Showing papers on "Ka band published in 2008"
TL;DR: In this paper, a substrate integrated waveguide (SIW) multibeam antenna is proposed for mobile satellite communications using beam switching and diversity techniques, which employs an SIW Rotman lens as the beamforming network.
Abstract: A new type of substrate integrated waveguide (SIW) multibeam antenna is proposed for mobile satellite communications using beam switching and diversity techniques. It employs an SIW Rotman lens as the beamforming network. The prototype of a single multibeam antenna is implemented at 28.5 GHz with seven input ports and an antenna array constructed by nine SIW linear slot arrays, which can generate a corresponding number of beams along one dimension. Several such antennas are grouped in two different ways to cover a 2-D solid angle with multiple beams. Experiment results show that the 2-D solid angle around (-40deg, 40deg) X (-35deg, 35deg) or (-25deg, 25deg) x (-35deg, 35deg) are covered with 20 or 25 beams with 5 -dB beamwidth, respectively. It is demonstrated that this type of printed multibeam antenna is a good choice for communication applications where mobility and high gain are simultaneously required.
202 citations
TL;DR: In this paper, the radiation efficiency of a dielectric resonator antenna (DRA) and a microstrip antenna (MSA) at the Ka band was investigated numerically and experimentally.
Abstract: The radiation efficiency of a dielectric resonator antenna (DRA) and a microstrip antenna (MSA) at Ka band is investigated numerically and experimentally. For direct comparison, one cylindrical DRA and one circular disk MSA were designed with similar feeding networks for operation at around 35 GHz. The efficiency of both devices was measured using the directivity/gain (D/G) method and the Wheeler cap method, in both of which the losses in the test system and the feeding structure were taken into account for calibration purposes. A good agreement between measured and simulated results for both methods is found, when considering the effect of the sampling interval and cross-polarization in the D/G method and the effect of the metallic cap size in the Wheeler cap method. It is finally demonstrated that the radiation efficiency of the DRA is significantly higher than that of the MSA at millimeter wave frequencies.
142 citations
TL;DR: In this paper, a new technique for designing dual-band frequency selective surfaces with arbitrary bands of operation with second-order band-pass responses at each band of operation is presented and experimentally verified.
Abstract: In this letter, a new technique for designing dual-band frequency selective surfaces with arbitrary bands of operation, with second-order band-pass responses at each band of operation, is presented and experimentally verified. The technique is based on utilizing a particular topology of a second-order band-pass microwave filter and synthesizing its constituting elements using periodic structures with inductive, capacitive, or resonant type surface impedances. The result is a low-profile planar structure composed of three metal and two dielectric layers that acts as a spatial version of the dual-band microwave filter.
122 citations
TL;DR: In this paper, a low-loss waveguide combining and a packaged monolithic microwave integrated circuit with a low loss microstrip-to-waveguide launcher is developed into a high power -band (31-36 GHz) amplifier producing 50 W at 33 GHz (Ka-band) using 32 low-power (>2 W) solid-state amplifier modules.
Abstract: A method of using low-loss waveguide septum combiners is developed into a high-power -band (31-36 GHz) amplifier producing 50 W at 33 GHz (Ka-band) using 32 low-power (>2 W) solid-state amplifier modules. By using low-loss waveguide combining and a packaged monolithic microwave integrated circuit with a low-loss microstrip-to-waveguide launcher, the output loss is minimized, allowing for the overall power-combining efficiency to remain high, 80% (average insertion loss of combiner < 0.7 dB and average insertion loss of launcher <0.3 dB) over 31-36 GHz. In the past, lower power-combining efficiencies have limited the number of modules that can be combined at -band, and hence, have limited the power output. The approach demonstrated in this paper, with high power-combining efficiency, allows a very large number (32) of solid-state amplifier modules to be combined to produce high powers. Greater than 50 W was demonstrated with low power modules, but even higher powers 120 W are possible. The current approach is based on corporate combining, using low-loss waveguide septum combiners that provide isolation, maintaining the true graceful degradation of a modular solid-state amplifier system.
95 citations
TL;DR: In this article, two new compact lens antenna configurations are presented and compared for data link communications with LEO satellites at 26 GHz, and two alternative lens configurations are evaluated numerically and experimentally: one is based on modified axial-symmetric dome lens geometry, and the other one consists of a full 3-D double-shell lens antenna.
Abstract: Two new compact lens antenna configurations are presented and compared for data link communications with LEO satellites at 26 GHz These lenses match a secant type radiation pattern template in the elevation plane while having a mechanically scanned sector beam in azimuth to enhance gain as much as possible No rotary joints or multiple feeds are required and emphasis is put also on the compactness of the proposed solutions (< 6lambda0) Two alternative lens configurations are evaluated numerically and experimentally: one is based on modified axial-symmetric dome lens geometry, and the other one consists of a full 3-D double-shell lens antenna In contrast to current nearly omnidirectional antennas, the directivity of our lens prototypes is above 154 dBi Up to 42 dB loss obtained in the prototypes can be significantly reduced by using lower loss dielectrics and matching layers, without affecting the conclusions The numerical and experimental results are in good agreement with the radiation specifications given the compact size of the antennas
94 citations
TL;DR: In this article, a new Ka-band ground-based noise waveform synthetic aperture radar (GB NW-SAR) is proposed for remote monitoring of various manmade or natural objects, such as ceilings and roofs of big halls and hangars, dams, bridges, TV towers etc.
Abstract: The designing and testing of a new Ka-band ground-based noise waveform synthetic aperture radar (GB NW-SAR) are presented. Its design is based upon new synthetic aperture antennas and noise radar technology. The authors present preliminary results of its indoor trials. The GB NW-SAR designed may be reconfigured for operation in mono-, bi- and multistatic (or MIMO) modes in both CW and pulse regimes using single- and dual-frequency modes to enhance range resolution via expanding the frequency bandwidth of the signal. Potential resolution of the GB NW-SAR is 15 cm both in range and azimuth. Results of indoor trials are presented for both SAR imaging and differential interferometry measurements. Designed and tested Ka-band GB NW-SAR is applicable for precise remote monitoring of various manmade or natural objects, such as ceilings and roofs of big halls and hangars, dams, bridges, TV towers etc.
64 citations
TL;DR: In this article, a low-loss planar spatial power-combining architecture based on half model substrate integrated waveguide (HMSIW) is proposed and studied, which is realized by transition between a HMSIW and parallel multiport planar microstrip lines.
Abstract: In this letter, a simple low-loss planar spatial power-combining architecture based on half model substrate integrated waveguide (HMSIW) is proposed and studied. The power-combining structure is realized by transition between a HMSIW and parallel multiport planar microstrip lines. The power combiner is simulated and measured at 34.5-36.5 GHz. Measured results show a good agreement with simulation and a combining efficiency of 82% is achieved at 35 GHz.
54 citations
15 Jun 2008
TL;DR: In this paper, a 10-dB and 20-dB directional coupler is designed and fabricated using air-core rectangular coaxial transmission lines, and the couplers are both smaller than 1.8 by 4.2mm2 with probing points.
Abstract: 2.5-dimensional, 10-dB and 20-dB directional couplers, are designed and fabricated using air-core rectangular coaxial transmission lines. The couplers are both smaller than 1.8 by 4.2mm2 with probing points. The measured performance of the coupler is in agreement with full-wave simulations. The components are designed such that probing or flip-chip attachment can be done with the same structures. A flip-chip transition from rectangular coax to traditional co-planar waveguide is also presented.
45 citations
TL;DR: Based on the substrate integrated waveguide (SIW) technology, a new type of Ka-band Gunn diode Oscillator was developed in this paper, which has some advantages such as planar integration, low cost, small size, good temperature-frequency stability, low phase noise.
Abstract: Based on the substrate integrated waveguide (SIW) technology, a new type of Ka-band Gunn Diode Oscillator was developed. Main emphasis was placed on SIW resonant cavity structure. Restrictions on the performance of the oscillators imposed by packaged networks and the self-characteristic of the Gunn diode devices have been analyzed. This oscillator performance is characterized by a medium level output power of 15.2 dBm, a low phase noise less than -91.23 dBc/Hz at 100 kHz and frequency excursion 53 MHz over temperature range from 15degC to 70degC. It has some advantages such as planar integration, low cost, small size, good temperature-frequency stability, low phase noise.
38 citations
TL;DR: In this article, a 2-bit Ka-band RF MEMS frequency tunable slot antenna is demonstrated on a fused silica wafer using a micro-fabrication process requiring six masks.
Abstract: A 2-bit Ka-band RF MEMS frequency tunable slot antenna is disclosed. It is demonstrated on a fused silica wafer using a micro-fabrication process requiring six masks. The return loss and gain for each of the four states are measured using a probe station based setup for on-wafer antenna measurements. The antenna has a measured tunable bandwidth of 6.8 GHz. The average measured gain is 1.74 dBi, and the average measured cross-polarization is -9.22 dBi. The extracted switching time is 5.19 mus for a drive voltage of 45 V.
35 citations
Netherlands Institute for Space Research1, Leiden University2, Centre national de la recherche scientifique3, California Institute of Technology4, University of Cologne5, ETH Zurich6, Chalmers University of Technology7, Max Planck Society8, INAF9, University of Waterloo10, Jet Propulsion Laboratory11, Delft University of Technology12, Netherlands Organisation for Applied Scientific Research13, National University of Ireland14, Spanish National Research Council15, University of Leicester16, École Normale Supérieure17
TL;DR: The Heterodyne Instrument for the Far-Infrared (HIFI) as discussed by the authors was designed to be electronically tuneable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 km/s.
Abstract: This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI), to be launched onboard of ESA's Herschel Space Observatory, by 2008. It includes the first results from the instrument level tests. The instrument is designed to be electronically tuneable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 km/s with a high sensitivity. This will enable detailed investigations of a wide variety of astronomical sources, ranging from solar system objects, star formation regions to nuclei of galaxies. The instrument comprises 5 frequency bands covering 480-1150 GHz with SIS mixers and a sixth dual frequency band, for the 1410-1910 GHz range, with Hot Electron Bolometer Mixers (HEB). The Local Oscillator (LO) subsystem consists of a dedicated Ka-band synthesizer followed by 7 times 2 chains of frequency multipliers, 2 chains for each frequency band. A pair of Auto-Correlators and a pair of Acousto-Optic spectrometers process the two IF signals from the dual-polarization front-ends to provide instantaneous frequency coverage of 4 GHz, with a set of resolutions (140 kHz to 1 MHz), better than < 0.1 km/s. After a successful qualification program, the flight instrument was delivered and entered the testing phase at satellite level. We will also report on the pre-flight test and calibration results together with the expected in-flight performance.
01 Oct 2008
TL;DR: In this article, the authors presented two 3-pole tunable bandpass coplanar filters that include BST ferroelectric capacitors, tunable from 28 GHz up to 37 GHz.
Abstract: This paper presents two 3-pole tunable bandpass coplanar filters that include BST ferroelectric capacitors, tunable from 28 GHz up to 37 GHz. Both filters consist of cascaded coplanar transmission resonators, loaded with high-quality factor discrete BST capacitors. The first design includes 6 capacitors and the second one is loaded with 12 capacitors. The capacitance is varied from 60 fF up to 20 fF. A first fabrication was done only with fixed capacitances, in order to validate the model. The insertion loss was around 5 dB at 30 GHz.
Journal Article•
TL;DR: Simulation results show that the proposed passer assignment mechanism in Ka-band orthogonal frequency division multiplexing (OFOM)-based multi-satellite mobile telemedicine can not only fulfill the quality of services (QoS), but can also achieve maximum transmission bit rates as well as minimum transmission power.
Abstract: In this paper, we propose a passer assignment mechanism in Ka-band orthogonal frequency division multiplexing (OFOM)-based multi-satellite mobile telemedicine. The mobile telemedicine system considers the employment of FODM techniques, multi-satellite transmission architectures, space time block code (STBC) strategies, direct nap (DM) strategies, power assignment mechanisms, unequal error protection mechanism, channel estimation, and adaptive modulation schemes in a Ka band. Simulation results show that the proposed scheme can not only fulfill the quality of services (QoS) required by a nubile telemedicine system, but can also achieve maximum transmission bit rates as well as minimum transmission power.
05 Nov 2008
TL;DR: An experimental radar has been designed and built using the most advanced solid state technology available in this frequency region and results achieved with this instrument are described.
Abstract: Millimeterwave radars at Ka- and W-band are state of the art and are used as well for civilian as military applications. The higher atmospheric windows, 140 GHz and 220 GHz, are not widely used to date. With the advance of automotive and security applications requiring short and medium range radars, these frequency bands become an interesting alternative. At the same time technology to expand radar use to the upper millimeterwave bands becomes available. An experimental radar has been designed and built using the most advanced solid state technology available in this frequency region. The paper describes the radar set-up at 220 GHz and gives results achieved with this instrument.
11 May 2008
TL;DR: By using the analysis results of the separation distance between the satellite earth station and a terrestrial station with random height, the design and implement Ka band wireless systems with the optimum separation distances can be designed and implemented, and this will lead efficient use of limited frequency spectrum resources.
Abstract: Co-existence of various wireless systems may cause frequency interference problems. For this reason, frequency sharing studies play a very important role in order to use limited spectrum resources efficiently. Because a satellite system covers a global area in nature, the frequency sharing between the satellite and terrestrial systems is essential. For satellite systems using Ka bands, we can increase spectrum efficiency by considering off- axis angles of the earth station antennas. In this paper, we demonstrate the analysis results of the separation distance between the satellite earth station and a terrestrial station with random height. By using these results, we can design and implement Ka band wireless systems with the optimum separation distances, and this will lead efficient use of limited frequency spectrum resources.
15 Jun 2008
TL;DR: In this article, the design, implementation, and test of a compact antenna array providing polarization multiplexing at 30 GHz is presented, where the array elements are realized as open-ended substrate-integrated waveguides (SIW).
Abstract: This paper presents the design, implementation, and test of a compact antenna array providing polarization multiplexing at 30 GHz. The array elements are realized as open-ended substrate-integrated waveguides (SIW). Focus of this paper is on the far field analysis of the array for different steering angles and polarizations. Simulation as well as measurement data is presented and discussed.
01 Dec 2008
TL;DR: In this paper, the authors describe a Ka band satellite beacon receiver/radometer for measuring both the sky noise and the attenuation caused by rain and water vapor to satellite signals, at the same frequency and look angle.
Abstract: This paper describes a Ka band satellite beacon receiver / radiometer for measuring both the sky noise and the attenuation caused by rain and water vapor to satellite signals, at the same frequency and look angle. To enable the receiver to stay locked to satellite beacon signals with received power levels between -110 dBm and -170 dBm, a receiver with an ultra low phase noise, an absence of spurious signals and using advanced digital signal processing (DSP) techniques is required. To obtain rain fade statistics, the received signal power of a satellite beacon is recorded continuously at an eight times per second rate.
21 Apr 2008
TL;DR: In this paper, a power-amplifier (PA) module at the ka-band was presented using a new type of broad-band spatial power-combining system, which can accommodate more monolithic microwave integrated-circuit (MMIC) PA on limited microstrip space in a slotline-to-microstrip transition structure.
Abstract: In this paper, a power-amplifier (PA) module at ka-band presented using a new type of broad-band spatial power-combining system. The combiner can accommodate more monolithic microwave integrated-circuit (MMIC) PA on limited microstrip space in ka-band waveguide structure with good return losses, and heat can dissipated into aluminum carrier quickly. This combiner is based on a slotline-to-microstrip transition structure, which also serves as a four-way power combiner. The proposed 2 times 2 combining structure combined by vertical stacking inside the waveguide was analyzed and optimized by finite-element-method (FEM) simulations and experiments. This paper demonstrates the potential of the proposed power combiner for more MMIC(PA) accepted in this type of high-power amplification at millimeter wave frequencies.
01 Nov 2008
TL;DR: In this article, a modified antenna feed system for simultaneous X/Ka-band satellite ground terminals is presented, which retains the important functionality of the existing feed system, using a simplified approach that aims to reduce the weight and the cost of manufacture.
Abstract: A variation on an existing antenna feed system for use on simultaneous X/Ka-band satellite ground terminals is presented. The modified design retains the important functionality of the existing feed system, using a simplified approach that aims to significantly reduce the weight and the cost of manufacture.
15 Jun 2008
TL;DR: In this paper, a 1×N (with arbitrary N) power divider based on multimode interference imaging in substrate integrated waveguide (SIW) technology is proposed, which is demonstrated by fully-wave analysis and experimental results in the case of a division ratio of 1/6.
Abstract: A 1×N (with arbitrary N) power divider based on multimode interference imaging in substrate integrated waveguide (SIW) technology is proposed. This divider is demonstrated by fully-wave analysis and experimental results in the case of a division ratio of 1/6. It is implemented at Ka band with the use of continuous wall SIW geometry. The insertion loss from the input to each output of the divider at 25 GHz is −9 dB. Compared with traditional corporate dividing structures, this divider has a much simpler configuration and also a lower design complexity. This device may find applications in the design of millimeter-wave and quasi-optical spatial power combiners, antenna feeding networks and amplifiers.
01 Nov 2008
TL;DR: In this paper, a Ka band Cassegrain monopulse antenna has been designed and measured, and the measurements show that the gain of sum pattern is 28 dBi, the sidelobe levels of the sum pattern are less -15 dB, the null depths of the difference pattern were less then -25 dB and the bandwidth of VSWRz<2 is more than 6.5 GHz.
Abstract: A Ka band Cassegrain monopulse antenna has been designed and measured. The tapered rod antennas are used as the feeds of the Cassegrain antenna because their blockage is small and their bandwidths are very wide. The measurements show that the gain of sum pattern is 28 dBi, the sidelobe levels of the sum pattern are less -15 dB, the null depths of the difference pattern are less then -25 dB and the bandwidth of VSWRz<2 is more than 6.5 GHz.
TL;DR: In this paper, a compact Ka-band doubly balanced diode mixer with new phase relationships is demonstrated. But this mixer has a conversion loss between 9 to 12 dB, a dc-3.5 GHz IF bandwidth, and a good port-to-port isolation in Ka band.
Abstract: A compact Ka-band doubly balanced diode mixer with new phase relationships is demonstrated. In this design, a novel configuration was employed to have good performance while keeping compact size and simple intermediate frequency (IF) extraction. It is flexible not only in layout design, but also in the reduction of IF inductance. The chip dimension is as small as 0.851.35 mm, implemented by using a 0.15 m PHEMT technology. This mixer has a conversion loss between 9 to 12 dB, a dc-3.5 GHz IF bandwidth, and a good port-to-port isolation in Ka band.
Patent•
15 Jul 2008TL;DR: In this paper, a self-contained module that contains a radio frequency (RF) channel at a fundamental frequency is described, where a phase lock oscillator drives an RF signal path in the RF channel.
Abstract: A Ka-band transmitter. The transmitter is in a self-contained module that contains a radio frequency (RF) channel. A phase lock oscillator drives an RF signal path in the RF channel at a fundamental frequency. In-phase data (I-data) and Quadrature data (Q-data) difference signals are converted to single ended signals and filtered in a pair of low pass filters and passed as inputs to a Quadriphase Shift Keying (QPSK) vector modulator in the RF signal path, e.g., an in-line even-harmonic modulator. The output of the QPSK vector modulator, is a Ka-band signal that is passed to a driver which may drive a load, e.g., an antenna.
01 Jan 2008
TL;DR: In this article, the efficiency of linearization for pre-distortion in 64-QAM modulation, utilized in Ka-band satellite link for DVB-RCS services, is investigated.
Abstract: Summary In this paper the efficiency of linearization for pre-distortion in 64-QAM modulation, utilized in Ka-band satellite link for DVB-RCS services, is investigated. The linearization is simulated by Matlab-Simulink, for a GEO Satellite and DVBRCS service. A TWTA power amplifier with 1dB back-off is used in this satellite link, and to conclude the results, the spectrum and eye-diagram in both transmitter and receiver side are evaluated.
01 Oct 2008
TL;DR: In this article, a novel concept of integrated antenna feed in the Ka band has been developed, which enables the integration of active elements very close to the radiating surface, which reduces dramatically the weight and volume of the antenna.
Abstract: Thanks to Vertical Multi-Chip Module packaging technology (MCM-V), a novel concept of integrated antenna feed in Ka band has been developed. This technology enables the integration of active elements very close to the radiating surface, which reduces dramatically the weight and volume of the antenna. In this paper the different technological building blocks are described, and the measurements obtained on the first breadboard are discussed. The promising results obtained should lead to a major breakthrough for active receive antennas, driving down cost and complexity.
17 Nov 2008
TL;DR: The design of a digital signal processing (DSP) based JCU-STRAP (James Cook University - Satellite Transmission Rain Attenuation Project) Ka band satellite beacon receiver / radiometer for measuring both the sky noise and the attenuation caused by rain and water vapour to satellite signals, at the same frequency and look angle is described.
Abstract: This paper describes the design of a digital signal processing (DSP) based JCU-STRAP (James Cook University - Satellite Transmission Rain Attenuation Project) Ka band satellite beacon receiver / radiometer for measuring both the sky noise and the attenuation caused by rain and water vapour to satellite signals, at the same frequency and look angle. To obtain rain fade statistics, the received signal amplitude of a satellite beacon is recorded at an eight times per second rate. To maximise the dynamic range over which the receiver can stay locked onto the satellite beacon, a receiver with an ultra low phase noise and absence of spurious signals is required.
TL;DR: In this paper, a broadband doubly balanced monolithic ring mixer with a new intermediate frequency (IF) signal extraction method implemented by 0.15 mum pHEMT process is presented.
Abstract: A broadband doubly balanced monolithic ring mixer with a new intermediate frequency (IF) signal extraction method implemented by 0.15 mum pHEMT process is presented. The hybrid couplers of the proposed mixer consist of multiple coupled lines and fourfold coupled line Marchand baluns. The use of multiple coupled lines leads to a die size less than 1 times 1 mm2 and improves the bandwidth of the mixer. The novel fourfold coupled line allows the extraction of the IF signal directly without any extra low pass filter circuits. The mixer exhibited 8-13 dB conversion loss, high radio frequency/local oscillation isolation of 35-50 dB over 16-40 GHz and an input 1-dB compression point of 14 dBm.
27 May 2008
TL;DR: In this paper, a quasi-stationary mode of operation of a high-efficiency 38 GHz relativistic microwave backward-wave oscillator at a pulse repetition rate of 10 Hz has been demonstrated.
Abstract: The quasi-stationary mode of operation of a high-efficiency 38-GHz nanosecond relativistic microwave backward-wave oscillator at a pulse repetition rate of 10 Hz has been demonstrated. A hybrid modulator based on an SM-3N SOS driver and on an energy compression unit containing a pulse-forming line and a spark gap was used to produce 5-ns electron-beam-accelerating pulses of the trapezoidal shape. Optimization of the energy exchange between the weakly magnetized electron flow and the oncoming harmonics of the TM01 wave inside the periodic slow-wave structure has made it possible to achieve a peak power of ~170 MW for 4-ns microwave pulses at an electron efficiency no less than 30-35%.
01 Dec 2008
TL;DR: In this paper, a 1 times 8 monopulse microstrip patch antenna array in Ka-band has been proposed, where the radiating element is a modified circular patch antenna, designed for getting circular polarization.
Abstract: A 1 times 8 monopulse microstrip patch antenna array in Ka-band has been proposed The radiating element is a modified circular patch antenna, designed for getting circular polarization The feed network is composed of six Wilkinson power dividers, a 3 dB hybrid, and a microstrip to waveguide transition Both the array and the feed network are placed on the same layer
22 Apr 2008
TL;DR: In this article, a Ka-band high power traveling-wave tube with folded waveguide as its slow wave structure was designed and the simulation result show it can output 1000 Watte and the bandwidth is more than 1 GHz.
Abstract: A Ka-band High Power Traveling-Wave Tube was designed with folded waveguide as its slow wave structure. The simulation result show it can output 1000 Watte and the bandwidth is more than 1 GHz. It maybe an ideal driving source for Gyroklystrons and Gyro-TWT.