Showing papers on "Ka band published in 2012"

A $Ka$ -Band Fully Tunable Cavity Filter

Abstract: A TE011Ka-band tunable filter with a stable and continuous tuning performance is presented in this paper. Both bandwidth and center-frequency tunability are demonstrated by cascading six-pole pseudo-low-pass and pseudo-high-pass tunable filters. A novel mode-splitter resonator and coupling configuration enabling cross-coupled planar TE011 filter realization is introduced in this paper. The concept can be applied to back-to-back coupled TE011 resonators as well. The filter design is verified through fabrication of multiple tunable filters that demonstrates 500 MHz of tuning range with a stable RF tuning performance.

Ka-Band Phased Array Antenna for High-Data-Rate SATCOM

Abstract: The general issue of this letter deals with the design of a phased array antenna for high-data-rate SATCOM. A final demonstrator antenna could be installed on an unmanned aerial vehicle (UAV) to communicate with a satellite in Ka-band. First, a compact reflection-type phase shifter is designed and realized. Second, the conception of a phased array antenna prototype is detailed. Third, a new calibration method is involved that can provide the bias voltage to be applied to each phase shifter in order to scan the beam in the desired direction.

High efficiency Ka-band power amplifier MMICs fabricated with a 0.15µm GaN on SiC HEMT process

Abstract: The design and performance of two high efficiency Ka-band power amplifier MMICs utilizing a 0.15µm GaN HEMT process technology is presented. Measured in-fixture continuous wave (CW) results for the 3-stage amplifiers demonstrates 8–9W of output power for the balanced MMIC and 4.5–6W for the single-ended configuration. The associated power added (PAE) efficiency of both amplifiers exceeds 25% at Ka-band. The die sizes for the balanced and single-ended MMICs are 2.55×3.80mm2 and 1.39×3.42mm2 respectively.

A 17–35 GHz Broadband, High Efficiency PHEMT Power Amplifier Using Synthesized Transformer Matching Technique

Abstract: This paper presents a 17 GHz to 35 GHz broadband power amplifier (PA) using 0.15-μm GaAs pHEMT technology. The synthesized transformer using microstrip line matching technique is proposed in this PA design to enhance the broadband frequency response and minimize the chip size. The design procedures are also presented. A high efficiency broadband PA in commercial 0.15 μm GaAs pHEMT process with the best P1dB of 22 dBm, Psat of 23.5 dBm, and PAE of 40% are demonstrated to verify the design concepts. This PA has the highest PAE, smallest chip size, and wide fractional bandwidth among the broadband GaAs HEMT PAs from K to Ka band.

A Large-Scale Space-Time Stochastic Simulation Toolof Rain Attenuation for the Design and Optimization of Adaptive Satellite Communication Systems Operating between 10 and 50 GHz

Abstract: The design and optimization of propagation impairment techniques for space telecommunication systems operating at frequencies above 20 GHz require a precise knowledge of the propagation channel both in space and time. For that purpose, space-time channel models have to be developed. In this paper the description of a model for the simulation of long-term rain attenuation time series correlated both in space and time is described. It relies on the definition of a stochastic rain field simulator constrained by the rain amount outputs of the ERA-40 reanalysis meteorological database. With this methodology, realistic propagation conditions can be generated at the scale of satellite coverage (i.e., over Europe or USA) for many years. To increase the temporal resolution, a stochastic interpolation algorithm is used to generate spatially correlated time series sampled at 1 Hz, providing that way valuable inputs for the study of the performances of propagation impairment techniques required for adaptive SatCom systems operating at Ka band and above.

Radar sensors for hump yard and rail crossing applications

Abstract: A radar sensor as part of the automatic shunting system has been developed for the remote control of track occupancy in the hump yard and railroad switch territories, enhanced by the speed control of rolling stock when it passes by the retarder. The sensors are equipped with systems of remote control. They are provided with systems of internal parameter diagnostics and transmission of the radar and service information to the control point and can work in information networks.

Design and development of a surface micro-machined push-pull-type true-time-delay phase shifter on an alumina substrate for Ka-band T/R module application

Abstract: A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on the distributed MEMS transmission line (DMTL) concept towards maximum achievable phase shift with low actuation voltage with good figure of merit (FOM) is presented in this paper. This surface micro-machined analog DMTL phase shifter demonstrates low power consumption for implementation in a Ka-band transmit/receive (T/R) module. The push–pull-type switch has been designed and optimized with an analytical method and validated with simulation, which is the fundamental building block of the design of a true-time-delay phase shifter. Change in phase has been designed and optimized in push and pull states with reference to the up-state performance of the phase shifter. The working principle of this push–pull-type DMTL phase shifter has been comprehensively worked out. A thorough detail of the design and performance analysis of the phase shifter has been carried out with various structural parameters using commercially available simulation tools with reference to a change in phase shift and has been verified using a system level simulation. The phase shifter is fabricated on the alumina substrate, using a suspended gold bridge membrane with a surface micromachining process. Asymmetric behaviour of push–pull bridge configuration has been noted and a corresponding effect on mechanical, electrical and RF performances has been extensively investigated. It is demonstrated 114° dB−1 FOM over 0–40 GHz band, which is the highest achievable FOM from a unit cell on an alumina substrate reported so far. A complete phase shifter contributes to a continuous differential phase shift of 0°–360° over 0–40 GHz band with a minimum actuation voltage of 8.1 V which is the highest achievable phase shift with the lowest actuation voltage as per till date on the alumina substrate with good repeatability and return loss better than 11.5 dB over 0–40 GHz band.

Itu regulations for ka-band satellite networks

Abstract: This paper gives an overview of the ITU regulations that apply to Ka-band satellite networks that operate in the geostationary satellite orbit (GSO) or a non-geostationary satellite orbit (non-GSO). In the last 5 years many satellite operators have launched or are planning to launch so-called High Throughput Satellites (HTS) operating in the Ka-band. Characteristics and examples of HTS will be given. Most HTS typically file for 3.5 GHz bandwidth in the following Ka-bands: 27.5 – 31 GHz (uplink) 17.7 – 21.2 GHz (downlink) These bands are subject to several regulatory provisions which restrict the bandwidth available. Using a simplified view of the Ka-band portion of the Table of Frequency Allocations the paper will explain the ITU regulations as they apply in each of the cases: • Bands identified for High-Density FSS (HDFSS) • Bands used by many administrations for FS including LMDS • Bands where GSO and non-GSO satellite networks have equal rights • Bands where equivalent pfd (epfd) applies • Military bands Some WRC-12 results are also reviewed including new BSS Ka-band allocations in the downlink band 21.4 – 22 GHz, clarification of the concept of “bringing into use” and what the Radio Regulations Board considers to be “reliable” information in case of a dispute.

CW Ka-Band Kilowatt-Level Helical-Waveguide Gyro-TWT

Abstract: Experimental results and design details are presented on an amplifier setup based on a helical-waveguide gyrotron traveling-wave tube delivering continuous-wave kilowatt-level output power with an instantaneous frequency bandwidth of about 3%.

A 30GHz 2dB NF low noise amplifier for Ka-band applications

Abstract: A 30GHz Ka-band low noise amplifier (LNA) has been realized in a 0.25µm SiGe:C BiCMOS technology. A noise figure (NF) of 1.8–2.2 dB has been measured at 26–32 GHz. The achieved 3dB-power bandwidth is larger than 7GHz, with a peak gain of 12.4dB at 29.2GHz. The input 1 dB compression point (ICP 1dB ) is −11dBm and input IP3 is −1.3dBm at 30GHz for a total power consumption of 98mW. The chip area including bond pads is 1mm×0.7mm.

Link adaptation for Ka band low Earth orbit Earth Observation systems: A realistic performance assessment

Abstract: SUMMARY In this paper, a proposal is sketched for realizing high data rate downlinks in next-generation Ka band low Earth orbit (LEO) Earth Observation (EO) systems. The work aims at realistically assessing the throughput advantage stemming from link adaptation strategies—embraced by most wireless and satellite communication standards—compared with non-adaptive transmission, which is the approach followed in conventional X band EO systems. The transmission strategies examined include constant, (static and dynamic) variable, and adaptive flavors of coding and modulation, each representing a different performance/system complexity trade-off. Practicality is pursued to the extent possible by incorporating state-of-the-art orbital, ground station, spacecraft, propagation, physical layer, and system implementation characteristics. The results manifest that under particular conditions, link adaptation offers throughput improvements of up to 100% against non-adaptive transmission schemes in Ka band LEO EO systems. Copyright © 2012 John Wiley & Sons, Ltd.

A dual-band multimode monopulse tracking antenna for land-mobile satellite communications in Ka-band

Abstract: The growing interest in bi-directional mobile satellite communications in Ka-band necessitates the development of dedicated antenna systems and feeds. In this paper we describe a mobile satellite communications terminal with a cassegrain reflector antenna fed from a multimode monopulse tracking system for circular polarisation at the satellite downlink frequency of 20 GHz. The structure is operational at 30 GHz as well, to cover the uplink frequency range. The antenna system is mounted on a high-performance mechanical positioner to facilitate a fast compensation of the movements of the carrier vehicle. This work contributes to the development of a satellite terminal for mobile communications in disaster scenarios [1].

A Ka-Band Broadband Integrated Transition of Air-Filled Waveguide to Laminated Waveguide

Abstract: In this letter, a novel compact and broadband integrated transition between a laminated waveguide and an air-filled rectangular waveguide operating in Ka band is proposed. A three-pole filter equivalent circuit model is employed to interpret the working mechanism and to predict the performance of the transition. A back-to-back prototype of the proposed transition is designed and fabricated for proving the concept. Good agreement of the measured and simulated results is obtained. The measured result shows that the insertion loss of better than 0.26 dB from 34.8 to 37.8 GHz can be achieved.

A tunable band-stop filter using a metamaterial structure and MEMS bridges on a silicon substrate

Abstract: A band-stop filter using a metamaterial structure (complementary U-shaped split resonator; CUSR) on a silicon substrate with a 13% tuning range is presented for Ka band applications. The metamaterial structure is used as a frequency-selective geometry on a coplanar waveguide (CPW) and tunability is achieved with the help of MEMS bridges. The rejection in the stop band is around 25 dB for the entire tuning range. A low insertion loss of 0.5 dB is obtained in the pass band. A simple electrical model of the proposed device and the design guidelines are presented. The filter is realized by a novel fabrication methodology involving the micromachining of two bonded silicon wafers and initial fabricated results are reported.

The Ka-band 10-kW continuous wave gyrotron with wide-band fast frequency sweep

Abstract: The dual-frequency gyrotron with fast 2% frequency sweep at about 28 GHz is designed to power an electron cyclotron resonance ion source (ECRIS). Operation with an output power of up to 10 kW in CW mode and efficiency of 20% was demonstrated at both frequencies. Frequency manipulation has a characteristic time of about 1 ms and is based on magnetic field variation with an additional low-power coil. Fast frequency sweep will supposedly increase the ion current and the average ion charge of ECRIS. The possibility of 100% power modulation is demonstrated using the same control method.

Wide band Ka-band Coupled-Cavity Traveling Wave Tube (CCTWT) development

Abstract: A series of Ka-band Coupled-Cavity Traveling-Wave Tubes (CCTWTs) has been successfully developed, built, and tested at Communications and Power Industries (CPI) in collaboration with the Naval Research Laboratory (NRL) and SAIC. These devices represent a significant advance in the state-of-the-art of millimeter-wave CCTWTs, exploring the limits of power, bandwidth, and stability. We discuss the design and successful demonstration of the series of CCTWT's, including the VTA-6430N1 prototype which achieved over 700-W (879-W maximum power) over a 5-GHz range in Ka-band.

U-shaped microstrip meander-line slow-wave structure for Ka-band traveling-wave tube

Abstract: Study on U-shaped microstrip meander-line slow-wave structure for a low voltage, wide bandwidth millimeter traveling-wave tube is presented. The electromagnetic characteristics and the sheet beam-wave interaction of this structure are carried out. The simulation results predicts that this millimeter-wave power amplifier is capable of delivering hundreds of watts output power in the frequency range of 29–38 GHz, and the peak power is about 200 watts with the correspond-ding gain of 33 dB at 35 GHz.

Centre-fed series array antenna for K-/Ka-band electromagnetic sensors

Abstract: This study introduces a novel series array antenna for passive millimeter wave sensor applications, particularly physical securities and vigilance sensors. The antenna is mainly composed of a three-line series array and has a symmetrical structure whereby a `Chebyshev polynomial` has been used to obtain a low side-lobe characteristic. For a more symmetrical antenna pattern, the authors considered a centre feeding structure from an input port to the three individual linear arrays. This feeding structure is very helpful when it comes to designing centre-fed and non-edge-fed multi-line linear arrays with low dividing losses. For the verification of the array design, the authors implemented the feeding structure to a K-band electromagnetic (EM) sensor antenna. This array was fabricated on a printed circuit board, and showed good performance to satisfy the required specification for an EM sensor. The authors designed another Ka-band array with the same structure as the K-band model, and found that the gain of the array can be increased by controlling the inclined angle of the side wings. Using the side wings, the authors were able to realise high gain performances in conformal size without variation in other types of performance.

Microwave radar signatures of precipitation from S band to Ka band: application to GPM mission

Abstract: Radars at different frequencies have been used over five decades for observing precipitation. S and C bands have been employed for long range coverage observations. Dual-polarization X-band radars ...

Distribution characteristics and performance simulations of rain attenuation at Ka band for satellite communications

Abstract: In satellite communication system, rain attenuation is one of the most important reasons for the signal fading transmitted at Ka band (30/20GHz). In this paper, based on the ITU recommendation rainfall attenuation prediction model, we obtain the rainfall attenuation value of one specific area in satellite communication systems at Ka band, in premise of knowing that rain attenuation value of a certain area follows lognormal distribution, then statistical distribution parameters are derived in detail by a method of the least squares curve fitting. After QPSK modulation, signal is polluted by additive noise in AWGN channel. We analyze and simulate the effect of light rain and heavy rain on signal propagation. The simulation results indicate that rain attenuation makes the signal-to-noise ratio and the bit error rate worse.

Compact Ka-Band One-Port Vector Reflectometer Using a Wideband Electronically Controlled Phase Shifter

Abstract: In this paper, the design and implementation of a compact one-port Ka-band (26.5-40 GHz) vector reflectometer or network analyzer (VNA), operating in full Ka-band frequency range, are presented. The design follows that of a recently developed VNA but with the goal of producing a wideband version. The most critical component of this design is a wideband electronically controlled phase shifter, designed using nonuniformly spaced p-i-n diode-loaded slots incorporated in the broad wall of a rectangular waveguide. Nonuniform placement of the slots is shown to significantly reduce unwanted resonances within the operating bandwidth. Also, the new design provides the possibility of using a more accurate three-port S -parameter characterization instead of the previously used two-port approach. The design foundation and measurement results are presented.

700 W Ka-band Coupled-Cavity Traveling Wave Tubes (CCTWT) for communication

Abstract: A family of 700-W Ka-band Coupled-Cavity Traveling-Wave Tubes (CCTWTs) has been successfully developed, built, and tested at Communications and Power Industries (CPI). These CCTWTs are capable of up to 700-W Continuous Wave (CW) output power with 2.0 GHz of instantaneous bandwidth. They were built with the intended use for the commercial satellite and military communication market. We discuss the design and successful demonstration of the family of CCTWTs, including the VTA-6428S2B prototype which achieved over 700-W (783-W maximum output power) with an overall efficiency reaching as high as 52%.

Interferometric Ka-band SAR with DBF capability

Abstract: An interferometric SAR (InSAR) Ka-band instrument is presently being studied under ESA contract. At Ka-band, a single-pass single-platform interferometric SAR instrument with Digital Elevation Map performance at HRTI-3 standard level seems feasible. An architecture developed under this contract is described. It depends heavily on the digital beam forming techniques SCORE and MAPS. Design considerations and InSAR performances are reported.

Stabilized Photonic Links for Deep Space Tracking, Navigation, and Radio Science Applications

Abstract: Stable fiber optic links have been operational in NASA's DSN for over 20 years providing distribution limited fractional frequency stability below 10-14 at one second and reaching 10-18 at approx 10,000 seconds. We summarize recent stabilized photonic link developments for DSN operation capable of high performance and reliability, and at much lower cost than previous systems. Recent research has focused on two applications, 1) actively stabilized links to transport 100 MHz metrology frequency references to sites up to 30 km from the central atomic frequency standard, and 2) stabilized links transporting broadband S, X, and Ka band signals used in deep space tracking and navigation and antenna arraying applications.

A Ka-Band Second Harmonic Gyroklystron Amplifier

Abstract: The design and experiment of a ka-band second harmonic gyroklytron amplifier are reported. The three-cavity 35-GHz second harmonic gyroklystron operates in the TE021 circular electric mode. Based on the numerical simulation, a three-cavity, second harmonic gyroklystron amplifier prototype has been fabricated. Experiments show a peak output power of 212 kW at 35 GHz with a 3-dB bandwidth of 155 MHz (0.44%) when utilizing a 58 kV, 23 A, v⊥/vP = 1.45 electron beam from a magnetron injection gun. The efficiency is approximately 16%, and the gain is about 24 dB.

A ka-band broadband active frequency doubler using CB-CE balanced configuration in 0.18 µm SiGe BiCMOS process

Abstract: A Ka-band broadband frequency doubler in a 0.18 µm SiGe BiCMOS technology is presented in this paper. The frequency doubler employs a configuration of a common-base (CB)/ common-emitter (CE) pair to enhance the second harmonic efficiently. This frequency doubler features a conversion gain of higher than ™7 dB with an input power of 5 dBm between 26 and 40 GHz. The maximum output 1-dB compression point (P 1dB ) is 4.3 dBm and the output saturation power (P sat ) is higher than 5 dBm at 31 GHz. The overall chip size is 0.85×0.66 mm2. To the best of the author's knowledge, this work demonstrates the first SiGe-based frequency doubler using CB-CE configuration with good output power and good figure-of-merit (FOM) covering the entire Ka band.

PLATON: Satellite remote sensing and telecommunication by using millimetre waves

Abstract: Nowadays, climate and meteorology assumed a fundamental role in manifold domains with the aim to understand how they affect life in modern society. Such a new sensitivity is the result of a major awareness of the Earth health and the need of better understanding the increasing climatic and meteorological changes recently observed. Actually, in the last years several satellite missions, single and cooperative, have been proposed and developed by NASA, ESA and JAXA. They aim at studying the overall atmosphere, its main elements and their close relations. On the other hand, in a different domain such as telecommunications, the low frequency bands crowding and the increase of broadband services diffusion has created the premises for the development of studies on the characterization and the development of telecommunications in the millimetric band not yet explored for this purpose (Q-V bands-35–75 GHz, W band-75–110 GHz). Actually, nowadays satellite telecommunications at Ka band can be considered a standard for broadband services. Higher frequencies such as Q-V bands are currently employed for military applications (SICRAL satellite of the Italian Defence Ministry) and soon for scientific applications (TDP#5 payload on-board the ESA Alphabus platform [1]). W band can be considered as the most important scientific frontier within the broadband satellite communications, since no satellite system operating at such a frequency has been developed, just studies such as DAVID and WAVE [2][3][4]. In the last years these fields registered a convergence of research activities towards the use of electromagnetic radiation at millimetre wavelengths, i.e. the EHF band (Extremely High Frequency, 30–300 GHz). In telecommunications the use of carriers at higher frequency implies theoretically the possibility of using wide bandwidth and hence greater data rate in down link. In the field of weather and climate satellite observations, the technology advancements of the last 10 years make available several sensors (radar, lidar, radiometers, etc.) in the 30–300 GHz band. They allow, by means of observations unpredictable some years ago, for broadening the knowledge of meteorological and climatological phenomena and the improvement of predictive models. However, the capability of collecting large data volumes leads to a related capability of transmitting the data to ground within reduced visibility windows. An integrated TeLeCommunication-Earth Observation approach (TLC-EO) could satisfy both needs. ARES (Advanced Research and Engineering for Space), a consortium constituted both by scientific institutions (the University of Rome Tor Vergata) and industrial partners (Rheinmetall Italy and TECS, TEchnological Consulting Services) carried out a feasibility study to investigate an innovative satellite devoted both to Earth remote sensing and to high frequency telecommunications. Both payloads are based on the common use of millimetric band to exploit the favourable characteristics of such high frequencies. The study is called PLATON (PayLoad for Advanced Telecommunication, Observation and Navigation) [5].

Experimental research on high resolution terahertz radar imaging

Abstract: The design and realization of a terahertz(THz) radar system with 0.14 THz carrier frequency and 5 GHz bandwidth have been presented. The Ka band signal was frequency-doubled to be used as the local oscillator signal for sub-harmonic mixer in the systems transceiver chain. For the transmitted signal was a linearly frequency-modulated continuous-wave(LFM-CW), the dechirp technique was used in the THz radar receiver front end. By using this THz radar system, 3 cm high resolution range profiles were obtained as well as inverse synthetic aperture radar(ISAR) images, which exactly represent the subtle features of targets.