Showing papers on "Ka band published in 2005"
Patent•
06 Dec 2005TL;DR: In this paper, the authors provided an array antenna with double reflection boards operating at high frequency such as Ka band by operating the helical antenna in axial mode and implementing dual feeding structure.
Abstract: Provided are Circular Polarized Helical Radiation element and its Array Antenna operable in TX band and RX band The circular polarized helical radiation element and its array antenna and the antenna with double reflection boards using that array can operate at TX/RX dual band which is high frequency such as Ka band by operating the helical antenna in axial mode and implementing dual feeding structure The array antenna having a number of radiation elements operable in the both of TX band and RX band, wherein the radiation elements are arrayed on predetermined column lines, each radiation element comprising: a helix for radiating orthogonal circular polarized waves in the different frequency bands wherein the helix is fed at its beginning point and its terminating point; and a wave guide for accommodating the helix
167 citations
TL;DR: In this article, a monolithic SiGe balanced frequency doubler was developed for Ku- and Ka-band applications, and the impact of the parasitic inductor from emitter to ground was also explored to optimize the conversion efficiency of the doubler.
Abstract: High-efficiency monolithic SiGe balanced frequency doublers have been developed for Ku- and Ka-band applications. A novel miniature second harmonic reflector is presented, and the impact of the parasitic inductor from emitter to ground is also explored to optimize the conversion efficiency of the doubler. The Ku-band design presents an output power of 5-6 dBm from 15.4-18 GHz for an input power of 1.5 dBm. DC power consumption is 28 mW and the corresponding power-added efficiency (PAE) is 9.2%. The Ka-band design demonstrates an output power of 10.5 dBm at 36 GHz for an input power of 6 dBm while consuming 114 mW of dc power, which results in a PAE of 6.4%. It also shows high spectral purity operation with the fundamental suppression of 35 dB. To our knowledge, these are the best results for active doublers using any technology
100 citations
TL;DR: In this article, a dual-band reflectarray antenna for future space inflatable structures with thin membranes is presented, where foam layers are inserted below the X and Ka band membranes, allowing broadband CP performance at both bands.
Abstract: Modern space-borne applications require large-aperture antennas having capabilities of low mass and high packaging efficiency to overcome the launch vehicle size and weight restrictions. This paper presents a dual-band reflectarray antenna developed for future space inflatable structures with thin membranes. To offset the effects of the thin-membrane substrates required in the inflatable structure, foam layers are inserted below the X and Ka band membranes, allowing broadband CP performance at both bands. More than 50% efficiencies are achieved at both frequency bands, showing potential for even larger high-gain inflatable antennas for future space applications.
99 citations
01 Jan 2005
TL;DR: A low power Ka-band Doppler radar that can detect human heartbeat and respiration signals is demonstrated and achieves better than 80% detection accuracy at the distance of 2-m with 16-muW transmitted power.
Abstract: A low power Ka-band Doppler radar that can detect human heartbeat and respiration signals is demonstrated. This radar system achieves better than 80% detection accuracy at the distance of 2-m with 16-muW transmitted power. Indirect-conversion receiver architecture is chosen to reduce the DC offset and 1/f noise that can degrade signal-to-noise ratio and detection accuracy. In addition, the radar has also demonstrated the capability of detecting acoustic signals
81 citations
TL;DR: In this article, an integrated low-power low phase-noise Ka-band differential voltage-controlled oscillator (VCO) was developed in a 0.12-/spl mu/m 200-GHz silicon-germanium heterojunction bipolar transistor technology.
Abstract: An integrated low-power low phase-noise Ka-band differential voltage-controlled oscillator (VCO) is developed in a 0.12-/spl mu/m 200-GHz silicon-germanium heterojunction bipolar transistor technology. The use of line inductors instead of transmission lines is demonstrated to be feasible in LC-tuned resonators for Ka-band applications. This VCO can operate from a supply voltage of 1.6-2.5 V. A single-sideband phase noise of -99 dBc/Hz at 1-MHz offset from the carrier frequency of 33 GHz is achieved, together with a VCO figure-of-merit of -183.7 dBc/Hz. The frequency tuning constant of the VCO in the linear regime is -0.547 GHz/V.
39 citations
TL;DR: The L-3 ETI's latest high-power communications Ka-band TWT model, the 8921HP, demonstrated 250-300-W CW output power and 47% minimum overall efficiency with a two-stage collector over 27.5-31 GHz.
Abstract: Recent advancements made in millimeter-wave helix-traveling wave tubes (TWTs) at L-3 Communications Electron Technologies (L-3 ETI), Inc. (formerly Electron Dynamic Devices, Inc. and originally Hughes Electron Dynamics Division), in continuous-wave (CW) output power capability and the overall efficiency of Ka-band and Q-band devices are presented. The 8921HP, L-3 ETI's latest high-power communications Ka-band TWT model, demonstrates 250-300-W CW output power and 47% minimum overall efficiency with a two-stage collector over 27.5-31 GHz. Another Ka-band device, the 8922HP, developed for pulsed radar applications over 33.4-36 GHz, produces 230-W minimum output power over the bandwidth with 49% minimum overall efficiency. This device was developed for pulsed operations but has demonstrated CW power-handling capability up to 270 W. In Q-band, the 8925HP, derived from the current production 120-W Q-band helix-TWT (8905HP), significantly extends the CW output power capability, demonstrating 230-W minimum over 43.5-45.5 GHz. The beam focusing is improved in both the Ka-band and the Q-band TWT models, with saturated radio-frequency beam interception well below 1% of the nominal beam current of 95 mA. The devices can be operated in pulsed mode by using the focus electrode to cut off the beam. The electron gun typically requires a focus electrode voltage of -800 to -900 V with respect to cathode for beam cutoff.
39 citations
TL;DR: In this paper, a 500-W periodic permanent magnet focused coupled-cavity traveling wave tube (TWT) was developed for conduction-cooled amplifier systems, which is being introduced into the commercial satellite communication market.
Abstract: Worldwide demand for high-power amplifiers for digital satellite communication at Ka-band frequencies between 27 and 31 GHz is steadily increasing (2003). Communication and Power Industries (CPI) has developed a 500-W periodic permanent magnet focused coupled-cavity traveling wave tube (TWT) for conduction-cooled amplifier systems, which is being introduced into the commercial satellite communication market. The TWT is capable of greater than 500-MHz instantaneous bandwidth and is cathode voltage tunable from 28.3 to 30 GHz. The TWT may be operated saturated at the 500-W output power level or backed off from saturation in the linear mode. CPI's Satcom Division has integrated the TWT into a conduction-cooled transmitter box suitable for antenna hub-mount applications. The amplifier uses predistortion networks to provide a high degree of linear response when operated in output power back-off mode.
37 citations
01 Jan 2005
TL;DR: In this article, a compact and efficient Ka-band high power amplifier with output power of over 4W at 30GHz and record compact area of 8.63mm/sup 2/ in a Ka band HPA class was reported.
Abstract: We report a compact and efficient Ka-band high power amplifier with output power of over 4W at 30GHz and record compact area of 8.63mm/sup 2/ in a Ka-band high power amplifier (HPA) class. The bias capacitors (/spl sim/80pF) are included inside the MMIC so that it reduces the assembly cost in the package or module. We employed a dual-recessed 0.15/spl mu/m power pHEMT production process and 2mil-substrate technology to achieve high output power with high efficiency and compact design. The output power (CW measurement) is 36.2dBm, and, the gain, 22.5dB, at 30GHz. These results set the benchmark of CW output power per millimeter square area for the reported performance of Ka-band HPA MMICs.
26 citations
16 May 2005
TL;DR: In this article, a Ka-band (37GHz), dual polarization, combined short-pulse scatterometer-radiometer is described, for short distance remote sensing of bare soil and land snow cover and for simultaneous and coincident measurements of observed media microwave reflective and emissive characteristics, under laboratory-control conditions.
Abstract: In this paper Ka-band (37GHz), dual polarization, combined short-pulse scatterometer-radiometer is described, for short distance remote sensing of bare soil and land snow cover and for simultaneous and coincident measurements of observed media microwave reflective and emissive characteristics, under laboratory-control conditions. Developed system is set on a mobile bogie moving on the height of 6.5m along a stationary platform of 26m of length. It allows carry out polarimetric (vv, vh, hh, hv), simultaneous and coincident microwave active-passive measurements of observed surface (soil, soil vegetation, snow and water surface) parameters at angles of incidence from the while of 0-60o.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
25 citations
03 Jul 2005
Abstract: Communication systems for future NASA interplanetary spacecraft require transmitter powers ranging from several hundred watts to kilowatts Several hybrid junctions are considered as elements within a corporate combining architecture for high power Ka-band traveling-wave tube amplifiers (TWTA) This paper presents the computer-aided designs and simulated transmission characteristics of several hybrid circuits for a low loss, high power waveguide combiner
24 citations
01 Aug 2005
TL;DR: In this article, three millimeter-wave power-combining techniques are reviewed, and three architectures for further analyses are chosen for further analysis Although microstrip binary and serial combining are the most straightforward techniques to implement, they generally suffer from excessive circuit loss to maximize combining efficiency, and therefore, they therefore chose three architectures that use low-loss waveguide structures.
Abstract: Millimeter-wave power-combining techniques are reviewed, and three architectures are chosen for further analyses Although microstrip binary and serial combining are the most straightforward techniques to implement, they generally suffer from excessive circuit loss To maximize combining efficiency, we therefore chose three architectures that use low-loss waveguide structures The first architecture is based on non-resonant radial combiners and offers the greatest flexibility in the number of ports combined It may be possible to combine up to 200 monolithic microwave integrated circuits (MMICs) with a combining efficiency >70 percent The second architecture is based on a more conventional corporate combining design using a low-loss waveguide adder Initial simulations indicate an insertion loss of 01 dB per adder, and greater than 30-dB port-to-port isolation may be possible The third architecture is based on an oversized coaxial spatial combiner Although all three architectures offer some flexibility, the approximate MMIC requirements are 1 to 4 W and >55 percent power-added efficiency These power levels are on the upper range for gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) technology, but are expected to be easily achieved with gallium nitride (GaN) The high efficiency, however, seems beyond the reach of GaAs and will require a focused research effort for GaN
15 Nov 2005
TL;DR: In this article, the authors investigate power-combining technology and SSPA architectures that can enable a 120-W, 40 percent power-added efficiency (PAE) SSPA.
Abstract: Motivated by recent advances in wide-bandgap (WBG) gallium nitride (GaN) semiconductor technology, there is considerable interest in developing efficient solidstate power amplifiers (SSPAs) as an alternative to the traveling-wave tube amplifier (TWTA) for space applications. This article documents the results of a study to investigate power-combining technology and SSPA architectures that can enable a 120-W, 40 percent power-added efficiency (PAE) SSPA. Results of the study indicate that architectures based on at least three power combiner designs are likely to enable the target SSPA. The proposed architectures can power combine 16 to 32 individual monolithic microwave integrated circuits (MMICs) with >80 percent combining efficiency. This corresponds to MMIC requirements of 5- to 10-W output power and >48 percent PAE. For the three proposed architectures [1], detailed analysis and design of the power combiner are presented. The first architecture studied is based on a 16-way septum combiner that offers low loss and high isolation over the design band of 31 to 36 GHz. Analysis of a 2-way prototype septum combiner had an input match >25 dB, output match >30 dB, insertion loss 30 dB over the design band. A 16-way design, based on cascading this combiner in a binary fashion, is documented. The second architecture is based on a 24-way waveguide radial combiner. A prototype 24-way radial base was analyzed to have an input match >30 dB (under equal excitation of all input ports). The match of the mode transducer that forms the output of a radial combiner was found to be >27 dB. The functional bandwidth of the radial base and mode transducer, which together will form a radial combiner/divider, exceeded the design band. The third architecture employs a 32-way, parallel-plate radial combiner. Simulation results indicated an input match >24 dB, output match >22 dB, insertion loss 20 dB over the design band. All three architectures utilize a low-loss MMIC amplifier module based on commercial MMIC packaging and a custom microstrip-to-rectangular-waveguide transition. The insertion loss of the module is expected to be 0.45 dB over the design band.
02 Feb 2005
TL;DR: In this paper, the authors describe the unique experimental platform and qualitatively look at first research results for beacon and carrier bent pipe modes for the Australian "FedSat" LEO microsatellite.
Abstract: Previous Ka band communication experiments have been limited to the observation of geostationary satellites, such as ACTS and OLYMPUS, or have been kept commercial in confidence (Iridium). The Ka band payload on the Australian "FedSat" LEO microsatellite has opened up an opportunity to conduct novel Ka band propagation measurements at varying pointing angles, with the additional challenge of precisely tracking large Doppler shifts. This paper describes the unique experimental platform and qualitatively looks at first research results for beacon and carrier bent pipe modes
TL;DR: The Background Emission Anisotropy Scanning Telescope (BEAST) as mentioned in this paper is a millimeter wavelength experiment designed to generate maps offluctuations inthecosmicmicrowave background (CMB).
Abstract: The Background Emission Anisotropy Scanning Telescope (BEAST) is a millimeter wavelength experiment designed to generate maps offluctuations inthecosmicmicrowave background (CMB). The telescope is composed of an off-axis Gregorian optical systemwith a 2.2 mprimary thatfocuses the collected microwave radiation onto an array of cryogenically cooled high electron mobility transistor (HEMT) receivers. This array is composed of six corrugated scalar feed horns in the Q band (38 to 45 GHz) and two more in the Ka band (26 to 36 GHz) with one of the six Q-band horns connected to an ortho-mode transducer for extraction of both polarizations incident on the
TL;DR: The first sky maps from the BEAST (Background Emission Anisotropy Scanning Telescope) experiment were presented in this article, which consists of a 2.2 m off-axis Gregorian telescope fed by a cryogenic millimeter wavelength focal plane consisting of six Q band (40 GHz) and two Ka band (30 GHz) scalar feed horns feeding cryogenic HEMT amplifiers.
Abstract: We present the first sky maps from the BEAST (Background Emission Anisotropy Scanning Telescope) experiment. BEAST consists of a 2.2 m off-axis Gregorian telescope fed by a cryogenic millimeter wavelength focal plane currently consisting of six Q band (40 GHz) and two Ka band (30 GHz) scalar feed horns feeding cryogenic HEMT amplifiers. Data were collected from two balloon-borne flights in 2000, followed by a lengthy ground observing campaign from the 3.8 km altitude University of California White Mountain Research Station. This paper reports the initial results from the ground-based observations. The instrument produced an annular map covering the sky over 33? < ? < 42?. The maps cover an area of 2470 deg2 with an effective resolution of 23' FWHM at 40 GHz and 30' at 30 GHz. The map rms (smoothed to 30' and excluding Galactic foregrounds) is 57 ? 5 ?K (Rayleigh-Jeans) at 40 GHz. Comparison with the instrument noise and correcting for 5% atmospheric attenuation gives a cosmic signal rms contribution of 29 ? 3 ?K (R-J) or 30 ? 3 ?K relative to a Planck blackbody of 2.7 K. An estimate of the actual cosmic microwave background (CMB) sky signal requires taking into account the l space filter function of our experiment and analysis techniques, carried out in a companion paper. In addition to the robust detection of CMB anisotropies, we find a strong correlation between small portions of our maps and features in recent H? maps. In this work we describe the data set and analysis techniques leading to the maps, including data selection, filtering, pointing reconstruction, mapmaking algorithms, and systematic effects.
TL;DR: In this paper, a linear microstrip array and Fresnel lens combination is proposed for Ka-band satellite communications, where medium-power amplifiers are distributed within the array to achieve a high EIRP required for satellite communications.
Abstract: The design of a linear microstrip array and Fresnel lens combination as a potential candidate for Ka-band satellite communications is presented. Medium-power amplifiers are distributed within the array to achieve a high EIRP required for satellite communications. This architecture may be used as an alternative to the conventional horn-fed reflector antenna with a single high-power amplifier.
04 Dec 2005
TL;DR: In this article, a low noise amplifier MMIC chips were used in the module and those chips had been fabricated using 015 /spl mu/m GaAs pHEMT process.
Abstract: A LNA module, integrated microwave assembly was developed for Ka-band communications satellite payload in the frequency range of 296 /spl sim/ 300 GHz The noise figure of the module has been recorded as low as 19dB at ambient temperature The module has been tested over temperature range of -15 /spl sim/ +71/spl deg/C and shows 333dB of gain within 07dBp-o variation as it has the function of gain compensation The mass of the module is 94grams that provides the flexibility in payload assembly Two low noise amplifier MMIC chips were used in the module and those chips had been fabricated using 015 /spl mu/m GaAs pHEMT process This paper describes the design, fabrication and performance of the LNA module This will include the MMIC design, the mechanical design of module, and the design of waveguide-to-microstrip transition
12 Jun 2005
TL;DR: An extremely sensitive Ka band radiometer, operating at a temperature of approximately 15 Kelvin, is being developed for the EC funded FARADAY radio astronomy project as mentioned in this paper, which uses the band 26 to 36 GHz.
Abstract: An extremely sensitive Ka band radiometer, operating at a temperature of approximately 15 Kelvin, is being developed for the EC funded FARADAY radio astronomy project. To maximize the sensitivity of the radiometer lattice-matched indium phosphide HEMT technology has been used: all of the active components of the radiometer, with the exception of the detectors, have been manufactured on a single wafer process. The radiometer, which uses the band 26 to 36 GHz, will be used to make radio maps of the sky from a 32 metre diameter radio telescope. Several new MMICs have been designed, including a 10 GHz bandwidth low noise amplifier with average noise temperature less than 20 K, and a 180/spl deg/ phase switch using low noise HEMTs as the switching elements. Design principles are described, together with a comparison of modelled and measured results.
TL;DR: In this article, a new type of Ka band (26 to 36 GHz) 180 degree phase switch (bi-phase modulator) monolithic microwave integrated circuit has been developed for the EC funded FARADAY radio astronomy project.
Abstract: A new type of Ka band (26 to 36 GHz) 180 degree phase switch (bi-phase modulator) monolithic microwave integrated circuit has been developed for the EC funded FARADAY radio astronomy project. This integral component forms part of a chip set for a very low noise switching radiometer operating at a temperature of approximately 15 K. To maximize the sensitivity of the radiometer lattice-matched indium phosphide HEMT technology has been used: all of the active components of the radiometer, with the exception of the detectors, have been manufactured on a single wafer process. Design principles are described, together with a comparison of modeled and measured results. The results show an average insertion loss of 3.5 dB, return loss of better than 10 dB and an average phase difference close to 170/spl deg//spl plusmn/10/spl deg/ the 26-36 GHz band.
TL;DR: In this paper, a millimeter-wave resonant ring using a traveling TE/sub 01/ wave in an oversized cylindrical waveguide has been developed for high-power tests of accelerator components.
Abstract: A new millimeter-wave resonant ring using a traveling TE/sub 01/ wave in an oversized cylindrical waveguide has been developed for high-power tests of accelerator components. Novel low-loss miter bends with flat mirrors that utilize mode mixing to minimize losses were used in the resonant ring. Low-power measurements show a maximum effective power gain factor that exceeds 35:1 at the operating frequency of 34.272 GHz. Total quality factor is approximately 21400, and the reflection coefficient from the input to the ring resonator is less than 1%.
15 Nov 2005
TL;DR: Proof-of-concept hardware is used to validate power-combining technologies that may enable a 120-W, 40 percent power-added efficiency (PAE) SSPA, and performance estimates of the three proposed architectures are reported.
Abstract: Motivated by recent advances in wide-bandgap (WBG) gallium nitride (GaN) semiconductor technology, there is considerable interest in developing efficient solid-state power amplifiers (SSPAs) as an alternative to the traveling-wave tube amplifier (TWTA) for space applications. This article documents proof-of-concept hardware used to validate power-combining technologies that may enable a 120-W, 40 percent power-added efficiency (PAE) SSPA. Results in previous articles [1-3] indicate that architectures based on at least three power combiner designs are likely to enable the target SSPA. Previous architecture performance analyses and estimates indicate that the proposed architectures can power combine 16 to 32 individual monolithic microwave integrated circuits (MMICs) with >80 percent combining efficiency. This combining efficiency would correspond to MMIC requirements of 5- to 10-W output power and >48 percent PAE. In order to validate the performance estimates of the three proposed architectures, measurements of proof-of-concept hardware are reported here.
TL;DR: A Ka-band backscatter model and an algorithm for measurement of the wind speed and direction over the sea surface by a frequency-modulated continous-wave radar demonstrator system operated in scatterometer mode have been developed.
Abstract: A Ka-band backscatter model and an algorithm for measurement of the wind speed and direction over the sea surface by a frequency-modulated continous-wave radar demonstrator system operated in scatterometer mode have been developed. To evaluate the proposed algorithm, a simulation of the wind vector retrieval has been performed.
Patent•
14 Oct 2005
TL;DR: In this article, two low-noise amplifiers (LNA) operating in X band and a combined K/Ka band respectively amplify X and K band signals from separate antennae, and deliver those signals over separate, elongated and narrow signal paths to X/K mixers, where those signals are mixed with local oscillator (LO) signals to produce IF for detection.
Abstract: A radar detector includes features to reduce emissions such as those typically generated by the detector's local oscillator. Two low noise amplifiers (LNA's), operating in X band and a combined K/Ka band, respectively amplify X and K/Ka band signals from separate antennae, and deliver those signals over separate, elongated and narrow signal paths to X and K/Ka mixers, where those signals are mixed with local oscillator (LO) signals to produce IF for detection. The elongated, narrow signal paths from the antennae to the mixers reduce LO emissions, and those emissions are further reduced by incorporating radar absorbers between the circuit board and detector case along the antenna-mixer path, including radar absorptive paint on the circuit board itself along this path, and sealing the case with a conductive sealing gasket.
12 Jun 2005
TL;DR: An integrated planar switched-beam antenna based on rectangular waveguide antenna and Butler matrix network for beamforming, which is implemented by complementary-conducting-strip transmission line (CCS TL), is presented in this article.
Abstract: This paper presents an integrated planar switched-beam antenna based on rectangular waveguide antenna and Butler matrix network for beamforming, which is implemented by complementary-conducting-strip transmission line (CCS TL). The 32-GHz waveguide antenna with size of 71.5 mm by 4.1 mm, consisting of 20 slots in the broadside wall, is built on the Rogers RO4003 (/spl epsiv//sub r/ = 3.38) substrate. For a compact and reliable design of the Butler matrix beamformer, the branch-line coupler and the crossover of the Butler matrix are designed by CCS TLs with characteristic impedance of 60 and 85 /spl Omega/, respectively. The proposed 4-beam smart antenna shows the steered beams in orthogonal direction at 38/spl deg/, 76/spl deg/, 106/spl deg/, and 136/spl deg/, respectively, and demonstrates a great potential for planar integration of smart antenna for wireless communication application. Measured results agree well with theoretical predictions, validating the design concepts employed in the millimeter-wave smart antenna design.
TL;DR: In this article, the authors studied rain attenuation at the Ka-band in northern Taiwan from long-term experimental measurements using a CW system at vertical polarization, optical rain gauge, a...
Abstract: In this paper, we study rain attenuation at Ka-band in northern Taiwan from long-term experimental measurements using a Ka-band (28.35 GHz) CW system at vertical polarization, optical rain gauge, a...
03 Jul 2005
TL;DR: A hard hom for dual band operation is designed, with emphasis has been put on low cross-polar performance over both the Rx and Tx bands in the Ka-band multimedia application.
Abstract: A hard hom for dual band operation is designed. Emphasis has been put on low cross-polar performance over both the Rx and Tx bands in the Ka-band multimedia application. The horn has also been designed with manufacturability in mind, with direct transition from the metal section to the corrugated section, and, with a corrugated section which is slightly conical with constant number of corrugations. The horn operates with high efficiency at the lower band (17.7-20.2 GHz) and medium efficiency at the higher band (27.5-30.0 GHz), and it has a maximum cross-polar level within the main beam which is low over both bands. The return-loss is below -35 dB over both bands.
01 Jan 2005
TL;DR: In this article, two Ka band spatial power amplifiers using MMIC circuits and multilayer technology are presented, which are based on quasioptical or spatial power combining techniques in a rectangular waveguide and according to the tray topology.
Abstract: This paper presents the designs of two Ka band spatial power amplifiers using MMIC circuits and multilayer technology. The design approach is based on quasioptical or spatial power combining techniques in a rectangular waveguide and according to the tray topology. An improved matching waveguide to coplanar transition is presented first with integrated bridges on the coplanar section for even mode cancellation. The transition exhibits very low insertion loss, better than 1 dB over the entire Ka band. The designed spatial amplifiers use two trays with either one MMIC amplifier on each tray (2/spl times/1) or two MMICs (2/spl times/2). The performances of the 2/spl times/1 spatial amplifier are presented showing a gain of 20 dB and a combining efficiency higher than 85% between 31 and 36 GHz. Simulation results of the 2/spl times/2 spatial amplifier are also presented showing a good combining efficiency level.
15 Jun 2005
TL;DR: In this article, the performance of a Ka-band (20/30 GHz) dual circularly polarized feed polarizer designed for reflector antennas for satellite transmit and receive communications is presented.
Abstract: The performance of a Ka-band (20/30 GHz) dual circularly polarized feed polarizer designed for reflector antennas for satellite transmit & receive communications is presented. The arrays of pins have been used as a delay structure to achieve the desired phase shift in both bands.
10 Jun 2005
TL;DR: An experimental polygon, equipped by a complex of polarimetric, combined, short pulse scatterometer-radiometer systems of S-, Ku-, and Ka-band of frequencies, for bare soil, soil vegetation and land snow cover microwave reflective and emissive characteristics simultaneous and spatially coincident measurements.
Abstract: A complex of polarimetric (dual polarization), spatio-temporally combined active-passive devices of S (~3GHz), C (~5.6GHz), Ku (~20GHz), and Ka (~37GHz) band of frequencies is represented, for bare and vegetated soils, waved water surface and land snow cover microwave reflective and emissive characteristics simultaneous, multi-frequency, polarimetric and spatially coincident measurements. The complex is dedicated to solve problems applied to soil (bear and vegetated) and snow moistures retrieval, to near water surface wind and wave field parameters retrieval, by microwave means of remote sensing, as well as applied to surface and sub-surface targets detection and identification tasks solution. The complex is set in ECOSERV ROC's control-test experimental site, in Armenia, which is equipped by facilities for microwave devices absolute calibration, by spatially distributed stations for in-situ measurements of soil
moisture and temperature, and has a local meaning small weather station. This paper has an aim to attract attention of researchers who are interested in such kind measurements and to invite them to perform their own or joint measurements using available facilities.
TL;DR: In this paper, a traveling wave tube-based millimeter-wave amplification module is proposed for millimeter wave fixed wireless access base stations and Ka-band satellite Internet terminals. But the development of a 100-W peak power mmWave power module is not discussed.
Abstract: Various types of millimeter-wave radio systems are being developed for strong broadband service demands such as fixed wireless access, local multipoint distribution service, as well as satellite communications. In each system, the higher data rate transmission requires more powerful amplification devices. This paper describes the development of a Ka-band 100-W peak power millimeter-wave power module, traveling wave tube-based millimeter-wave amplification module, used for millimeter-wave fixed wireless access base stations and Ka-band satellite Internet terminals.