Showing papers on "Ka band published in 2009"

Land surface temperature from Ka band (37 GHz) passive microwave observations

Abstract: [1] An alternative to thermal infrared satellite sensors for measuring land surface temperature (Ts) is presented. The 37 GHz vertical polarized brightness temperature is used to derive Ts because it is considered the most appropriate microwave frequency for temperature retrieval. This channel balances a reduced sensitivity to soil surface characteristics with a relatively high atmospheric transmissivity. It is shown that with a simple linear relationship, accurate values for Ts can be obtained from this frequency, with a theoretical bias of within 1 K for 70% of vegetated land areas of the globe. Barren, sparsely vegetated, and open shrublands cannot be accurately described with this single channel approach because variable surface conditions become important. The precision of the retrieved land surface temperature is expected to be better than 2.5 K for forests and 3.5 K for low vegetation. This method can be used to complement existing infrared derived temperature products, especially during clouded conditions. With several microwave radiometers currently in orbit, this method can be used to observe the diurnal temperature cycles with surprising accuracy.

Single and Four-Element $Ka$ -Band Transmit/Receive Phased-Array Silicon RFICs With 5-bit Amplitude and Phase Control

Abstract: Ka-band SiGe BiCMOS single- and four-element phased arrays capable of both transmit and receive operation with 5-bit phase and amplitude control are presented. The design is based on the All-RF architecture with RF phase shifters and attenuators, and a 4:1 passive power combining/dividing network. The four-element array results in an average gain of ~ 0 dB per channel and a noise figure of 9.0 dB, and is designed to be placed behind III-V T/R modules. The rms phase error is 5.6° (5-bit operation) and < 12.5° (4-bit operation) over a 2 or 5 GHz instantaneous bandwidth, respectively, centered at around 36.5 GHz. In the receive mode, the input P1dB is -16 dBm per channel (IIP3 of - 5.9 dBm), and in the transmit mode, the output P1dB is +4-5 dBm, all at 35-36 GHz. The measured isolation between the channels is better than 30 dB. The array maintained excellent phase characteristics up to 100°C with no change in the rms phase error. Also, ten different four-element phased arrays were tested (40 channels) and result in an rms gain variation of 0.5 dB at 34-39 GHz. The four-element array consumes 171 and 142 mW in the Tx and Rx modes from 1.8 V, and occupies an area of 2.0 × 2.02 mm2. To our knowledge, this is the smallest and lowest power consumption on-chip K ?-band phased-array to-date.

Robust AlGaN/GaN Low Noise Amplifier MMICs for C-, Ku- and Ka-Band Space Applications

Abstract: The high power capabilities in combination with the low noise performance of Gallium Nitride (GaN) makes this technology an excellent choice for robust receivers. This paper presents the design and measured results of three different LNAs, which operate in C-, Ku-, and Ka-band. The designs are realized in 0.25 μm and 0.15 μm AlGaN/GaN microstrip technology. The measured noise figure is 1.2, 1.9 and 4.0 dB for the C-, Ku-, and Ka-frequency band respectively. The robustness of the LNAs have been tested by applying CW source power levels of 42 dBm, 42 dBm and 28 dBm for the C-band, Ku-band and Ka-band LNA respectively. No degradation in performance has been observed.

Design, Analysis, and Development of a Large Ka-Band Slot Array for Digital Beam-Forming Application

Abstract: This paper discusses the design, analysis, and development of a large Ka-band slot array for digital beam-forming application. The array consists of 160 times 160 elements in 16 subarrays for producing 16 digital beams in the receive mode. Infinite array mutual coupling model has been employed in the design and analysis models. Challenges posed in meeting the pattern and return loss specifications because of manufacturing tolerances are discussed. Measured return loss and pattern characteristics of 10 times 40 slot array modules as well as results on a 1 m times 1 m demonstration array are presented.

SANTANA: Advanced electronically steerable antennas at Ka-Band

Abstract: This paper presents the background, the vision, and the motivation of the SANTANA project (Smart Antenna Terminal). Recent realizations of electronically steerable receive (Rx) and transmit (Tx) antennas for satellite communications at Ka-Band are shown. In detail, the integration and packaging techniques of frontend modules, which combine the antenna, the RF circuitry, and the cooling system within one functional block, are discussed. In addition, a novel digital beam steering concept as well as a hybrid beam steering approach are addressed. It will be shown that these system concepts can be applied to large antenna arrays as needed to fulfill link budget requirements for the intended satellite communications.

Ultra-High Power and Efficiency Space Traveling-Wave Tube Amplifier Power Combiner With Reduced Size and Mass for NASA Missions

Abstract: In the 2008 IEEE Microwave Theory and Techniques Society International Microwave Symposium Digest version of our paper, recent advances in high power and efficiency space traveling-wave tube amplifiers for NASA's space-to-Earth communications are presented. The RF power and efficiency of a new K-band amplifier are 40 W and 50% and that of a new K-band amplifier are 200 W and 60%. An important figure-of-merit, which is defined as the ratio of the RF power output to the mass (W/kg) of a traveling-wave tube (TWT), has improved by a factor of 10 over the previous generation Ka-band devices. In this paper, a high power high efficiency Ka -band combiner for multiple TWTs, based on a novel hybrid magic-T waveguide circuit design, is presented. The measured combiner efficiency is as high as 90%. In addition, at the design frequency of 32.05 GHz, error-free uncoded binary phase-shift keying/quadrature phase-shift keying (QPSK) data transmission at 8 Mb/s, which is typical for deep-space communications, is demonstrated. Furthermore, QPSK data transmission at 622 Mb/s is demonstrated with a low bit error rate of 2.4 times10-8, which exceeds the deep-space state-of-the-art data rate transmission capability by more than two orders of magnitude. A potential application of the TWT combiner is in deep-space communication systems for planetary exploration requiring transmitter power on the order of a kilowatt or higher.

A study of the thin film bulk acoustic resonator filters in several ten GHz band

Abstract: The first K to Ka band filters using thin film bulk acoustic resonators (FBARs) have been developed. The filters are ladder type filters configured with air-gap type FBARs and designed using an equivalent circuit based on a Butterworth-Van-Dyke (BVD) model. Center frequency, fractional bandwidth, minimum insertion loss and suppression in out-band were 23.8 GHz, 3.4%, −3.8 dB and −13 dB in the K band filter, and were 29.2 GHz, 3.4%, −3.8 dB and −11 dB in the Ka band filter, respectively. 24.7 GHz in resonant frequency, 285 in resonant Q, 291 in anti-resonant Q and 6.0% in effective electro-mechanical coupling coefficient k eff 2 were obtained in the K band FBAR. Additionally, it was derived and verified experimentally that the loss is proportional to the product of the resonant frequency and the capacitance ratio in the FBAR. This relation allowed the limitation of the FBAR filter to be discussed for higher frequencies.

Multi-Feed Antenna System for Satellite Communicatons

Abstract: The present invention provides an improved single antenna system that allows reception of RF energy at multiple frequencies. In one embodiment, the antenna is implemented as a multi-beam, multi-feed antenna having a primary reflector fitted with a dual mode feed tube and a switchable LNB that supports both Ka band and Ku band reception. In another embodiment, the antenna is implemented as a multi-beam, multi-feed antenna having a primary reflector fitted with a feed horn and a LNB that is capable of providing movement such that the feed horn with the LNB is at a focal point with the primary reflector for both Ka and Ku band reception. In another embodiment, the antennae is implemented as a multi-beam, multi-feed antenna having a primary reflected fitted with a feed horn assembly and a switchable LNB that supports both Ka band and Ku band reception.

$Ka/Ku$ -Band pHEMT Gilbert Mixers With Polyphase and Coupled-Line Quadrature Generators

Abstract: In this paper, three kinds of Kalpha/Ku-band Gilbert mixers are demonstrated using 0.15- mum AlGaAs/InGaAs pseudomorphic high electron mobility transistor technology. Thanks to the semiinsulating GaAs substrate, microwave passive components have a low-loss feature, and polyphase filters work up to higher frequencies. Highly accurate tantalum-nitride thin-film resistors utilized in polyphase filters result in perfect quadrature operation. Therefore, our proposed single-sideband up-converter operates at 15 GHz with a 63-dB sideband rejection ratio, and another 34-GHz in-phase/quadrature (I/Q) subharmonic down-converter reaches <0.4-dB magnitude and < 1deg phase errors. More than 50-dB local oscillator (LO) leakage suppression is achieved in the I/Q subharmonic mixer. On the other hand, a 40-GHz stacked-LO subharmonic mixer with a novel compensation technique is also proposed and demonstrated to improve LO speed and reduce the amount of transistors, as compared to previous work.

Improvement of open resonator technique for dielectric measurement at millimetre wavelengths

Abstract: An open resonator system is designed and constructed for the accurate measurement of complex permittivity at Ka band It is solved successfully for the first time in how to achieve the consistency of cavity lengths corresponding to different resonant frequencies over a broad band and how to determine the proper permittivity from multiple transcendental equation roots of one sample Many kinds of samples such as fused quartz, Teflon, quartz ceramic, MgF 2 and MgAl 2 O 4 are measured and the results are in good agreement with published data The systematic error analysis shows that the relative standard deviation of the measurement system is less than 0172% for permittivity and 1835% for loss tangent The software developed to control the system improves the measurement efficiency greatly

Development of High-Power Ka/Q Dual-Band and Communications/Radar Dual-Function Helix-TWT

Abstract: Future military communication systems on mobile satellite uplink platforms such as ground-based high-mobility vehicles and unmanned aerial vehicles (UAVs) and aircraft have strict constraints in size, weight, and power. Despite these constraints, these platforms also require ever-increasing data rate and bandwidth for video/imagery transmissions from small aperture terminals. In addition to the communications requirements, more UAV platforms, as an important part of current and future military operations, desire radar capabilities for ground mapping and visibility through poor weather conditions. In 2007, as part of an ongoing effort to meet these demands, L-3 Communications Electron Technologies, Inc. successfully developed a Ka/Q dual-band helix-traveling-wave tube, i.e., the 8923H, that produces 315 W minimum output power at Ka-band (30-31 GHz) and 200 W minimum output power at Q-band (43.5-45.5 GHz). The device was primarily developed to satisfy the Ka/Q dual-band communications requirements with power goals of 300 W minimum at Ka-band and 175 W at Q-band, but in addition, the device can also dual-function as a radar source in the Ka-radar-band (33-36 GHz) with peak power up to 400 W and duty demonstrated up to 50%, all from a single device.

An optimum design of deep‐space downlinks affected by tropospheric attenuation

Abstract: In the paper, we propose an optimum design of deep-space downlinks made with 2 hops, at Ka band and above, in which each hop should be designed for providing half of the total noise-to-signal power ratio. We have derived this result from maximizing the ratio between the tropospheric attenuation in the 2-hop downlink and that in the 1-hop downlink. The design of the 1st hop (free-space) of the 2-hop downlink can reduce the spacecraft power, for the same antennas physical size, by increasing the carrier frequency from Ka band (32 GHz) to W band (80 GHz). This choice is not available in 1-hop downlink design because of the huge Earth tropospheric attenuation expected in the W frequency band. To show a practical design, we have applied the theory to compare 1-hop downlink design at 32 GHz to 2-hop downlink design that adopts 32 or 80 GHz in the 1st hop. The calculations refer to spacecrafts located at two astronomical units (300×106 km, about planet Mars) and to NASA and ESA receiving stations located in Goldstone (California), Cebreros (Madrid, Spain), Canberra and New Norcia (Australia). At 0.1% outage probability, in an average year or in the worst month, 1-hop downlinks show performance critical or close to fail, because of the large tropospheric attenuation (except at Goldstone), while 2-hop downlinks always work. Copyright © 2009 John Wiley & Sons, Ltd.

Low-cost implementation of broadband microwave receivers in Ka-band using multiport structures

Abstract: The authors introduce a new class of the microwave and millimeter wave multiport receivers These receivers are designed based on a new five-port structure and offer a wide bandwidth The low-cost implementation is the other advantage of this structure The numerical and microwave simulations have been conducted to investigate the characteristics of the receiver In addition, the new five-port receiver has been constructed and measured The analytical and measurement results are in good agreement with each other This indicates that the structure can effectively be used as a high-performance and low-cost wideband receiver for broadband applications As a practical application, the European and North-American local multipoint distribution services band can be covered using this new architecture

Comparison between conventional lenses and an electrically thin lens made using a phase shifting surface (PSS) at Ka Band

Abstract: This paper compares the performance of a thin lens based on a new phase shifting surface (PSS) concept to three conventional lenses at Ka-Band. The pros and cons of each lens antenna are highlighted and verified by experimental results. It is shown that a 90° phase-correcting PSS lens antenna can achieve almost the same gain as the corresponding dielectric plano-hyperbolic lens antenna within a specific operating band along with significant improvements in weight, thickness and cost.

Reconfigurable ka-band switch matrix for on-orbit verification

Abstract: We have developed a fully operational remotely controlled reconfigurable microwave switch matrix for applications in upcoming satellite-based multimedia communication systems. The robust and compact modular setup includes appropriate microwave oscillators, power detectors, and diode drivers. The individual modules take full advantage of the low temperature co-fired ceramics technology (LTCC). The experiment will be controlled by a field-programmable gate array (FPGA), to verify, control, and monitor the operation of the switch matrix during an on-orbit verification in a one-year-period following the expected launch in 2010. Present activities aim at a complete space qualification and the timely integration into the payload of the satellite. The switch matrix is laid out for Ka-band frequencies using a single-pole multiple-throw architecture and incorporates integrated PIN-diode switch circuits. We have achieved very promising values for input matching, insertion loss, and path isolation over the entire passband width of 5GHz, which meet realistic specifications. The electrical control of the switch matrix module is realized by the use of diode drivers, which enable a fully digital control of the path configuration.

Highly integrated KA-Band Tx frontend module including 8×8 antenna array

Abstract: This paper presents the concept and design of a highly integrated KA-band frontend module. In detail, the integration and packaging techniques, which combine the antenna, the RF circuitry and the cooling system within one functional block are discussed. It will be shown that these system concepts can be applied for large antenna arrays as needed to fulfil link budget requirements for the intended satellite communication.

EBG Focal Feed Improvements for Ka-Band Multibeam Space Applications

Abstract: This letter presents the enhancement of an electromagnetic band-gap (EBG) antenna that is used to feed a reflector antenna for a space multibeam application in Ka band. One of the main difficulties in a typical focal feed cluster design is to obtain high illumination performances with neighbored and close radiating elements. The new structure presented in this letter tackles this difficulty by using a two-level EBG antenna as a multibeam focal feed. This last one is designed to illuminate a side-fed offset cassegrain antenna (SFOCA) working in Ka band and dedicated to a multibeam telecommunication coverage over Europe. A prototype has been measured, and the reflector antenna performances have been evaluated in order to show the good results obtained with this new multibeam focal feed.

Highly Integrated Ka-Band Sub-Harmonic Image-Reject Down-Converter MMIC

Abstract: An integrated compact down-converter monolithic microwave integrated circuit chip is presented. It is designed using anti-parallel diode pair sub-harmonic image reject mixer and RF low noise amplifier. The quasi-lumped circuit components are employed in circuit design for the compact chip size. The conversion gain of the chip is 10-14 dB, image rejection above 20 dBc, and noise figure of 3.5-4.5 dB for the RF frequency of 29-36 GHz. The chip size is as compact as 2.24 mm2 on a 100 mum GaAs substrate thickness.

Three-dimensional simulation of a Ka-band relativistic Cherenkov source with metal photonic-band-gap structures

Abstract: This paper presents a three-dimensional particle-in-cell (PIC) simulation of a Ka-band relativistic Cherenkov source with a slow wave structure (SWS) consisting of metal photonic band gap (PBG) structures. In the simulation, a perfect match layer boundary is employed to absorb passing band modes supported by the PBG lattice with an artificial metal boundary. The simulated axial field distributions in the cross section and surface of the SWS demonstrate that the device operates in the vicinity of the π point of a TM01-like mode. The Fourier transformation spectra of the axial fields as functions of time and space show that only a single frequency appears at 36.27 GHz, which is in good agreement with that of the intersection of the dispersion curve with the slow space charge wave generated on the beam. The simulation results demonstrate that the SWS has good mode selectivity.

Facility comparison and evaluation using dual ridge horns

Abstract: In the frame of the activity “Antenna Measurement Techniques and Facility Sharing” of the EU network ACE “Antenna Centre of Excellence” [1] substantial attention has been devoted to perform a series of antenna measurement facility comparisons. The activities have been performed using SATIMO dual ridge horns in L, S and C band (SH800) and in Ku and Ka band (SH2000) [2–5]. This paper discuss the activities and preliminary results of the comparison campaign in Ku and Ka band using the SATIMO dual ridge 2–32GHz horn (SH2000) shown in Fig. 1. The activities include data collected from both ACE and non ACE participants in Europe and US during a 3 year period.

Development of ground equipment for atmospheric propagation assessment from 10 up to 90 GHz

Abstract: The “Atmospheric Propagation and Profiling System” (ATPROP) advanced ground-based microwave radiometer, for radiowave propagation assessment at Ku, Ka, Q/V and W bands has been developed. The design of ATPROP is based on the requirements of SatCom, SatNav systems and Space Science Missions. ATPROP consists of two independent subsystems, operating at Ka band, near the 60 GHz oxygen absorption band and at 15/90 GHz. ATPROP has a full non-GEO satellite tracking capability and uses switched Dicke references to improve stability. Its performance allows to accurately derive atmospheric attenuation, sky noise, wet delay, and cloud, vapor and air temperature profiles.

Design and simulation of a RF MEMS shunt switch for Ka and V bands and the impact of varying its geometrical parameters

Abstract: RF MEMS plays an important role in microwave switching. The high performance of RF MEMS shunt such as high bandwidth, low insertion loss, and high isolation have made these switches well suitable for high performing microwave and millimeter wave circuits. This paper presents a RF MEMS shunt capacitive switch for Ka and V band application. This paper investigates the effect of various geometrical parameters on RF characteristics of the switch. The simulation results are presented and discussed.

Multi-antenna system based on substrate integrated waveguide for Ka-band traffic-monitoring radar applications

Abstract: In this paper, a multi-antenna system designed with one antenna for transmitter and the other three for receiver is proposed and demonstrated for Ka-band traffic-monitoring radar applications with simultaneous functionality of range, velocity and angle detection. Each antenna consists of 4×20 substrate integrated waveguide (SIW) slot array for wide azimuth field of view and low ground reflection. The scan angle of +5/−5 degree in azimuth plane (E-plane) for two receiver antennas, respectively, is simply realized by rotating the compact feeding network with a specific angle. The design details are given and the isolation between antennas with different orientations is also investigated. The prototyped antenna has a measured gain of about 22 dBi and side lobe suppression of 20 dB in the H-plane, while the bandwidth for the 10-dB return loss is 1.25 GHz.

Ka-band waveguide hybrid combiner for MMIC amplifiers with unequal and arbitrary power output ratio

Abstract: The design, simulation and characterization of a novel Ka-band (32.05±0.25 GHz) rectangular waveguide branch-line hybrid unequal power combiner is presented. The manufactured combiner was designed to combine input signals, which are in phase and with an amplitude ratio of two. The measured return loss and isolation of the branch-line hybrid are better than 22 and 27 dB, respectively. The application of the branch-line hybrid for combining two MMIC power amplifiers with output power ratio of two is demonstrated. The measured combining efficiency is 92.9% at the center frequency of 32.05 GHz.

Ka Band power limiter for satellite channel amplifier

Abstract: Some Ka-Band payloads request an anti-jamming capacity to be protected against RF interference attacks. This performance can be provided by Thales Alenia Space Ka-Band channel amplifiers thanks to the new Ka-band hard limiter. The power limiter presented in this paper allows to perform this limitation over a 10 dB power dynamic range in the frequency band 20.2 – 20.9 GHz providing in addition tuning capabilities and taking into account the design de-rating rules mandatory for space application.

Development of a Compact KA-Band Antenna Pointing Mechanism for Intersatellite Links on Small Satellites

Abstract: The Institute of Astronautics (LRT) at Technische Universitat Munchen is currently developing a lightweight, high data-rate, intersatellite-link antenna (LISA) in the Ka-band for application on small satellites. The driving design constraint to the pointing mechanism is a compact envelope of the satellite. For this reason a non-gimbal two-degree-of-freedom pointing design was chosen. Two-low loss Ka-band wave guide rotary joints have to be introduced for the signal transmission from the antenna into the satellite. This paper will present the design solutions and constructional details for a precise pointing and the implementation of the Ka-band rotary joints.

Development of a large Ka band waveguide array for digital beamforming application

Abstract: We have presented the design, analysis and development of a Ka band digitally beamformed 1mx1m slot array. The array was found to be successful in meeting the objectives of GLISTIN demonstration antenna, especially with respect to the difficult 0.042° relative beam alignment between sticks.

Ka band high power AlGaAs PIN diode switches

Abstract: In this paper we present the design and performance of millimeter wave MMIC switches in the patented MA-COM AlGaAs heterojunction PIN Diode process that allow us to produce high power and low insertion loss devices. The design process from a reflective SPDT switch to a non-reflective version of the switch, with intense use of HFSS and ADS software, is presented. These switches were designed to meet demanding requirements: low insertion loss less than 0.8 dB, 40dBm peak power and 37dBm CW power, and 30dB isolation.

Millimeter-Wave Sensor With FMICW Capabilities for Medium-Range High-Resolution Radars

Abstract: Frequency-modulated continuous-wave (FMCW) radars offer many advantages such as low peak power, low probability of interception, low interference with other systems, and high-range resolution. However, their major drawback is the isolation required between the transmitter and receiver that typically leads to the use of two separate antennas for transmission and reception. Some schemes have been proposed to enable FMCW radars to operate with a single antenna, such as frequency-modulated interrupted continuous-wave (FMICW) technology. Recently, a stagger procedure has been proposed to overcome the problems associated with the use of the FMICW technique in high-resolution radars. The technique was tested using simulated data. Now, a high-resolution millimeter-wave radar sensor, in Ka-band, has been developed at the Universidad Politecnica de Madrid, Madrid, Spain, to perform an experimental validation of the theoretical approach of the stagger procedure. The sensor transmits a linear frequency-modulated interrupted continuous wave with a maximum bandwidth of 2 GHz and a transmitted power of +29 dBm.