Showing papers on "Ka band published in 1991"
10 Jun 1991
TL;DR: In this paper, a high-power K/Ka-band MESFET switch monolithic microwave integrated circuit (MMIC) has been developed for use in transmit/receive (T/R) modules.
Abstract: A high-power K/Ka-band MESFET switch monolithic microwave integrated circuit (MMIC) has been developed for use in transmit/receive (T/R) modules. The switch demonstrates 0.2 dB insertion loss compression with 30 dBm input power, 12 dB higher than previously reported for K/Ka-band MESFET switches. Also, no isolation degradation was apparent with up to 28 dBm input power, a 13 dB improvement over the same previously demonstrated switches. A combination of techniques was used to yield higher power handling while preserving low loss and high isolation. These circuit techniques include the use of stacked MESFETs with large peripheries to improve power handling and transmission line transformers to minimize loss and maintain high isolation. >
36 citations
24 Jun 1991
TL;DR: In this article, a dual-screen DSL (double-square-loop) FSS was designed to multiplex the S, X, Ku and Ka frequency bands for the NASA CRAF/CASSINI mission.
Abstract: A dual-screen DSL (double-square-loop) FSS (frequency-selective surface) is designed to multiplex the S, X, Ku and Ka frequency bands for the NASA CRAF/CASSINI mission. Specifically. this four-frequency FSS reflects the X (7.2/8.4-GHz) and the Ka (32/34-GHz) waves but transmits the S-band (2.3-GHz) and the Ku-band (13.8-GHz) waves. The dual-screen DSL FSS may be operated for both transverse electric and transverse magnetic (or circular) polarizations and for incident angles steered from normal to 45 degrees . This FSS was fabricated using the conventional PWB technique. >
30 citations
Patent•
24 Jan 1991
TL;DR: In this article, a radar detector for use in a motor vehicle employs amplitude detection to sense the presence of radar signals commonly used to monitor the speed of such motor vehicles, where amplitude signals are generated by down-converting received signals using a series of mixers, one of which is swept to insure signal detection, and compared to a threshold which is controlled such that noise is detected by the comparison on average a selected period of time.
Abstract: A radar detector for use in a motor vehicle employs amplitude detection to sense the presence of radar signals commonly used to monitor the speed of such motor vehicles. Amplitude signals are generated by down-converting received signals using a series of mixers, one of which is swept to insure signal detection, and compared to a threshold which is controlled such that noise is detected by the comparison on average a selected period of time. Detected amplitude signals must persist for a given period of time before they are considered to be potentially valid radar signals. After passing the first test of persistence, the signals are verified by means of frequency modulating the first of the series of mixers, detecting the frequency modulation and correlating the detected frequency modulation to determine whether the signal is valid and if so, to which radar frequency band the signal belongs. A first embodiment of the radar detector monitors the X band (10.475-10.575 Ghz), the Ku band (13.400-13.500 Ghz), the K band (24.025-24.275 Ghz), and the Ka band (34.200-35.200 Ghz) and a second embodiment monitors all of these radar signal bands plus and expanded Ka band (34.200-35.200 Ghz).
29 citations
01 Jan 1991
TL;DR: In this paper, the authors describe a NASA-sponsored program whose objective is to develop a high-efficiency, low-power TWTA (traveling wave tube amplifier) operating at 32 GHz and meeting the requirements for the Cassini Mission to study Saturn, planned for launch in 1995.
Abstract: The authors describe a NASA-sponsored program whose objective is to develop a high-efficiency, low-power TWTA (traveling wave tube amplifier) operating at 32 GHz and meeting the requirements for the Cassini Mission to study Saturn, planned for launch in 1995. The required RF output power of the helix TWT is 10 W, while the DC power from the spacecraft is limited to about 30 W. This performance level will permit the transmission to Earth of all the data produced in the mission. In order to achieve this efficiency, several novel technologies are incorporated into the TWT, including an advanced dynamic velocity taper characterized by a nonlinear reduction in pitch in the output helix section of the TWT and a Lewis-designed multistage depressed collector using copper electrodes treated for secondary electron emission suppression. Preliminary program results are encouraging: RF output power of 10.6 W has been obtained at 14-mA beam current and 5.2-kV helix voltage with overall TWT efficiency exceeding 40%. >
16 citations
20 Oct 1991
TL;DR: In this paper, the performance of monolithic integrated oscillators using submicron InAlAs/InGaAs HEMTs at 35 GHz is presented. And two different types of feedback schemes were employed showing distinct bias tuning features.
Abstract: The performance of monolithic integrated oscillators using submicron InAlAs/InGaAs HEMTs (high electron mobility transistors) at 35 GHz is presented. Two different types of feedback schemes were employed showing distinct bias tuning features. A large-signal analysis was performed to analyze their power characteristics. The dual feedback oscillator had an output power of 8.2 mW and showed a high DC-to-RF efficiency of 36% at 35.6 GHz. >
14 citations
01 Jan 1991
TL;DR: The chip is a fully functional FM-CW radar which detects the doppler frequency shift from reflected objects and is the largest multifunction MMC demonstrated operating at millimeter-wave frequencies.
Abstract: This paper presents the first monolithic single chip FM-CW radar transceiver operating at 40 GHz. The chip is the largest multifunction MMC demonstrated operating at millimeter-wave frequencies. The design implements transmitter receiver, and duplexer functions using a single process InGaAs HEMT technology. The transmitter operates in the frequency range from 37 to 40 GHz and has greater than 12.0 dl3m output power. The receiver converts the signals in the same frequency range to an IF’ frequency of 10 to 100 MHz with 0 dB conversion loss. When integrated with an antenna, the chip is a fully functional FM-CW radar which detects the doppler frequency shift from reflected objects. The paper will describe the design, fabrication, and performance of the chip.
10 citations
TL;DR: In this paper, the performance of LNA (low-noise amplifier) MMICs (monolithic microwave integrated circuits) in Ka-band using only ion-implantation technology is presented.
Abstract: The performance of LNA (low-noise amplifier) MMICs (monolithic microwave integrated circuits) in Ka-band using only ion-implantation technology is presented. Three-stage LNAs fabricated using a high-yield 0.25- mu m ion-implanted process showed a 4.2 dB average noise figure with a 15-dB gain in Ka-band. It is concluded that this relatively inexpensive technology, if maximized for the performance, shows good promise in applications where unit cost is critical and volume is high. >
10 citations
10 Jun 1991
TL;DR: In this paper, a Ka-band solid-state transmitter capable of power greater than 5 W was developed, which consists of an array of 21 elements each driven by a single stage MMIC (monolithic microwave integrated circuit) power amplifier, a MMIC three-stage preamplifier, and a four bit phase shifter.
Abstract: A Ka-band solid-state transmitter capable of power greater than 5 W is being developed. The transmitter consists of an array of 21 elements each driven by a single stage MMIC (monolithic microwave integrated circuit) power amplifier, a MMIC three-stage preamplifier, and a MMIC four bit phase shifter. The design of the array, measurements of the antenna pattern of the full array, and an electronically beam steered subarray are reported. >
9 citations
15 Aug 1991
TL;DR: In this article, a unique experimental method was used to test the beam waveguide antenna at DDS 13 in the Goldstone Deep Space Communications Complex near Barstow, California.
Abstract: A unique experimental method was used to test the beam waveguide (BWG) antenna at Deep Space Station (DDS) 13 in the Goldstone Deep Space Communications Complex near Barstow, California. The methodology involved the use of portable test packages to make measurements of operating noise temperatures and antenna efficiencies (as functions of antenna pointing angles) at the Cassegrain focal point and the final focal point located in a subterranean pedestal room. Degradations caused by the BWG mirror systems were determined by making comparisons of the measured parameters at the two focal points of the antenna. Previous articles were concerned with the design, performance characteristics, and test results obtained with an X-band test package operating at 32 GHz. Noise temperature measurement results are presented for the Ka-band test package in an on-the-ground test configuration.
8 citations
24 Jun 1991
TL;DR: In this paper, the authors describe an antenna system for a proposed multiband communication satellite utilizing five frequency bands, namely, Ka (30/20 GHz), Ku (14/12 GHz), C (6/4 GHz), S (2.6/2.5 GHz), and L (1.6 /1.1 GHz).
Abstract: The authors describe an antenna system for a proposed multiband communication satellite utilizing five frequency bands. Ka (30/20 GHz), Ku (14/12 GHz), C (6/4 GHz), S (2.6/2.5 GHz), and L (1.6/1.5 GHz). Seven beam configurations have been created, including three multibeams, three shaped beams, and a circular single beam. The authors present feasibility studies on three kinds of frequency selective surfaces, the key technology for constructing this satellite. One is a novel frequency-selective subreflector with two separate focal feed positions. The others are planar frequency selective surfaces specified with low losses and wide reflection bandwidths. Measured data suggest the reliable achievement of low-loss frequency sharing and the possibility of realizing an advanced communication satellite. >
7 citations
01 May 1991
TL;DR: The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal.
Abstract: The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, etc., combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) Project by the implementation of optimal processing schemes derived through the use of the Rain Attenuation Prediction Model and nonlinear Markov filtering theory.
TL;DR: In this article, a frequency selective subreflector with two separate focal positions for a 30/20 GHz offset Gregorian reflector antenna was developed for a bandwidth exceeding 3 GHz in the 20 and 30 GHz band, the measured losses are 0.7 and 1.5 dB, respectively.
Abstract: A frequency selective subreflector with two separate focal fed positions for a 30/20 GHz offset Gregorian reflector antenna is newly developed. For a bandwidth exceeding 3 GHz in the 20 and 30 GHz band, the measured losses are 0.7 and 1.5 dB, respectively.
01 Oct 1991
TL;DR: A concept for a future advanced mobile satellite communications system using a geostationary satellite using a multiple spotbeam antenna, onboard beam interconnection, and millimeter-wave and Ka-band components are required.
Abstract: A concept for a future advanced mobile satellite communications system using a geostationary satellite is described. In the satellite of this system, a multiple spotbeam antenna, onboard beam interconnection, and millimeter-wave and Ka-band components are required. The configuration of the payloads of Japan's COMETS (Communications and Broadcasting Engineering Test Satellite) for advanced mobile satellite communication experiments is also described. The transponder has an IF filter bank and a SCPC/TDM (signal-carrier-per-channel/time-dimension multiplexing) regenerative modem for beam interconnection.<>
10 Jul 1991
TL;DR: In this article, a comparison between two high-speed fiber-optic (FO) link architectures is presented, where experiments were performed on two reactively matched links, one operating from 18.5 to 19.0 GHz and the other at 0.1 GHz.
Abstract: A comparison between two high-speed fiber-optic (FO) link architectures is presented. Experiments were performed on two reactively matched links, one operating from 18.5 to 19.0 GHz and the other at 0.5 to 1 GHz and then subsequently upconverted to 18.0 GHz. Both links were fully characterized analytically and experimentally. It is demonstrated that, for high-frequency operation, the best configuration results from the separation of the data and carrier signals. When these signals are sent over separate links, this architecture is called T/R level data mixing. Improvements are seen in gain (>30 dB), noise figure (>30 dB), and dynamic range (>40 dB) when this architecture is implemented. >
15 May 1991
TL;DR: In this article, an X/Ka-band dichroic plate is proposed for simultaneously receiving X-band and Ka-band in the DSS-13 Beam Waveguide Antenna.
Abstract: An X-/Ka-band dichroic plate is needed for simultaneously receiving X-band and Ka-band in the DSS-13 Beam Waveguide Antenna. The plate is transparent to the allocated Ka-band downlink (31.8-32.3 GHz) and the frequency band for the Mars Observer Ka-band Beacon Link Experiment (KABLE) (33.6-33.8 GHz), while at the same time reflecting the X-band downlink (8.4-8.5 GHz). The design is made using a computer program for dichroic plates with rectangular holes. The theoretical performance of the X-/Ka-band dichroic plate is presented. A study of the grating lobe problem is also included in this article.
TL;DR: In this paper, a cross-bar mixer operating at the atmospheric window centered at 33 GHz was designed, developed and tested as a forerunner to mixers operating at atmospheric windows centred at higher frequencies.
Abstract: Many receivers operating at millimetre wavelengths utilise a frequency downconverter as their first stage. A rugged, low-conversion loss and simplified cross-bar mixer operating at the atmospheric window centered at 33 GHz was designed, developed and tested as a forerunner to mixers operating at atmospheric windows centred at higher frequencies. The cross-bar mixer exhibits a conversion loss of less than 5 dB over a bandwidth of 2 GHz. Design and optimisation procedures of the mixer are outlined.
15 Aug 1991
TL;DR: In this paper, the design and predicted performance of the microwave layout for three band operation of the beam waveguide antenna of the Deep Space Station (DSS) was described and three pedestal room microwave candidate layout designs were produced for simultaneous X/S and X/Ka band operation.
Abstract: The design and predicted performance is described of the microwave layout for three band operation of the beam waveguide antenna Deep Space Station 13 Three pedestal room microwave candidate layout designs were produced for simultaneous X/S and X/Ka band operation One of the three designs was chosen based on given constraints, and for this design the microwave performance was estimated
01 Jan 1991
TL;DR: In this paper, the performance of gold and superconducting Ka-band microstrip antennas at various temperatures was evaluated using a closed cycle gas cooled refrigerator in a far field range.
Abstract: The measurement of cryogenic antennas poses unique logistical problems since the antenna under test must be embedded in a cooling chamber. A method of measuring the performance of cryogenic microstrip antennas using a closed cycle gas cooled refrigerator in a far field range is described. Antenna patterns showing the performance of gold and superconducting Ka-band microstrip antennas at various temperatures are presented.
15 Apr 1991
TL;DR: In this paper, coupled tapered slot-line antennas (CTSL) are proposed and investigated experimentally, they are easy to be connected to the monolithic integrated circuit and the tested results of the samples at X-band and Ka-band show that the endfire beam can be controlled in designing by means of shaping the taper.
Abstract: Two new kinds of coupled tapered slot-line antennas (CTSL) are proposed and investigated experimentally, they are easy to be connected to the monolithic integrated circuit. The tested results of the samples at X-band and Ka-band show that the endfire beam can be controlled in designing by means of shaping the taper, and a wider bandwidth can be performed.
20 Oct 1991
TL;DR: In this article, a monolithic transmitter consisting of a voltage controlled oscillator and power amplifier has been successfully demonstrated for Ka-band high volume system applications (smart munitions) using nominally quarter micron MESFET technology.
Abstract: A monolithic transmitter consisting of a voltage controlled oscillator and power amplifier has been successfully demonstrated for Ka-band high volume system applications (smart munitions) using nominally quarter micron MESFET technology. The results show that this technology is able to deliver good performance without compromising on yield and cost in Ka-band. With improvement in 1/f noise in HEMTs (high electron mobility transistors), it will be a viable candidate for VCOs in the future. Also shown is a unified design approach for VCOs and power amplifiers using small signal analysis. >
17 Dec 1991
TL;DR: In this article, a fade countermeasure system is realized using spread spectrum techniques in the 20/30 GHz bands of the OLYMPUS satellite, which interconnects up to four sites and offers continuous-presence video, audio and computer data facilities.
Abstract: In the 20/30 GHz bands the fading of a satellite channel can be severe due to precipitation. In the DICE project a fade countermeasure system is realised using spread spectrum techniques. An adaptive remultiplexer has been developed which varies the spreading ratio depending on the monitored channel quality. The transmitted bandwidth remains constant as the data rate varies according to the fading depth. The fade countermeasure system is applied in a multi-point video conferencing trial over the 20/30 GHz communications payload of ESA's OLYMPUS satellite. The DICE system interconnects up to four sites and offers continuous-presence video, audio and computer data facilities. The video conferencing system is based on small satellite earth stations with 1.5 m antennas and easily transportable units (rollabouts) for the video, audio and graphics facilities.
TL;DR: A series of electron cyclotron masers (ECMs) has been designed and successfully operated in the frequency range of 6 to 200 GHz over the past 10 years at Strathclyde University as discussed by the authors.
Abstract: A series of electron cyclotron masers (ECMs) has been designed and successfully operated in the frequency range of 6 to 200 GHz over the past 10 years at Strathclyde University. The current Mk. VI ECM operated between 35–200 GHz, the TE 0 1 0 mode (35.2 GHz) being the lowest order cavity mode excited. Investigation of this ECM and quasi-optical converter combination was made to establish to what extent a Gaussian beam could be produced from the TE 0 1 0 gyrotron cavity mode.
20 Oct 1991
TL;DR: The high yield number obtained from this high level integration MMIC of multifunctional chips indicates the maturity of the quarter micron GaAs MESFET technology.
Abstract: A monolithic Ka-band transmitter using 0.25 mu m GaAs MESFET technology has been developed. This MMIC chip consists of a VCO and a power amplifier. An output power of 21.5 dBm with a tuning range of 600 MHz centered at 35.8 GHz has been achieved. The average RF yield of this transmitter chip, using the specifications of 17 dBm output power and 400 MHz tuning range, is as high as 40%. The high yield number obtained from this high level integration MMIC of multifunctional chips indicates the maturity of the quarter micron GaAs MESFET technology. >
TL;DR: In this paper, a repeatable MBE power MMIC process has been developed for low-cost and high-volume Ka-band applications, and the RF yield under power drive has reached more than 60%.
Abstract: A very repeatable MBE power MMIC process has been developed for low-cost and high-volume Ka-band applications. The RF yield under power drive has reached more than 60%. The power out in a balanced configuration was 300 mW with 18% power added efficiency at 30 GHz.
10 Jul 1991
TL;DR: In this article, a novel type of electrically controlled phase shifter has been designed and realized at 35 GHz, by using a piezoelectric bimorph actuator, and a figure of merit as high as 270 degrees /0.35 dB has been obtained in the Ka band, as well as an insertion loss of less than 0.5 dB including the mismatch of rectangular to dielectric waveguide transition.
Abstract: A novel type of electrically controlled phase shifter has been designed and realized at 35 GHz, by using a piezoelectric bimorph actuator. A figure of merit as high as 270 degrees /0.35 dB has been obtained in the Ka band, as well as an insertion loss of less than 0.5 dB including the mismatch of rectangular to dielectric waveguide transition. Good agreement has been observed between predicted and measured results. >
01 Sep 1991
TL;DR: The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules of a modular Ka-band MMIC microstrip subarray.
Abstract: In a recent technology assessment of alternative communication systems for the space exploration initiative (SEI), Ka-band (18 to 40 GHz) communication technology was identified to meet the mission requirements of telecommunication, navigation, and information management. Compared to the lower frequency bands, Ka-band antennas offer higher gain and broader bandwidths; thus, they are more suitable for high data rate communications. Over the years, NASA has played an important role in monolithic microwave integrated circuit (MMIC) phased array technology development, and currently, has an ongoing contract with Texas Instrument (TI) to develop a modular Ka-band MMIC microstrip subarray (NAS3-25718). The TI contract emphasizes MMIC integration technology development and stipulates using existing MMIC devices to minimize the array development cost. The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules.
TL;DR: The design rationale of the system is described in the paper together with some of the applications and demonstrations that have been transmitted over the Olympus satellite to date.
Abstract: An experimental microterminal satellite data communication system known as CODE has been developed by the European Space Agency with support from universities, research organisations and industry. The system, which operates at ka band, consists of a large number of microterminals with 80 cm diameter antennas which can communicate directly in a mesh network at 64 kbit/s. A central hub station is used for channel allocation and for general monitoring and control of the microterminals. The system supports a wide range of standard personal computers and workstations. The design rationale of the system is described in the paper together with some of the applications and demonstrations that have been transmitted over the Olympus satellite to date.
Journal Article•
TL;DR: In this article, a Ku and Ka dual-band experimental radar was designed and developed for low-altitude target tracking, which is an amplitute-comparison monopulse tracking and guiding radar.
01 Sep 1991
TL;DR: In this paper, the authors describe recent progress in the Ka-band MMIC power amplifier program, and present a pseudomorphic AlGaAs/InGaA/GaAs HEMT device that achieves 400 mW with 25 percent efficiency at the Ka band and 1 W at the higher frequency.
Abstract: This paper describes recent progress in the Ka-band MMIC power amplifier program. New materials, material growth techniques, device designs and circuit design techniques have made it possible to design and fabricate MMIC amplifiers with both high efficiency and high power at Ka-band and higher frequencies. MMIC amplifiers using pseudomorphic AlGaAs/InGaAs/GaAs HEMT devices presently achieve 400 mW with 25 percent efficiency at Ka-band and 1 W, 35 percent efficient amplifiers are being developed.