Showing papers on "Ka band published in 1999"
TL;DR: In this paper, a low-loss Ka-band phase shifter using RF MEMS capacitive switches is demonstrated, achieving an average insertion loss of 2.25 dB with better than 15dB return loss.
Abstract: As the need for low-loss phase shifters increases, so does the interest in radio frequency (RF) MEMS as a solution to provide them. In this paper, progress in building low loss Ka-band phase shifters using RF MEMS capacitive switches is demonstrated. Using a switched transmission line 4-bit resonant phase shifter, an average insertion loss of 2.25 dB was obtained with better than 15-dB return loss, a similar 3-bit phase shifter produced an average insertion loss of 1.7 dB with better than 13-dB return loss. Both devices had a phase error of less than 13/spl deg/ in the fundamental states. To our knowledge, these devices represent the lowest loss Ka-band phase shifters reported to date.
145 citations
13 Jun 1999
TL;DR: In this paper, the performance of low-loss, planar baluns specifically designed for MMIC applications operating in the 15 to 40 GHz frequency range was described. But the performance was not discussed.
Abstract: The performance of low-loss, planar baluns, specifically designed for MMIC applications operating in the 15 to 40 GHz frequency range, are described. The baluns are realized in both microstrip and CPW configurations with an insertion loss as low as 0.3 dB per balun. This is the lowest reported loss for a monolithic balun operating at these frequencies. These baluns are truly planar with no requirement for multiple dielectric or metal layers.
71 citations
TL;DR: In this article, the authors used a neural network to estimate median particle size and peak number concentration in ice-phase clouds composed of dry crystals or aggregates in the Maritime Continent Thunderstorm Experiment.
Abstract: Multifrequency radar measurements collected at 2.8 (S band), 33.12 (Ka band), and 94.92 GHz (W band) are processed using a neural network to estimate median particle size and peak number concentration in ice-phase clouds composed of dry crystals or aggregates. The model data used to train the neural network assume a gamma particle size distribution function and a size–density relationship having decreasing density with size. Results for the available frequency combinations show sensitivity to particle size for distributions with median volume diameters greater than approximately 0.2 mm. Measurements are presented from the Maritime Continent Thunderstorm Experiment, which was held near Darwin, Australia, during November and December 1995. The University of Massachusetts—Amherst 33.12/94.92-GHz Cloud Profiling Radar System, the NOAA 2.8-GHz profiler, and other sensors were clustered near the village of Garden Point, Melville Island, where numerous convective storms were observed. Attenuation losses...
61 citations
TL;DR: The evolution of Ka band geostationary Earth orbit (GEO) satellite communications until the present stage of development of systems for direct-to-user (DTU) provision of interactive multimedia services worldwide is surveyed.
Abstract: This paper discusses system and technology aspects crucial to the development of satellite communications at Ka band (20-30 GHz) and beyond. It surveys the evolution of Ka band geostationary Earth orbit (GEO) satellite communications until the present stage of development of systems for direct-to-user (DTU) provision of interactive multimedia services worldwide. Then it discusses the attenuation problem and main technical issues of this new technology. Finally, it provides a view on experiments and technological developments at extremely high-frequency (EHF) bands.
54 citations
TL;DR: In this article, a 38 GHz push-push oscillator based on low-cost state-of-the-art silicon bipolar junction transistors (BJTs) with transit frequencies of approximately 25 GHz is presented.
Abstract: In this work, we present a 38 GHz push-push oscillator based on low-cost state-of-the-art silicon bipolar junction transistors (BJTs) with transit frequencies of approximately 25 GHz. The push-push principle allows the extension of the usable frequency range of the well-established silicon bipolar technology (with its specific advantages, as, for example, a low 1/f-noise) into the K and the Ka bands. The circuitry has been fabricated in thin film technology on a 10-mil alumina substrate. The output power of the oscillator is -11.5 dBm with a single-sideband phase noise of -80 dBc/Hz at an offset frequency of 100 kHz.
51 citations
TL;DR: In this paper, a millimeter-wave H-plane waveguide T-junctions and modified inductive window bandpass filters are used to obtain the generalized scattering matrices of the building blocks and a complete systematic optimization procedure leads to the desired diplexer/multiplexer design.
Abstract: Millimeter-wave H-plane diplexers/multiplexers are designed using modified H-plane waveguide T-junctions and modified inductive window bandpass filters. Modeling of the diplexers/multiplexers are performed using the full-wave mode-matching method to obtain the generalized scattering matrices of the building blocks and by the cascading procedure to provide the overall frequency response. A complete systematic optimization procedure leads to the desired diplexer/multiplexer design. The validity of employing the modified H-plane T-junctions in the diplexer/multiplexer configurations are demonstrated by the design examples. A millimeter-wave Ka upper band diplexer based on the simulated results was built and tested. Without any tuning, excellent experimental results are obtained, which verified the full-wave mode-matching-based precise design.
50 citations
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02 Nov 1999
TL;DR: In this article, a flat-plate dual-band array antenna is described, which comprises two flat plate arrays of single band antenna elements, each of which operates in a different frequency band.
Abstract: A flat-plate dual band array antenna is described which comprises two flat plate arrays of single band antenna elements, each of which operates in a different frequency band. The two flat plate arrays are positioned one above the other, with areas in the upper flat plate array being removed in order that the antenna elements in the lower flat plate array can radiate through the upper flat plate array. The geometric arrangement of the antenna elements is such that distribution networks for the antenna elements can be accommodated in the limited space available. Dual band flat-plate array feeds for a reflector antenna are also described. These use at least two flat-plate arrays that are positioned one above the other. Again regions in the upper flat-plate array are removed to allow the lower flat-plate to operate through the upper one. The geometric arrangement of the antenna elements in these array feeds is such that transmit and receive beams are provided that have co-incident phase centers and approximately equal beamwidths. The flat plate array antenna and reflector antennas described are particularly useful for subscriber satellite communication systems such as satellite TV, with receive signals being in the Ku band and transmit signals being in the Ka band.
44 citations
11 Jul 1999
TL;DR: In this paper, preliminary design of simple antennas to give approximately uniform illumination of the Earth from low-Earth orbit (LEO) satellites in the 20/30 GHz band is outlined.
Abstract: Preliminary design of simple antennas to give approximately uniform illumination of the Earth from low-Earth orbit (LEO) satellites in the 20/30 GHz band is outlined. Three designs are compared for a satellite with an altitude of 800-km. As the satellite altitude decreases it becomes increasingly difficult to obtain the desired wide beamwidth using horn antennas and some improvement may be obtained using a small reflector.
33 citations
TL;DR: In this paper, a low-phase-noise 28.65 GHz oscillator has been demonstrated using a planar resonator, and the resonator is micromachined close to the transistor and has an unloaded Q of 460.
Abstract: A low-phase-noise 28.65 GHz oscillator has been demonstrated using a planar resonator. The resonator is micromachined close to the transistor and has an unloaded Q of 460. The oscillator uses a commercially available high electron mobility transistor (HEMT) for the active device, and results in an output power of 0.6 dBm with a 5.7% DC-RF efficiency. The measured phase noise is -92 dBc/Hz at a 100 kHz offset frequency and -122 dBc/Hz at 1 MHz offset frequency. This is compared with a low-Q planar design showing a 10 dB improvement in phase noise. The micromachined resonator is competitive with other hybrid nonplanar technologies, such as dielectric resonators.
26 citations
13 Jun 1999
TL;DR: In this article, demonstrated results for a 4 W, 16 dB gain Ka-band quasi-optical (QO) amplifier with a 13 element two-sided active array with a hard-horn feed are presented.
Abstract: This paper reports on demonstrated results for a 4 W, 16 dB gain Ka-band Quasi-Optical (QO) amplifier. This amplifier consists of a 13 element two-sided active array with a hard-horn feed. Excess heat is removed via a metal carrier integrated into the array. Each unit-cell consists of patch antennas, cascaded MMIC amplifiers and a unique through-thick-plate coupler. Performance and construction details are discussed. Preliminary results from a 45 element design are also included.
24 citations
13 Jun 1999
TL;DR: In this paper, a high power broadband monolithic power amplifier operating from 29 to 32 GHz was presented for Ka-band ground terminal applications using 0.15 /spl mu/m InGaAs/AlGaA/GaAs pseudomorphic HEMT (PHEMT) devices.
Abstract: A high power broadband monolithic power amplifier operating from 29 to 32 GHz is presented for Ka-band ground terminal applications. Using 0.15 /spl mu/m InGaAs/AlGaAs/GaAs pseudomorphic HEMT (PHEMT) devices, the two stage power amplifier on 4 mil GaAs substrate demonstrated greater than 16 dB small signal gain and 32 dBm (1.6 watts) power. The amplifier attained peak output power of 33 dBm (2 watts) and power added-efficiency of 27%. At this power level, the amplifier exhibited power densities in excess of 620 mW/mm. Performance capabilities of the HEMT power amplifiers at millimeter-wave frequencies is documented in terms of power densities at 1 dB compression and at saturation, as well as power-added efficiency.
TL;DR: An aeronautical measurement campaign for the satellite channel at the K band and an aer onautical multimedia service demonstration campaign for high data rate satellite services at theK/Ka band aim to provide highData rate services for all kinds of mobile terminals.
Abstract: An aeronautical measurement campaign for the satellite channel at the K band and an aeronautical multimedia service demonstration campaign for high data rate satellite services at the K/Ka band aim to provide high data rate services for all kinds of mobile terminals.
TL;DR: A new type offset reflector antenna fed through an equal phase-shift active array is proposed, allowing traffic variation among beams without loss of power efficiency.
Abstract: This paper presents a new power-sharing multiple-beam mobile satellite system concept in the Ka band. A wide allocated bandwidth and a large amount of frequency reuse based on hundreds to thousands of small spot beams will allow us to draw a drastically new mobile satellite systems concept in the Ka band. At first, requirements for beam size on the surface of the Earth for various signal transmissions are considered. Based on these requirements, Ka band geostationary systems with 3.5 and 10 m satellite antennas are shown. If the number of beams is hundreds to thousands, it is not appropriate to assume a fixed power transmitter for each beam because the traffic in each beam is not uniform or static. In order to cope with this multiple-beam-varying traffic problem, this paper proposes a new type offset reflector antenna fed through an equal phase-shift active array. The proposed active array consists of hundreds to thousands of equal phase-shift elements. Features and simulated performances of the proposed transmitting antenna are presented. Preliminary experimental results from a 2.1 m reflector fed through 332 hollow elements are also shown. Since each beam commonly utilizes all active array elements, power sharing among beams is possible, allowing traffic variation among beams without loss of power efficiency.
13 Jun 1999
TL;DR: In this paper, a compact Ka-band MMIC low noise amplifiers were developed with high gain, low VSWR and low power dissipation using 0.12 /spl mu/m InP HEMT technology.
Abstract: Compact Ka-Band MMIC low noise amplifiers have been developed with high gain, low VSWR and low power dissipation using 0.12 /spl mu/m InP HEMT technology. A five stage single-ended LNA achieved 40 dB of gain and a 1.4 dB average noise figure over the 27-30 GHz band with an input return loss in excess of 15 dB. The 3/spl times/1 mm/sup 2/ MMIC consumes less than 40 milliwatts of dc power.
TL;DR: In this article, a micromachined cavity oscillator (MCO) was proposed for low-cost mm-wave frequency sources, which showed a phase noise of -113 dBc/Hz at 1 MHz offset, which is an 18dB improvement over an MMIC free-running oscillator.
Abstract: Low-cost stable oscillators with good phase noise performance are in high demand for emerging millimeter (mm)-wave commercial applications. To overcome the problems of conventional DROs and cavity oscillators at mm-waves, a new type of oscillator based on micromachining techniques is developed at Ka-band. A cavity resonator is fabricated using micromachining techniques and is employed to stabilize a 33-GHz monolithic microwave integrated circuit (MMIC) oscillator. A micromachined cavity oscillator (MCO) showed a phase noise of -113 dBc/Hz at 1 MHz offset, which is an 18-dB improvement over an MMIC free-running oscillator (FRO). This work demonstrates the great potential of MCO for low-cost mm-wave frequency sources.
13 Jun 1999
TL;DR: In this paper, the design and performances of a GaAs PIN diode and a reflected-type MMIC phase shifter in Ka-band were described. But the performance of phase shifters was not evaluated.
Abstract: This paper describes the design and performances of a GaAs PIN diode and a reflected-type MMIC phase shifter in Ka-band. With optimized geometries and fabrication process, the GaAs PIN diode has shown the highest fmax so far. Excellent performances of MMIC phase shifters have also been obtained.
TL;DR: In this article, a three-stage MMIC low-noise amplifier with 0.15/spl times/120 /spl mu/m/sup 2/ AlGaAs-InGaAs pHEMTs has been developed for use in active phased-array receiver modules.
Abstract: A Ka-band three-stage monolithic microwave integrated circuit (MMIC) low-noise amplifier using source inductors with different values for each stage has been developed for use in active phased-array receiver modules. The three-stage MMIC low-noise amplifier with 0.15/spl times/120 /spl mu/m/sup 2/ AlGaAs-InGaAs pHEMTs has achieved a noise figure of 1.6 dB, a gain of 22.8 dB, an input return loss of 29 dB, and an output return loss of 24 dB at 28 GHz by optimizing the values of source inductors for each stage. The minimum noise figure was 1.3 dB at 30 GHz.
01 Jan 1999
TL;DR: A large number of new satellite systems for broadband multimedia communications will be developed for fixed, portable and mobile terminals within the next few years, in order to satisfy the expanded bandwidth requirements and to avoid the restricted capacity of lower frequency bands as discussed by the authors.
Abstract: Within the next years, a large number of new satellite systems for broadband multimedia communications will be developed for fixed, portable and mobile terminals. In order to satisfy the expanded bandwidth requirements and to avoid the restricted capacity of lower frequency bands, these systems will operate at frequency bands above 18 GHz.
13 Jun 1999
TL;DR: In this article, performance repeatability, thermal properties, and effects of biasing are studied on two Ka-band quasi-optical slot amplifier arrays fabricated with commercial MMICs on 254/spl mu/m aluminum-nitride substrates.
Abstract: Performance repeatability, thermal properties, and effects of biasing are studied on two Ka-band quasi-optical slot amplifier arrays fabricated with commercial MMICs on 254-/spl mu/m aluminum-nitride substrates. The unit cells are arranged in a 6/spl times/6 triangular lattice to suppress sidelobes. The amplifier arrays have peak small-signal gains of 2.1 dB at 31.02 GHz and 6.5 dB at 31.40 GHz, respectively.
13 Jun 1999
TL;DR: In this article, a push-pull power MMIC operating over the 24 to 38 GHz band is presented, employing a CPW circuit medium, with an output power of 0.46 watt with a power-added efficiency of 26% at 25 GHz.
Abstract: A push-pull power MMIC operating over the 24 to 38 GHz band is presented. Employing a CPW circuit medium, this IC has demonstrated an output power of 0.46 watt with a power-added efficiency of 26% at 25 GHz. The associated power gain was 14.6 dB. The size of this chip is a very compact 1.5/spl times/2.55 mm/sup 2/.
01 Oct 1999
TL;DR: In this paper, a measurement set up developed for millimeter wave characterization of passive or active quasi optical components such as filters, polarizers, amplifiers or multipliers is presented.
Abstract: This paper presents a measurement set up developed for millimeter wave characterization of passive or active quasi optical components such as filters, polarizers, amplifiers or multipliers. The main quasi optical elements of this bench are the focusing horns which allow guided wave coupling to the quasi optical components. These horns are designed using the Gaussian beam theory and FDTD software on a personal computer. The quasi optical measurements are performed according to a TRL calibration method in the Ka band for passive circuit characterization such as a dielectric slab. These measurements give the scattering matrix of quasi optical components which can be used for simulation in classical CAD software.
09 Aug 1999
TL;DR: In this article, the authors focused on characteristics of rain-induced attenuation at Ka-band measured over the period 1994-1997 with the Advanced Communications Technology Satellite (ACTS) in Vancouver (Canada).
Abstract: This paper focuses on characteristics of rain-induced attenuation at Ka-band measured over the period 1994-1997 with the Advanced Communications Technology Satellite (ACTS) in Vancouver (Canada). Event-based analyses of fading are performed and examples of the instantaneous 30/20 GHz frequency-scaling ratio are presented. Long-term cumulative statistics of rain rate as derived from raingauge measurements, along with annual attenuation statistics at 20 and 30 GHz are provided. Finally, rain rate and attenuation statistics are compared with ITU-R models and aspects related to local climatic characteristics are considered, aiming to improve the predictions of attenuation due to rain.
11 Jul 1999
TL;DR: In this paper, a one-meter diameter, 32 GHz active microstrip reflectarray capable of electronic beam steering has been studied, where the 15,500 element array consists of microstrip patch antennas, microstrip phase shifters, and DC bias lines.
Abstract: A one-meter diameter, 32 GHz active microstrip reflectarray capable of electronic beam steering has been studied. The 15,500 element array consists of microstrip patch antennas, microstrip phase shifters, and DC bias lines. Specifically, the study focused on the solid-state devices and DC bias layouts for scanning the beam linearly 45/spl deg/ from boresight using 2-bit phase shifters. Three configurations are recommended for the reflectarray with integrated 2-bit phase shifters where the total substrate and cladding mass varies from 8 kg to 14 kg. Additionally, DC power requirements for p-i-n diodes in 1-bit, 2-bit and 3-bit phase shifting circuits are approximately 19 W, 19 W, and 39 W, respectively. The DC power requirement for phase shifters using passive MESFETs is much less than 1 W.
TL;DR: In this article, the performance, thermal properties, and effects of biasing were studied on two Ka-band quasi-optical slot-antenna amplifier arrays, fabricated with commercial monolithic microwave integrated circuits (MMIC's) on aluminum-nitride substrates.
Abstract: Repeatability of performance, thermal properties, and effects of biasing are studied on two Ka-band quasi-optical slot-antenna amplifier arrays, fabricated with commercial monolithic microwave integrated circuits (MMIC's) on aluminum-nitride substrates. The unit cells are arranged in a 6/spl times/6 triangular lattice to suppress sidelobes. The amplifier arrays have small-signal gains relative to a free-space through of 2.1 dB at 31.02 GHz and 6.5 dB at 31.40 GHz. The average small-signal gain contributed by the MMIC's is 10 dB. In saturation, the arrays deliver 89 W effective isotropic radiated power (EIRP) or 0.3 W output power at 30.40 GHz and 145 W EIRP or 0.5 W output power at 31.15 GHz.
TL;DR: In this article, the authors present optoelectronic mixing of data signals with a carrier signal in a mode-locked semiconductor laser diode, which is monolithically integrated with an electro-absorption modulator.
Abstract: The authors present optoelectronic mixing of data signals with a carrier signal in a mode-locked semiconductor laser diode. A long Fabry-Perot (FP) laser at 1.5 /spl mu/m, which is monolithically integrated with an electro-absorption modulator, is mode-locked at 19.3 GHz through loss modulation. The gain section of the mode-locked laser is modulated by S-band signals. Modulation sidebands are observed in the optical domain as a result of mixing between the mode-locking and S-band communication signals. Optical up-conversion loss of 2.7 and 1.4 dB is measured for the LSB and USB. The measured spurious-free dynamic range is as high as 89 dB.Hz/sup 2/3/.
01 Feb 1999
TL;DR: In this article, an analysis is presented relating rain attenuation statistics to BEP performance of Earth-space links subjected to interference by an adjacent satellite operating in the same frequency band, and a systematic design method is proposed that takes into account the BER objectives specified by the ITU for the design of satellite links.
Abstract: An analysis is presented relating rain attenuation statistics to BEP performance of Earth-space links subjected to interference by an adjacent satellite operating in the same frequency band. A systematic design method is proposed that takes into account the BER objectives specified by the ITU for the design of satellite links. Numerical results based on the proposed method have been obtained to investigate the combined effect of rain and interference for the Ku and Ka bands and for various data rates and climatic zones.
01 Jan 1999
TL;DR: Simulation results showing that performance can differ significantly between amplifiers with different compression characteristics are presented, suggesting alternative specifications for SSPA performance and system tradeoffs including adjacent channel and intersymbol interference are discussed.
Abstract: Common industry practise is to specify transmitter output power at 1 dB gain compression. This paper presents simulation results showing that performance can differ significantly between amplifiers with different compression characteristics. Alternative specifications for SSPA performance and system tradeoffs including adjacent channel and intersymbol interference, among others, are discussed.
12 Apr 1999
TL;DR: This paper describes pseudomorphic HEMT-based MMIC for K- to Ka-band applications for use in wireless communications such as LMDS, miniaturized in size by methods including electromagnetic simulation and a lumped element designing approach.
Abstract: This paper describes pseudomorphic HEMT-based MMIC for K- to Ka-band applications for use in wireless communications such as LMDS. A developed LNA exhibits a low noise figure of 1.4 dB and an HPA provides a 31.6 dBm output power at 30 GHz and another HPA 24.6 dBm at 40 GHz. Each chip is miniaturized in size by methods including electromagnetic simulation and a lumped element designing approach.
01 Jan 1999
TL;DR: In this article, the authors describe the design and development of a system to provide a reference signal with the highest possible frequency stability for both long-term, short-term and phase noise, at an antenna (DSS 25) that is remote from the frequency standards room at SPC-10 at the Goldstone site.
Abstract: New radio science experiments, including a gravitational wave search and several atmospheric occultation studies, are planned for the Cassini Ka-band experiment. These experiments are made possible by reduced solar-induced phase fluctuations at the high-frequency (32 GHZ) of the radio link between the earth and the spacecraft. In order to match the improved link performance, a significant upgrade is under way to improve the frequency stability capabilities of NASA's Deep Space Network (DSN). Significant improvements are being undertaken in many areas, including antenna vibration and (wet) tropospheric calibration, in addition to frequency generation and distribution. We describe here the design and development of a system to provide a reference signal with the highest possible frequency stability for both long-term, short-term, and phase noise, at an antenna (DSS 25) that is remote from the frequency standards room at SPC-10 at the Goldstone site. The new technologies were developed in order to meet the very tight requirements. They are: 1) a Stabilized Fiber-Optic Distribution Assembly (SFODA) that includes active compensation of thermal variations to transfer long-term stability over 16 km of ordinary fiber-optic cable, and 2) a Compensated Sapphire Oscillator (CSO) that provides short-term performance in a cryocooled sapphire oscillator with ultra-high short-term stability and low phase noise.