, 1991 (A93-18923 05-74); p. 412-420.
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  • 21
    Publication Date: 2011-08-19
    Description: Sandwich geometry superconductor/normal metal/superconductor structures have been fabricated on LaAlO3 and cubic zirconia with laser-ablated, c-axis-oriented YBa2Cu3O(7-delta) base electrodes, 100-600 A of Au, and Nb counter electrodes, all formed in situ without breaking vacuum. Junctions range in size from 5 to 50 micron on a side. Four probe I-V measurements at 4.2 K show RnA products as low as 6 x 10 to the -9th sq cm and critical current densities up to 5.2 kA/sq cm. AC Josephson steps were observed with the application of 10-GHz radiation. The temperature dependence of Jc and the observation of the AC Josephson effect suggest that true supercurrents are present and that they do indeed represent the characteristics of the YBa2Cu3O(7-delta)/Au/Nb structure. The best results were obtained when the devices were annealed at about 450 C in O2 for 30 min after Au deposition.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 1335-133
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  • 22
    Publication Date: 2011-08-19
    Description: A novel waveguide power transmission measurement technique was developed to extract the complex conductivity of superconducting thin films at microwave frequencies. The microwave conductivity was taken of two laser ablated YBa2Cu3O(7-delta) thin films on LaAlO3 with transition temperatures of approximately 86.3 and 82 K, respectively, in the temperature range 25 to 300 K. From the conductivity values, the penetration depth was found to be approximately 0.54 and 0.43 micron, and the surface resistance (R sub s) to be approximately 24 and 36 micro-Ohms at 36 GHz and 76 K for the two films under consideration. The R sub s values were compared with those obtained from the change in the Q-factor of a 36 GHz Te sub 011-mode (OFHC) copper cavity by replacing one of its end walls with the superconducting sample. This technique allows noninvasive characterization of high transition superconducting thin films at microwave frequencies.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 1284-128
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  • 23
    Publication Date: 2011-08-19
    Description: Allowing for a field-dependent critical current density, the authors calculate the magnetic field that can be supported by hollow cylinders of varying wall thickness. An adiabatically stable field of 1.0 T can be shielded by or trapped in a cylinder with a wall thickness of 0.4 cm if the critical current density varies linearly with magnetic field and has a value of 104 A/sq cm at a field of 1.0 T. Such a current density appears to be within reach of present state-of-the-art melt-processed YBa2Cu3O7 (123) materials.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 1047
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  • 24
    Publication Date: 2011-08-19
    Description: A resonant-tunneling diode has oscillated at X-band frequencies in a microwave circuit consisting of a slot antenna coupled to a semiconfocal open resonator. Coupling between the open resonator and the slot oscillator improves the noise-to-carrier ratio by about 36 dB relative to that of the slot oscillator alone in the 100-200 kHz range. A circuit operating near 10 GHz has been designed as a scale model for millimeter- and submillimeter-wave applications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electronics Letters (ISSN 0013-5194); 27; 647-649
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  • 25
    Publication Date: 2011-08-19
    Description: A guide-antiguide modulator of GaAs-AlGaAs using the electric-field-induced waveguide concept was demonstrated. The device was formed with a central waveguide electrode sandwiched between two antiguide electrodes on the surface of a p-i-n multiple quantum well (MQW). Switching between lateral guiding and antiguiding was accomplished by reverse biasing either the central electrode or the adjacent electrodes to increase the index beneath these respective regions. The on-off ratio was measured to be 20:1 with a propagation loss of the on-state of about 5 dB/mm.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Photonics Technology Letters (ISSN 1041-1135); 3; 141-143
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  • 26
    Publication Date: 2011-08-19
    Description: A novel gate insulator consisting of silicon dioxide (SiO2) with a thin silicon (Si) interfacial layer has been investigated for high-power microwave indium phosphide (InP) metal-insulator-semiconductor field effect transistors (MISFETs). The role of the silicon interfacial layer on the chemical nature of the SiO2/Si/InP interface was studied by high-resolution X-ray photoelectron spectroscopy. The results indicated that the silicon interfacial layer reacted with the native oxide at the InP surface, thus producing silicon dioxide, while reducing the native oxide which has been shown to be responsible for the instabilities in InP MISFETs. While a 1.2-V hysteresis was present in the capacitance-voltage (C-V) curve of the MIS capacitors with silicon dioxide, less than 0.1 V hysteresis was observed in the C-V curve of the capacitors with the silicon interfacial layer incorporated in the insulator. InP MISFETs fabricated with the silicon dioxide in combination with the silicon interfacial layer exhibited excellent stability with drain current drift of less than 3 percent in 10,000 sec, as compared to 15-18 percent drift in 10,000 sec for devices without the silicon interfacial layer. High-power microwave InP MISFETs with Si/SiO2 gate insulators resulted in an output power density of 1.75 W/mm gate width at 9.7 GHz, with an associated power gain of 2.5 dB and 24 percent power added efficiency.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electrochemical Society, Journal (ISSN 0013-4651); 138; 1788-179
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  • 27
    Publication Date: 2011-08-19
    Description: A four-way crossover circuit using a cylindrical cavity with four rectangular input/output ports has been designed to feed a cross-slot antenna to achieve dual polarization. Because all the input and output circuits are waveguides, the network is especially useful for high power systems and millimeter wave applications. The crossover circuit exhibits a very low insertion loss and good isolation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electronics Letters (ISSN 0013-5194); 27; 997
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  • 28
    Publication Date: 2011-08-19
    Description: An analysis is carried out to determine the discontinuity susceptance of a circular or rectangular aperture in the transverse plane of a circular waveguide. Closed-form solutions based on the scattered amplitude calculation and aperture coupling theory are derived. Example solutions for a small circular aperture and a resonant rectangular aperture are given. The calculated results agree very well with the experiments. The results have many applications in the design of circular waveguide components and circular waveguide-backed aperture antennas.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Microwave Theory and Techniques (ISSN 0018-9480); 39; 718-723
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  • 29
    Publication Date: 2011-08-19
    Description: 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.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Electron Devices (ISSN 0018-9383); 38; 930-932
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  • 30
    Publication Date: 2011-08-19
    Description: Measured mutual coupling between two X-band electromagnetically coupled rectangular patch antennas is reported. Results are given for both the wideband and high gain regions as well as for E-plane and H-plane couplings.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electronics Letters (ISSN 0013-5194); 27; 532
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  • 31
    Publication Date: 2011-08-19
    Description: The performance of a microstrip hammerhead filter that has been fabricated on an electrically thin layer of semiinsulating GaAs backed by a fused quartz substrate was measured and compared to results of a three-dimensional finite-difference time-domain (FD-TD) program used to calculate the response of the filter both with and without the GaAs layer. The program, presented by Sheen et al. (1990), discretizes the entire structure and then simulates the propagation of a Gaussian pulse through the filter. The microstrip filter is intended for applications involving ultrathin lifted-off or etched-back GaAs containing both active devices and passive microstrip circuitry backed by a much thicker mechanically rigid low-loss, low-dielectric-constant substrate. The low-pass characteristics of the hammerhead filter with the intermediate GaAs layer are compared with those of the same filter on quartz alone. Both the measured and computed data show a significant shift in cutoff frequency (about 10 percent at the 3 dB points) for a GaAs layer that is 0.007 wavelengths thick at 4 GHz.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Microwave and Guided Wave Letters (ISSN 1051-8207); 1; 78-80
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  • 32
    Publication Date: 2011-08-19
    Description: Graphite intercalation compounds may provide an excellent material for the fabrication of electromagnetic railgun armatures. As a pulse of power is fed into the armature the intercalate could be excited into the plasma state around the edges of the armature, while the bulk of the current would be carried through the graphite block. Such an armature would have both diffuse plasma armatures and bulk conduction armatures. In addition, the highly anisotropic nature of these materials could enable the electrical and thermal conductivity to be tailored to meet the specific requirements of electromagnetic railgun armatures. Preliminary investigations have been performed in an attempt to determine the feasibility of using graphite intercalation compounds as railgun armatures. Issues of fabrication, resistivity, stability, and electrical current spreading have been addressed for the case of highly oriented pyrolytic graphite.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 289-293
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  • 33
    Publication Date: 2011-08-19
    Description: The observation of photon-assisted resonant tunneling in a multiple quantum well structure composed of doped quantum wells separated by variably space superlattice energy filters is reported. Electrons confined in the quantum wells are excited to the second quantized state by intersubband absorption of incident infrared radiation and are subsequently emitted through the filters under appropriate bias conditions. This is manifested by a distinct peak, with an associated negative differential photoconductance, in the photocurrent versus bias voltage characteristic at low temperatures.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 58; 1297
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  • 34
    Publication Date: 2011-08-19
    Description: An experimental and numerical study is conducted of the operation of a major line in a vertical Bloch-line memory that employs a partial garnet-grooving architecture and contains (1) a bubble generator; (2) a bubble-propagation track; (3) a bubble-expander for detection; and (4) a bubble annihilator. The bubble expander is a modification of the propagation track; the meandering conductor and groove width were gradually increased to stretch the bubble into a stripe. The numerical model employed encompasses the garnet-grooving effect. Agreement is obtained between exparimental and simulation results.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 69; 5754-575
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  • 35
    Publication Date: 2011-08-19
    Description: An approach is described for using the linear sweep voltammetry (LSV) technique to study the kinetics of flooded porous electrodes by assuming a porous electrode as a collection of identical noninterconnected cylindrical pores that are filled with electrolyte. This assumption makes possible to study the behavior of this ideal electrode as that of a single pore. Alternatively, for an electrode of a given pore-size distribution, it is possible to predict the performance of different pore sizes and then combine the performance values.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electrochemical Society, Journal (ISSN 0013-4651); 138; 258C-264
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  • 36
    facet.materialart.
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    In:  Other Sources
    Publication Date: 2011-08-19
    Description: An outline is presented of the coilgun concept, excitation, switching, brush commutation, power supply, and performance. It is shown that a traveling-wave synchronous coilgun permits independent adjustment of the magnetic field and armature current for high velocity at low armature mass fraction. Magnetic field energy is transferred from the rear of the wave to the front without passing through the power supply. Elaborate switching is required.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 647-649
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  • 37
    facet.materialart.
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    In:  Other Sources
    Publication Date: 2011-08-19
    Description: The consequence of frequency domain multiple access channelization in a satellite communications system is that the ground- and space-based components often are required to operate in a linear region to prevent the generation of distortion signals. Components of a time division multiple access (TDMA) satellite system, such as a traveling-wave tube (TWT), can operate in the highest output power state because the channelization technique is relatively insensitive to the distortions resulting from saturated operation. A 30 GHz TWT was tested to determine the suitability of such a device in a TDMA system. Testing was focused on the ability of the TWT's output signal to rise up to full power at the leading edge of TDMA bursts, simulated by a pulse train. A peak power meter was used to display and measure the pulsed signal waveform. Measurements on the TWT output pulse rise time indicate that the TWT lengthened the rise time by 10 to 20 ns. Imposing modulator turn on timing that precedes the data burst by the TWT rise time is a logical approach to coordination of the two subsystem specification.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Microwave Journal (ISSN 0192-6225); 34; 113
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  • 38
    Publication Date: 2011-08-19
    Description: Plasma-deposited germanium nitride was investigated for the first time as a possible gate insulator for InP compound semiconductor metal-insulator-semiconductor FET (MISFET) technology. The germanium nitride films were successfully deposited in a capacitively coupled parallel plate reactor at 13.56 MHz operation using GeH4/N2/NH3 and GeH4/N2 mixtures as reactant gases. The former process produced better quality films with enhanced uniformity, increased deposition rates, and increased resistivity. The breakdown field strength of the films was greater than 10 to the 6th V/cm. Auger electron spectroscopy did not indicate significant chemical composition differences between the two processes. For MISFETs with 2-micron channel lengths fabricated on InP, the device transconductance and threshold voltage for the GeH4/N2/NH3 process were 17 mS/mm and -3.6 V, respectively. The drain-source breakdown voltages were greater than 10 V.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 69; 3616-362
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  • 39
    Publication Date: 2011-08-19
    Description: In an optically fed phased array antenna system, the microwave carrier signal is transmitted via a modulated lightwave to each active T/R (transmit/receive) module, where it must be converted back to the microwave domain. Currently, efficient optical-to-microwave conversion is extremely difficult, as the detected microwave signal is weak and noisy. A novel circuit, containing a high-gain/low-noise microwave injection-locked oscillator, has been developed to improve the interface between the optical and microwave components. The circuit utilizes two FETs and a dielectric resonator, which serves as a frequency-dependent feedback element. The circuit, designed to operate at about 8 GHz, provides significant amplitude and phase noise suppression. In addition, the circuit realization is compatible with MMIC technology.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Microwave Theory and Techniques (ISSN 0018-9480); 39; 201-208
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  • 40
    Publication Date: 2011-08-19
    Description: A theoretical comparison of various low and high order multipliers for 200 GHz and 1 THz has been carried out. Novel diodes including single barrier varactors, barrier-intrinsic-n(+)diodes and high electron mobility varactors are shown to have excellent theoretical performance, comparable or better than the conventional Schottky varactors for single and double diode frequency multipliers at millimeter and submillimeter wavelengths, whereas quantum well diodes, since they suffer from high resistive losses, are shown to be less attractive. In comparison to the conventional Schottky varactor, these new diodes have some potential advantages in their characteristics such as a stronger nonlinearity or a special symmetry. For future optimization some general comments on these advantages as well as other factors affecting multiplication are given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: International Journal of Infrared and Millimeter Waves (ISSN 0195-9271); 12; 1111-113
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  • 41
    Publication Date: 2011-08-19
    Description: The paper reports on a detailed experimental investigation of lateral tunneling between electrodes of a two-dimensional electron gas separated by the voltage-controlled barrier of a nanometer Schottky gate. The experimental data are modeled using the WKB method to calculate the tunneling probability of electrons through a barrier whose shape is determined from a solution of the two-dimensional Poisson equation. This model is in excellent agreement with the experimental data over a two order of magnitude range of current.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 59; 213-215
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  • 42
    Publication Date: 2011-08-19
    Description: An analysis of the expected space radiation effects on the single event upset (SEU) properties of CMOS/bulk memories onboard the Combined Release and Radiation Effects Satellite (CRRES) is presented. Dose-imprint data from ground test irradiations of identical devices are applied to the predictions of cosmic-ray-induced space upset rates in the memories onboard the spacecraft. The calculations take into account the effect of total dose on the SEU sensitivity of the devices as the dose accumulates in orbit. Estimates of error rates, which involved an arbitrary selection of a single pair of threshold linear energy transfer (LET) and asymptotic cross-section values, were compared to the results of an integration over the cross-section curves versus LET. The integration gave lower upset rates than the use of the selected values of the SEU parameters. Since the integration approach is more accurate and eliminates the need for an arbitrary definition of threshold LET and asymptotic cross section, it is recommended for all error rate predictions where experimental sigma-versus-LET curves are available.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); 38; 913-922
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  • 43
    Publication Date: 2011-08-19
    Description: The longest-wavelength quantum well infrared photodetector (QWIP) ever measured is demonstrated. This QWIP has a cutoff wavelength of 14.9 microns. The results show that even longer wavelength detectors should be possible.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Electronics Letters (ISSN 0013-5194); 27; 1512
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  • 44
    Publication Date: 2011-08-19
    Description: Depletion-mode InGaAs microwave power MISFETs with 1-micron gate lengths and up to 1-mm gate widths have been fabricated using an ion-implantation process. The devices employed a plasma-deposited silicon/silicon dioxide gate insulator. The dc I-V characteristics and RF power performance at 9.7 GHz are presented. The output power, power-added efficiency, and power gain as a function of input power are reported. An output power of 1.07 W with a corresponding power gain and power-added efficiency of 4.3 dB and 38 percent, respectively, was obtained. The large-gate-width devices provided over twice the previously reported output power for InGaAs MISFETs at X-band. In addition, output power stability within 1.2 percent over 24 h of continuous operation was achieved. In addition, a drain current drift of 4 percent over 10,000 sec was obtained.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Microwave Theory and Techniques (ISSN 0018-9480); 39; 1069-107
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  • 45
    Publication Date: 2011-08-19
    Description: The controllable, reproducible fabrication of nonhysteretic Josephson devices with excess-current weak-link characteristics at temperatures up to 80 K have been demonstrated. The devices are patterned from in situ deposited a-axis oriented YBa2Cu3O(7-y) - PrBa2Cu3O(7-y) - YBa2Cu3O(7-y) trilayers grown on SrTiO3(001) substrates. Control of the critical current density and resistance is achieved by varying the thickness of the PrBa2Cu3O(7-z) barrier layer. Critical current densities in excess of 10,000 A/sq cm have been reproducibly measured; good uniformity across the wafer is obtained with device parameters scaling with device area. Strong constant-voltage current steps are observed under 11.2 GHz microwave radiation at temperatures up to and above 80 K.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 59; 742-744
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  • 46
    Publication Date: 2011-08-19
    Description: Advances in high-frequency resonant-tunneling-diode (RTD) oscillators are described. Oscillations up to a frequency of 420 GHz have been achieved in the GaAs/AlAs system. Recent results obtained with In0.53Ga0.47As/AlAs and InAs/AlSb RTDs show a greatly increased power density and indicate the potential for fundamental oscillations up to about 1 THz. These results are consistent with a lumped-element equivalent circuit model of the RTD. The model shows that the maximum oscillation frequency of the GaAs/AlAs RTDs is limited primarily by series resistance, and that the power density is limited by low peak-to-valley current ratio.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Microwave and Optical Technology Letters (ISSN 0895-2477); 4; 19-23
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  • 47
    Publication Date: 2011-08-19
    Description: Oscillations have been obtained at frequencies from 100 to 712 GHz in InAs/AlSb double-barrier resonant-tunneling diodes at room temperature. The measured power density at 360 GHz was 90 W/sq cm, which is 50 times that generated by GaAs/AlAs diodes at essentially the same frequency. The oscillation at 712 GHz represents the highest frequency reported to date from a solid-state electronic oscillator at room temperature.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 58; 2291-229
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  • 48
    Publication Date: 2011-08-19
    Description: A refinement in the way hard-axis demagnetizing effects are treated in multilayer M-R memory elements brings experimental and calculated results into agreement for both the forward and reverse switching thresholds. In the improved model, the nonuniform rotation of the magnetization in the elements because of edge pinning is taken into account. The demagnetizing fields are treated as corrections to the hard-axis word field rather than an addition to the anisotropy constant.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 69; 5763
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  • 49
    Publication Date: 2011-08-19
    Description: New multilayer permalloy materials with thin separation layers that have significantly increased M-R coefficients at room temperature have the potential for substantially increasing both the speed and density of M-R memories. An analysis in the following discussion shows that the bit density at a given performance level is related to the product of M-R response and sheet resistivity when operating at the current-density limit. With a doubling of both sheet resistivity and M-R response over existing materials, the bit area can be reduced by about a factor of 4. Alternatively, if the bit area is kept the same, signal output is increased by a factor of 4 and circuit time constants can be reduced by a factor of 16.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 69; 5760-576
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  • 50
    facet.materialart.
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    In:  Other Sources
    Publication Date: 2011-08-19
    Description: Properties of NbN films and NbN/MgO/NbN tunnel junctions are discussed. NbN junctions are being developed for use in high-frequency, SIS quasiparticle mixers. To properly design mixer circuits, junction and film properties need to be characterized. The specific capacitance of NbN/MgO/NbN junctions has been measured as a function of the product of the normal-state resistance and the junction area (RnA), and it is found to vary by more than a factor of two (35-85 fF/sq microns) over the range of RnA measured (1000-50 ohm sq microns). This variation is important because the specific capacitance determines the RC speed of the tunnel junction at a given RnA value. The magnetic penetration depth of NbN films deposited under different conditions is also measured. The magnetic penetration depth affects the design of microstrip line used in RF tuning circuits. Control of the magnetic penetration depth is necessary to fabricate reproducible tuning circuits. Additionally, the critical current uniformity for arrays of 100 junctions has been measured. Junction uniformity will affect the design of focal-plane arrays of SIS mixers. Finally, the relevance of these measurements to the design of Josephson electronics is discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 3196-319
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  • 51
    Publication Date: 2011-08-19
    Description: The development of submicron area mixer elements for operation in the submillimeter wave range is discussed. High-current-density NbN/MgO/NbN tunnel junctions with areas down to 0.1 sq microns have been fabricated in both planar and edge geometries. The planar junctions were fabricated from in situ deposited trilayers using electron-beam lithography to pattern submicron area mesas. Modifications of fabrication techniques used in larger-area NbN tunnel junctions are required and are discussed. The NbN/MgO/NbN edge junction process using sapphire substrates has been transferred to technologically important quartz substrates using MgO buffer layers to minimize substrate interactions. The two junction geometries are compared and contrasted in the context of submillimeter wave mixer applications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 3192-319
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  • 52
    Publication Date: 2011-08-19
    Description: Microstrip transmission lines in the form of ring resonators were fabricated from a number of in-situ grown laser ablated films and post-annealed co-sputtered YBa2Cu3O(7-x) films. The properties of these resonators were measured at 35 GHz and the observed performance is examined in light of the critical temperature (Tc) and film thickness, and also the film morphology, which is different for the two deposition techniques. It is found that Tc is a major indicator of the film performance for each growth type, with film thickness becoming important as it decreases towards 1000 A. It is also found that the films with a mixed grain orientation (both a-axis and c-axis oriented grains) have poorer microwave properties as compared with the primarily c-axis oriented material. This is probably due to the significant number of grain boundaries between the different crystallites, which may act as superconducting weak links and contribute to the surface resistance.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 2940-294
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  • 53
    Publication Date: 2011-08-19
    Description: An experiment dealing with high-temperature superconducting devices and components in space is discussed. A variety of devices (primarily passive microwave and millimeter-wave components) has been procured and will be integrated with a cryogenic refrigerating and data acquisition system to form the space package, which will be launched in late 1992. This space experiment is expected to demonstrate that this technology is sufficiently robust to survive the space environment and that the technology has the potential to improve the operation of space systems significantly. The devices for the initial launch have been evaluated electrically, thermally, and mechanically, and will be integrated into the final space package early in 1991. The performance of the devices is summarized, and some potential applications of this technology in space systems are outlined.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 2533-253
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  • 54
    Publication Date: 2011-08-19
    Description: Small area (less than 1 sq micron), high-current-density NbN/MgO/NbN tunnel junctions with I-V characteristics suitable for high-frequency mixers have been fabricated. Mesa-geometry junctions with an area of about 1 sq micron and critical current density of 5-10 kA/sq cm are integrated with superconducting microstrip lines designed to resonate out the junction capacitance. A study was made of the mixer gain and noise performance near 205 GHz as a function of the inductance provided by the microstrip line. This has confirmed, at a high millimeter-wave frequency, values of junction capacitance of 85 fF/sq micron and recently measured values of a magnetic penetration depth of 380 nm. Mixer noise temperatures as low as 134 K at 1.5 K have been obtained for properly tuned junctions. A significant improvement in mixer performance on cooling from 4.2 K to 1.5 K was observed. Edge-geometry junctions with an area of 0.3 sq microns and critical current density of 18-25 kA/sq cm have also been fabricated. These junctions give a mixer noise temperature of 145 K at 4.2 K without the use of integrated tuning elements. These are the best results ever achieved for NbN-based SIS mixers.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Magnetics (ISSN 0018-9464); 27; 2650-265
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  • 55
    Publication Date: 2011-08-19
    Description: Long, partial rectangular grooves have been made to reside below the stripe-confinement groove on a garnet surface, in order to stabilize minor loop stripes in a vertical Bloch-line memory. The test chip contained, in addition to either 10 or 20 minor-loop grooves, 10 read/write gate grooves and a major line groove; both 10 and 20 micron groove periods were tested. As the bias field was gradually decreased, bubbles began to stripe out. These stripes were stable at bias fields in the 70-80 Oe range. When stripes escaped from the groove, the even occurred from the end which does not face a read/write gate groove.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 69; 5751-575
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  • 56
    Publication Date: 2011-08-19
    Description: The results of a 600-GHz mixer performance analysis using an improved model for computing the Schottky diode capacitance-voltage (C-V) relationship are presented. The computed C-V data for a realistic submillimeter-waver mixer diode are given as a function of physical temperature and compared to the standard analytic expression based on a solution of Poisson's equation. Both C-V relationships are used to predict the performance of an ideally terminated 600 GHz mixer operating at 300, 140, 80, and 30 K. It is shown that the drift-diffusion model more accurately describes the mixer performance when the physical temperature is reduced below roughly 100 K.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Microwave and Guided Wave Letters (ISSN 1051-8207); 1; 129-131
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  • 57
    facet.materialart.
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    In:  Other Sources
    Publication Date: 2011-08-24
    Description: This paper reports on free-standing ultrafine fibers formed using the gas-evaporation method in the presence of electric fields. Materials up to 10 cm in length have been prepared in this way. Electrical measurements on Pd fibers 3 mm in length and about 200-300 A in diameter are given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 59; 3393-339
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  • 58
    Publication Date: 2011-08-24
    Description: Success has been achieved in extending the spectral wavelength of GaAs/Al(x)Ga(1-x)As quantum-well infrared photodetectors to significantly longer wavelengths of 11-15 micron. High responsivity of 0.5 A/W, high quantum efficiency of 12 percent, and high detectivity as well as an excellent noise equivalent temperature difference of 4 mK have been achieved at T = 50 K. High performance of 19 mK has also been achieved at an even higher temperature of 60 K.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Journal of Applied Physics (ISSN 0021-8979); 70; 5101-510
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  • 59
    Publication Date: 2011-08-24
    Description: The theoretical analysis presented indicates that Auger recombination can reduce charge collection from very dense ion tracks in silicon devices. It is of marginal importance for tracks produced by 270-MeV krypton, and therefore it is of major importance for ions exhibiting a significantly larger loss. The analysis shows that recombination loss is profoundly affected by track diffusion. As the track diffuses, the density and recombination rate decrease so fast that the linear density (number of electron-hole pairs per unit length) approaches a nonzero limiting value as t approaches infinity. Furthermore, the linear density is very nearly equal to this limiting value in a few picoseconds or less. When Auger recombination accompanies charge transport processes that have much longer time scales, it can be simulated by assigning a reduced linear energy transfer to the ion.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); 38; 999-1004
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  • 60
    facet.materialart.
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    In:  CASI
    Publication Date: 2013-08-31
    Description: A new basic VLSI circuit element is presented that can be used to realize pulse mode asynchronous sequential circuits. A synthesis procedure is developed along with an unconventional state assignment procedure. Level input asynchronous sequential circuits can be realized by converting a regular flow table into a differential mode flow table, thereby allowing the new synthesis technique to be general. The new circuits tolerate 1-1 crossovers. This circuit also provides a means for state sequence detection and real time fault detection.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 11 p
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  • 61
    Publication Date: 2013-08-31
    Description: It has previously been shown that the Reed-Solomon (RS) codes can correct errors beyond the Singleton and Rieger Bounds with an arbitrarily small probability of a miscorrect. That is, an (n,k) RS code can correct more than (n-k)/2 errors. An implementation of such an RS decoder is presented in this paper. An existing RS decoder, the AHA4010, is utilized in this work. This decoder is especially useful for errors which are patterned with a long burst plus some random errors.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 9 p
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  • 62
    Publication Date: 2013-08-31
    Description: A single phase dynamic CMOS NOR-NOR programmable logic array (PLA) using triggered decoders and charge sharing techniques for high speed and low power is presented. By using the triggered decoder technique, the ground switches are eliminated, thereby, making this new design much faster and lower power dissipation than conventional PLA's. By using the charge-sharing technique in a dynamic CMOS NOR structure, a cascading AND gate can be implemented. The proposed PLA's are presented with a delay-time of 15.95 and 18.05 nsec, respectively, which compare with a conventional single phase PLA with 35.5 nsec delay-time. For a typical example of PLA like the Signetics 82S100 with 16 inputs, 48 input minterms (m) and 8 output minterms (n), the 2-SOP PLA using the triggered 2-bit decoder is 2.23 times faster and has 2.1 times less power dissipation than the conventional PLA. These results are simulated using maximum drain current of 600 micro-A, gate length of 2.0 micron, V sub DD of 5 V, the capacitance of an input miniterm of 1600 fF, and the capacitance of an output minterm of 1500 fF.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Idaho Univ., The 1991 3rd NASA Symposium on VLSI Design; 12 p
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  • 63
    Publication Date: 2013-08-31
    Description: The Air Force Manufacturing Technology program is involved with the improvement of radar transmit/receive modules for use in active phased array radars for advanced fighter aircraft. Improvements in all areas of manufacture and test of these modules resulting in order of magnitude improvements in the cost of and the rate of production are addressed, as well as the ongoing transfer of this technology to the Navy.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 1; p 243-246
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  • 64
    Publication Date: 2013-08-31
    Description: Since 1985, the Naval Ocean Systems Center has been identifying and developing needed technology for flexible manufacturing of hybrid microelectronic assemblies. Specific projects have been accomplished through contracts with manufacturing companies, equipment suppliers, and joint efforts with other government agencies. The resulting technology has been shared through semi-annual meetings with government, industry, and academic representatives who form an ad hoc advisory panel. More than 70 major technical capabilities have been identified for which new development is needed. Several of these developments have been completed and are being shared with industry.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 1; p 235-242
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  • 65
    Publication Date: 2013-08-31
    Description: A new noncontacting waveguide backshort was developed for millimeter and submillimeter wave frequencies. It employs a metallic bar with rectangular or circular holes. The size and spacing of the holes are adjusted to provide a periodic variation of the guide impedance on the correct length scale to give a large reflection of RF frequency power. This design is mechanically rugged and can be easily fabricated for millimeter wave frequencies above 300 GHz where conventional backshorts are difficult to fabricate. Model experiments were performed at 4 to 6 GHz to optimize the design. Values of reflected power greater than 95 percent over a 30 percent bandwidth were achieved. The design was scaled to WR-10 band (75 to 110 GHz) with comparably good results.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 1; p 161-168
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  • 66
    Publication Date: 2013-08-31
    Description: Transistor design for extremely high frequency applications requires consideration of the interaction between the device and the circuit to which it is connected. Traditional analytical transistor models are to approximate at some of these frequencies and may not account for variations of dopants and semiconductor materials (especially some of the newer materials) within the device. Physically based models of device performance are required. These are based on coupled systems of partial differential equations and typically require 20 minutes of Cray computer time for a single AC operating point. A technique is presented to extract parameters from a few partial differential equation solutions for the device to create a nonlinear equivalent circuit model which runs in approximately 1 second of personal computer time. This nonlinear equivalent circuit model accurately replicates the contact current properties of the device as computed by the partial differential solver on which it is based. Using the nonlinear equivalent circuit model of the device, optimization of systems design can be performed based on device/circuit interactions.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Pennsylvania State Univ., Third International Conference on Inverse Design Concepts and Optimization in Engineering Sciences (ICIDES-3); p 573-591
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  • 67
    facet.materialart.
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    In:  CASI
    Publication Date: 2013-08-31
    Description: We are interested in tracing the convective profiles of vertical Bridgman growth in two configurations, the pure Rayleigh convective mode and the combined Rayleigh-Marangoni mode. In order to do so, we conducted a numerical investigation that involved a finite volume calculation. The governing equations were integrated about a cell volume, using the Gauss Theorem and the volume variables like temperature and velocity were related to the surface variables. In order to solve for the pressure field, we employed the continuity equation and the residuals resulted in a Poisson equation. Results and comments for the Rayleigh and Marangoni problems in a vertical cylinder or Bridgman configuration are given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Old Dominion Univ., NASA/American Society for Engineering Ed; Old Dominion Univ.,
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  • 68
    Publication Date: 2013-08-31
    Description: A test technique was developed to assess various grounding system concepts used for mobile facilities. The test technique involves applying a high current pulse to the grounding system with the proper waveshape and magnitude to simulate a lightning return stroke. Of concern were the step voltages present along the ground near the point of lightning strike. Step voltage is equated to how fast the current pulse is dissipated by the grounding system. The applied current pulse was produced by a high current capacitor bank with a total energy content of 80 kilojoules. A series of pulse tests were performed on two types of mobile facility grounding systems. One system consisted of an array of four 10 foot copper clad steel ground rods connected by 1/0 gauge wire. The other system was an array of 10 inch long tapered ground rods, strung on stainless steel cable. The focus here is on the pulse test technique used and its relevance to actual lightning strike conditions.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 10 p
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  • 69
    Publication Date: 2013-08-31
    Description: Voltages induced by overhead cloud lightning on a 448 m open circuited power distribution line and the corresponding north-south component of the lightning magnetic field were simultaneously measured at the NASA Kennedy Space Center during the summer of 1986. The incident electric field was calculated from the measured magnetic field. The electric field was then used as an input to the computer program, EMPLIN, that calculated the voltages at the two ends of the power line. EMPLIN models the frequency domain field/power coupling theory found, for example, in Ianoz et al. The direction of the source, which is also one of the inputs to EMPLIN, was crudely determined from a three station time delay technique. The authors found reasonably good agreement between calculated and measured waveforms.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 9 p
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  • 70
    Publication Date: 2013-08-31
    Description: The charging of a target by riming in the wind was studied in the temperature range of (-10, -18 C). For each temperature, charge transfers of both signs are observed and, according to the environmental conditions, one of them prevails. The charge is more positive as the liquid water concentration is increased at any particular temperature. It is found that even at the low impact velocities used (5 m/s) there is abundant evidence of fragmentation following the collision.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 15 p
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  • 71
    Publication Date: 2013-08-31
    Description: Test data and analytic evaluations are presented to show that relatively poor 100 KHz shielding of 12 Db can effectively provide an electromagnetic pulse transient reduction of 100 Db. More importantly, several techniques are shown for lightning surge attenuation as an alternative to crowbar, spark gap, or power zener type clipping which simply reflects the surge. A time delay test method is shown which allows CW testing, along with a convolution program to define transient shielding effectivity where the Fourier phase characteristics of the transient are known or can be broadly estimated.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 5 p
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  • 72
    Publication Date: 2013-08-31
    Description: A redesign effort was undertaken starting in the fall of 1988 to replace the Models 1019A and 1019B fieldmeter probes resulting in greatly improved performance. Extensive testing was conducted to confirm performance of the new design and to evaluate outdoor atmospheric applicability. The following subjects are discussed: theory of operation, design improvements, performance, proper use, and applications of the new intrinsically safe design.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 13 p
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  • 73
    Publication Date: 2013-08-31
    Description: The principal sources of errors during airborne measurements of the ambient electric field and charge are addressed. Results of their analysis are presented for critical survey. It is demonstrated that the volume electric charge has to be accounted for during such measurements, that charge being generated at the airframe and wing surface by droplets of clouds and precipitation colliding with the aircraft. The local effect of that space charge depends on the flight regime (air speed, altitude, particle size, and cloud elevation). Such a dependence is displayed in the relation between the collector conductivity of the aircraft discharging circuit - on one hand, and the sum of all the residual conductivities contributing to aircraft discharge - on the other. Arguments are given in favor of variability in the aircraft electric capacitance. Techniques are suggested for measuring from factors to describe the aircraft charge.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 11 p
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  • 74
    Publication Date: 2013-08-31
    Description: The new Section 23 is introduced which has only very recently been fully approved by the RTCA for incorporation into the first revision of DO160C/ED14C. Full threat lightning direct effects testing of equipment is entirely new to DO160, the only existing lightning testing is transient testing for LRU's (Line Replaceable Units) by pin or cable bundle injection methods, for equipment entirely contained within the airframe and assumed to be unaffected by direct effects. This testing required transients of very low amplitude compared with lightning itself, whereas the tests now to be described involve full threat lightning testing, that is using the previously established severe parameters of lightning appropriate to the Zone, such as 200 kA for Zone 1A as in AC20-136. Direct effects (i.e., damage) testing involves normally the lightning current arc attaching to the object under test (or very near to it) so submitting it to full potential for the electric, mechanical, thermal and shock damage which is caused by high current arcing. Since equipment for any part of the airframe require qualification, tests to demonstrate safety of equipment in fuel vapor regions of the airframe are also included.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 9 p
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  • 75
    Publication Date: 2013-08-31
    Description: Various techniques were studied to predict the transient current induced into aircraft wiring bundles as a result of an aircraft lightning strike. A series of aircraft measurements were carried out together with a theoretical analysis using computer modeling. These tests were applied to various aircraft and also to specially constructed cylinders installed within coaxial return conductor systems. Low level swept frequency CW (carrier waves), low level transient and high level transient injection tests were applied to the aircraft and cylinders. Measurements were made to determine the transfer function between the aircraft drive current and the resulting skin currents and currents induced on the internal wiring. The full threat lightning induced transient currents were extrapolated from the low level data using Fourier transform techniques. The aircraft and cylinders used were constructed from both metallic and CFC (carbon fiber composite) materials. The results show the pulse stretching phenomenon which occurs for CFC materials due to the diffusion of the lightning current through carbon fiber materials. Transmission Line Matrix modeling techniques were used to compare theoretical and measured currents.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 2; 10 p
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  • 76
    Publication Date: 2013-08-31
    Description: Considerable controversy has arisen during the recent discussions over a new version of the RTCA DO160C/ED 14C Section 22 document at the European Committee for Aviation Electronics. Section 22 is concerned with lightning waveform tests to equipment. Investigations of some of these controversies with circuit analysis and measurements indicate the impedance characteristics required of the transient generators and the possibility of testing to a voltage limit even for current waveforms.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 1; 10 p
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  • 77
    Publication Date: 2013-08-31
    Description: Extensive measurements of induced voltages and currents were made using a CFC (carbon fiber composites) horizontal stabilizer from the A320 as a test bed. The work was done to investigate the efficacy of various protection schemes to reduce the magnitudes of the induced voltages and validate a computer program INDCAL. Results indicate that a good understanding of the various induced voltage mechanisms including the long wave effect due to current redistribution was obtained.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 1; 10 p
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  • 78
    Publication Date: 2013-08-31
    Description: When video replaces film the digitized video data accumulates very rapidly, leading to a difficult and costly data storage problem. One solution exists for cases when the video images represent continuously repetitive 'static scenes' containing negligible activity, occasionally interrupted by short events of interest. Minutes or hours of redundant video frames can be ignored, and not stored, until activity begins. A new, highly parallel digital state machine generates a digital trigger signal at the onset of a video event. High capacity random access memory storage coupled with newly available fuzzy logic devices permits the monitoring of a video image stream for long term or short term changes caused by spatial translation, dilation, appearance, disappearance, or color change in a video object. Pretrigger and post-trigger storage techniques are then adaptable for archiving the digital stream from only the significant video images.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 1; p 254-260
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  • 79
    Publication Date: 2013-08-31
    Description: Two analog very large scale integration (VLSI) vector matrix multiplier integrated circuit chips were designed, fabricated, and partially tested. They can perform both vector-matrix and matrix-matrix multiplication operations at high speeds. The 32 by 32 vector-matrix multiplier chip and the 128 by 64 vector-matrix multiplier chip were designed to perform 300 million and 3 billion multiplications per second, respectively. An additional circuit that has been developed is a continuous-time adaptive learning circuit. The performance achieved thus far for this circuit is an adaptivity of 28 dB at 300 KHz and 11 dB at 15 MHz. This circuit has demonstrated greater than two orders of magnitude higher frequency of operation than any previous adaptive learning circuit.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 1; p 147-155
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  • 80
    Publication Date: 2013-08-31
    Description: A proof of concept Monolithic Microwave Integrated Circuit (MMIC) Water Vapor Radiometer (WVR) is under development at the Jet Propulsion Laboratory (JPL). WVR's are used to remotely sense water vapor and cloud liquid water in the atmosphere and are valuable for meteorological applications as well as for determination of signal path delays due to water vapor in the atmosphere. The high cost and large size of existing WVR instruments motivate the development of miniature MMIC WVR's, which have great potential for low cost mass production. The miniaturization of WVR components allows large scale deployment of WVR's for Earth environment and meteorological applications. Small WVR's can also result in improved thermal stability, resulting in improved calibration stability. Described here is the design and fabrication of a 31.4 GHz MMIC radiometer as one channel of a thermally stable WVR as a means of assessing MMIC technology feasibility.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 1; p 156-160
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  • 81
    Publication Date: 2013-08-31
    Description: 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.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Cincinnati Univ., OH, MMIC Integration Technology Investigation; p 44-69
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  • 82
    Publication Date: 2013-08-31
    Description: Monolithic microwave integrated circuits (MMIC), which incorporate all the elements of a microwave circuit on a single semiconductor substrate, offer the potential for drastic reductions in circuit weight and volume and increased reliability, all of which make many new concepts in electronic circuitry for space applications feasible, including phased array antennas. NASA has undertaken an extensive program aimed at development of MMICs for space applications. The first such circuits targeted for development were an extension of work in hybrid (discrete component) technology in support of the Advanced Communication Technology Satellite (ACTS). It focused on power amplifiers, receivers, and switches at ACTS frequencies. More recent work, however, focused on frequencies appropriate for other NASA programs and emphasizes advanced materials in an effort to enhance efficiency, power handling capability, and frequency of operation or noise figure to meet the requirements of space systems.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2000, Volume 2; p 242-248
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  • 83
    Publication Date: 2013-08-31
    Description: The union of Auburn University's Center for Space Power and Advanced Electronics and the Westinghouse Science and Technology Center to form a Center for the Commercial Development of Space (CCDS) is discussed. An area of focus for the CCDS will be the development of silicon carbide electronics technology, in terms of semiconductors and crystal growth. The discussion is presented in viewgraph form.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Proceedings of the Second Annual Symposium on Industrial Involvement and Successes in Commercial Space; 21 p
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  • 84
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2013-08-31
    Description: Johnson Controls is a 106 year old company employing 42,000 people worldwide with $4.7 billion annual sales. Though we are new to the aerospace industry we are a world leader in automobile battery manufacturing, automotive seating, plastic bottling, and facilities environment controls. The battery division produces over 24,000,000 batteries annually under private label for the new car manufacturers and the replacement market. We are entering the aerospace market with the nickel hydrogen battery with the help of NASA's Center for Space Power at Texas A&M. Unlike traditional nickel hydrogen battery manufacturers, we are reaching beyond the space applications to the higher volume markets of aircraft starting and utility load leveling. Though space applications alone will not provide sufficient volume to support the economies of scale and opportunities for statistical process control, these additional terrestrial applications will. For example, nickel hydrogen batteries do not have the environmental problems of nickel cadmium or lead acid and may someday start your car or power your electric vehicle. However you envision the future, keep in mind that no manufacturer moves into a large volume market without fine tuning their process. The Center for Space Power at Texas A&M is providing indepth technical analysis of all of the materials and fabricated parts of our battery as well as thermal and mechanical design computer modeling. Several examples of what we are doing with nickel hydrogen chemistry to lead to these production efficiencies are presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Proceedings of the Second Annual Symposium on Industrial Involvement and Successes in Commercial Space; 5 p
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  • 85
    Publication Date: 2013-08-31
    Description: Planar RF circuits are used in a wide range of applications from 1 GHz to 300 GHz, including radar, communications, commercial RF test instruments, and remote sensing radiometers. These circuits, however, provide only fixed tuning elements. This lack of adjustability puts severe demands on circuit design procedures and materials parameters. We have developed a novel tuning element which can be incorporated into the design of a planar circuit in order to allow active, post-fabrication tuning by varying the electrical length of a coplanar strip transmission line. It consists of a series of thin plates which can slide in unison along the transmission line, and the size and spacing of the plates are designed to provide a large reflection of RF power over a useful frequency bandwidth. Tests of this structure at 1 GHz to 3 Ghz showed that it produced a reflection coefficient greater than 0.90 over a 20 percent bandwidth. A 2 GHz circuit incorporating this tuning element was also tested to demonstrate practical tuning ranges. This structure can be fabricated for frequencies as high as 1000 GHz using existing micromachining techniques. Many commercial applications can benefit from this micromechanical RF tuning element, as it will aid in extending microwave integrated circuit technology into the high millimeter wave and submillimeter wave bands by easing constraints on circuit technology.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 2; p 239-245
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  • 86
    Publication Date: 2013-08-31
    Description: Discussed here is the successful fabrication of a five-pole interdigital stripline filter made of the 93 K superconductor (Y1Ba2Cu3O sub y) coated on a silver substrate, with center frequency of 8.5 GHz and an extremely high rejection ratio of 80 dB. The lowest injection loss measured was 0.1 dB at 12 K, with a return loss of better than 16 dB, representing a significant improvement over a similar copper filter, and is comparable to low critical temperature filters. The insertion loss appears to be limited by extrinsic factors, such as tuning mismatch and joint losses, and not by superconducting material losses.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA, Washington, Technology 2001: The Second National Technology Transfer Conference and Exposition, Volume 2; p 232-238
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  • 87
    Publication Date: 2013-08-31
    Description: Greater attention is being focused on the protection of data I/O ports since both experience and lab tests have shown that components at these locations are extremely vulnerable to electrical overstress (EOS) in the form of transient voltages. Lightning and electrostatic discharge (ESD) are the major contributors to these failures; however, these losses can be prevented. Hardening against transient voltages at both the board level and system level has a proven record of improving reliability by orders of magnitude. The EOS threats, typical failure modes, and transient voltage mitigation techniques are reviewed. Case histories are also reviewed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Kennedy Space Center, The 1991 International Aerospace and Ground Conference on Lightning and Static Electricity, Volume 1; 8 p
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  • 88
    Publication Date: 2013-08-31
    Description: 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.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: MMIC Integration Technology Investigation; p 1-42
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  • 89
    Publication Date: 2013-08-31
    Description: Charge-coupled devices (CCD's) were recognized for their potential as an imaging technology almost immediately following their conception in 1970. Twenty years later, they are firmly established as the technology of choice for visible imaging. While consumer applications of CCD's, especially the emerging home video camera market, dominated manufacturing activity, the scientific market for CCD imagers has become significant. Activity of the Jet Propulsion Laboratory and its industrial partners in the area of CCD imagers for space scientific instruments is described. Requirements for scientific imagers are significantly different from those needed for home video cameras, and are described. An imager for an instrument on the CRAF/Cassini mission is described in detail to highlight achieved levels of performance.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: National Aeronautics and Space Administration, Technology 2000, Volume 1; p 294-300
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  • 90
    Publication Date: 2013-08-31
    Description: The Jet Propulsion Laboratory (JPL), with interest in advanced energy storage systems, is involved in the development of a unique lead acid battery design. This battery utilizes the same combination of lead and lead dioxide active materials present in the automobile starting battery. However, it can provide 2 to 10 times the power while minimizing volume and weight. The typical starting battery is described as a monopolar type using one current collector for both the positive and negative plate of adjacent cells. Specific power as high as 2.5 kW/kg was projected for 30 second periods with as many as 2000 recharge cycles.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: National Aeronautics and Space Administration, Technology 2000, Volume 1; p 287-293
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  • 91
    Publication Date: 2013-08-29
    Description: The approach taken by NASA and JPL (Jet Propulsion Laboratory) in the development of a MIL-STD-975 section which contains advanced technology such as Large Scale Integration and Very Large Scale Integration (LSI/VLSI) microelectronic devices is described. The parts listed in this section are recommended as satisfactory for NASA flight applications, in the absence of alternate qualified devices, based on satisfactory results of a vendor capability audit, the availability of sufficient characterization and reliability data from the manufacturers and users and negotiated detail procurement specifications. The criteria used in the selection and evaluation of the vendors and candidate parts, the preparation of procurement specifications, and the status of this activity are discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: ESA, ESA Electronic Components Conference; p 611-614
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  • 92
    Publication Date: 2013-08-31
    Description: The integration of modern CAD tools with formal verification environments require translation from hardware description language to verification logic. A signal representation including both unknown state and a degree of strength indeterminacy is essential for the correct modeling of many VLSI circuit designs. A higher-order logic theory of indeterministic logic signals is presented.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 21 p
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  • 93
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2013-08-31
    Description: In this paper we explore the specification and verification of VLSI designs. The paper focuses on abstract specification and verification of functionality using mathematical logic as opposed to low-level boolean equivalence verification such as that done using BDD's and Model Checking. Specification and verification, sometimes called formal methods, is one tool for increasing computer dependability in the face of an exponentially increasing testing effort.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 14 p
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  • 94
    Publication Date: 2013-08-31
    Description: This paper explores a VLSI architecture for geometrical mapping address computation. The geometric transformation is discussed in the context of plane projective geometry, which invokes a set of basic transformations to be implemented for the general image processing. The homogeneous and 2-dimensional cartesian coordinates are employed to represent the transformations, each of which is implemented via an augmented CORDIC as a processing element. A specific scheme for a processor, which utilizes full-pipelining at the macro-level and parallel constant-factor-redundant arithmetic and full-pipelining at the micro-level, is assessed to produce a single VLSI chip for HDTV applications using state-of-art MOS technology.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Idaho Univ., The 1991 3rd NASA Symposium on VLSI Design; 8 p
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  • 95
    Publication Date: 2013-08-31
    Description: An iterative logic array (ILA) architecture for synchronous sequential circuits is presented. This technique utilizes linear algebra to produce the design equations. The ILA realization of synchronous sequential logic can be fully automated with a computer program. A programmable design procedure is proposed to fullfill the design task and layout generation. A software algorithm in the C language has been developed and tested to generate 1 micron CMOS layouts using the Hewlett-Packard FUNGEN module generator shell.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 12 p
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  • 96
    Publication Date: 2013-08-31
    Description: This paper introduces an improved method for designing the class of CMOS VLSI asynchronous sequential circuits introduced in the paper by Sterling R. Whitaker and Gary K. Maki, 'Self Arbitrated VLSI Asynchronous Circuits.' Of main interest here is the simple design by inspection rules that arise from these circuits. This paper presents a variation on these circuits which reduces the number of transistors required.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 10 p
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  • 97
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2013-08-31
    Description: Hardware description languages such as VHDL have evolved to aid in the design of systems with large numbers of elements and a wide range of electronic and logical abstractions. For high performance circuits, behavioral models may not be able to efficiently include enough detail to give designers confidence in a simulation's accuracy. One option is to provide a link between the VHDL environment and a transistor level simulation environment. The coupling of the Vantage Analysis Systems VHDL simulator and the NOVA simulator provides the combination of VHDL modeling and transistor modeling.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 5 p
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  • 98
    Publication Date: 2013-08-31
    Description: The iterative logic array (ILA) is introduced as a new architecture for asynchronous sequential circuits. This is the first ILA architecture for sequential circuits reported in the literature. The ILA architecture produces a very regular circuit structure. Moreover, it is immune to both 1-1 and 0-0 crossovers and is free of hazards. This paper also presents a new critical race free STT state assignment which produces a simple form of design equations that greatly simplifies the ILA realizations.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 14 p
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  • 99
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2013-08-31
    Description: A constant current source has been designed which makes use of on chip electrically erasable memory to adjust the magnitude and temperature coefficient of the output current. The current source includes a voltage reference based on the difference between enhancement and depletion transistor threshold voltages. Accuracy is +/- 3% over the full range of power supply, process variations, and temperature using eight bits for tuning.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1991 3rd NASA Symposium on VLSI Design; 9 p
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  • 100
    Publication Date: 2013-08-31
    Description: The use of formal methods to verify the correctness of digital circuits is less constrained by the growing complexity of digital circuits than conventional methods based on exhaustive simulation. This paper briefly outlines three main approaches to formal hardware verification: symbolic simulation, state machine analysis, and theorem-proving.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Idaho Univ., The 1991 3rd NASA Symposium on VLSI Design; 11 p
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