Showing papers on "Ka band published in 2016"

1-Bit Reconfigurable Unit Cell for Ka-Band Transmitarrays

Abstract: This letter presents an electronically reconfigurable, linearly polarized unit cell for transmitarray applications in Ka-band. A 1-bit phase resolution (namely with two phase states 0 ° and 180 °) is obtained using two p-i-n diodes mounted on a slot-loaded patch antenna. The design, realization, and experimental characterization in a standard waveguide simulator are reported. The measured insertion losses only reach 1.09 and 1.29 dB for the two-phase states, respectively, with a 3-dB transmission bandwidth of about 11.2%.

Satellite communication and propagation experiments through the alphasat Q/V band Aldo Paraboni technology demonstration payload

Abstract: Current high-throughput satellite (HTS) systems for broadband distributed user access are designed following two main concepts: ▸ The use of Ka band radio frequency (RF) links both for the forward and for the return link; this choice is due to the congestion of lower frequency bands and to the relatively large bandwidth available in the Ka band. Moreover, the RF technology in the Ka band is mature [1], [2]. ▸ The use of multispot coverage: this technique is largely applied to increase the system throughput through frequency reuse and system reconfigurability [2], [3].

Radiating Elements for Shared Aperture Tx/Rx Phased Arrays at K/Ka Band

Abstract: A dual-band, Tx/Rx, self-diplexing phased array is presented. The antenna has been designed to cover Tx/Rx satellite communications at K/Ka band with a frequency ratio 1.5:1. To obtain dual-band operations with a single radiating surface, a novel dual-band radiator is adopted and placed in a configuration in which dual-band and single-band elements are interleaved. The proposed configuration reduces the number of radiating elements required by other solutions while avoiding the insurgence of grating lobes. The tightly packed arrangement of the elements poses many integration issues, which are solved with a novel integration technique. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

A Ka-band digitally-controlled phase shifter with sub-degree phase precision

Abstract: We present a passive digital-to-phase converter with sub-degree phase precision for phased array frontends. The phase tuning approach is based on manipulating the electromagnetic properties of an artificially constructed transmission line. By simultaneously controlling dispersion, characteristic impedance, and loss across the structure, the phase shifter minimizes phase imprecisions while ensuring a flat amplitude response across different phase settings. The chip prototype is fabricated in a 130nm SiGe BiCMOS process, occupies an area of 0.18mm2, and consumes no power. The insertion loss is −9.3 dB ± 0.25 dB at 28 GHz. The phase control operates with 4.75 degree steps while maintaining an RMS phase error of 0.6 degrees across multiple chips and temperatures, demonstrating the best phase and amplitude accuracy when compared to state-of-the-art integrated microwave and mm-wave phase shifters.

Ka-Band LNA MMIC's Realized in Fmax > 580 GHz GaN HEMT Technology

Abstract: We report the first generation of GaN MMIC circuits that are based on the latest generation of (ft > 320 GHz and fmax > 580 GHz) [1] GaN Transistors. The reported broadband Ka-band (27 GHz - 40 GHz) GaN LNA MMIC's have Noise Figure (NF) as low as 1 dB measured at a frequency of 37 GHz, NF 24dB of gain across 28 GHz- 39.2 GHz frequency range, and a very broad range of usable DC bias conditions (Vd: 0.6V - 4V; Pdc: 5 mW- 310 mW). This is to the best of our knowledge the lowest NF reported for GaN LNA in this frequency band.

Multi-spot beam reflectarrays for satellite telecommunication applications in Ka-band

Abstract: This paper describes a reflectarray concept that can produce a full dual-band (transmit/receive) multiple spot beam coverage in Ka-band using only two main apertures while maintaining single-feed-per-beam operation The proposed concept combines the capabilities of the reflectarray and a parabolic surface, enabling the antenna to radiate more than one beam types in the typical “4-color” frequency polarization re-use scheme Preliminary results using single-band array elements are presented and confirm the potential of the proposed concept

Ka-Band User Terminal Antennas for Satellite Communications [Antenna Applications Corner]

Abstract: The growing need for bidirectional mobile satellite communications in the Ka-band necessitates the development of dedicated antenna systems. In this article, we describe two different solutions for mobile user-terminal antennas intended for an operation in emergency scenarios. The first solution, a high-gain antenna, consists of a Cassegrain reflector, fed from a multimode monopulse tracking system for circular polarization at a satellite downlink frequency of 20 GHz. The structure is operational at 30 GHz 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. The second solution, a low-profile antenna, consists of leaky-wave antenna (LWA) panels employing two-layer partially reflective surfaces (PRSs). A hybrid tracking technique is used, and a unique feature of this antenna is its dual-band operation, to overcome the challenge of widely separated uplink and downlink ranges in the Ka-band. This article describes the design of the two types of antennas and analyzes the measurement results. Furthermore, tracking issues considered from the view of control engineering are addressed, and an evaluation of tracking accuracy is presented.

An Ultra Compact Watt-Level Ka-Band Stacked-FET Power Amplifier

Abstract: An ultra-compact watt-level Ka-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) is demonstrated using a 0.15 $\mu\text{m}$ Gallium Arsenide (GaAs) stacked field effect transistor (stacked-FETs) configuration. The fabricated PA exhibits 31.5 dBm output power, 17 dB gain and 33% power added efficiency (PAE). The bandwidth is from 26 GHz to 31 GHz. The PA achieves 0.7 Watt/mm2 power density at 28 GHz. To the best of our knowledge, this PA achieves the highest power density among reported GaAs Ka-band PAs.

A Fully Integrated Ka-Band Front End for 5G Transceiver

Abstract: We present the design and measured results of a fully integrated Ka-Band front end on a 0.15-µm GaAs pHEMT process. The integrated front end includes a three stage power amplifier, three stage low noise amplifier, and single pole, double throw switch. The integration of the front end is a crucial step to commercialize mm-Wave technology for 5G mobile communication. In addition to the fully integrated front end module, these three components were fabricated separately for individual characterization and analysis, and those results are presented in this paper.

High-efficiency microstrip rectenna for microwave power transmission at Ka band with low cost

Abstract: This paper presents the design and implementation of a high-efficiency microstrip rectenna for millimetre wave power transmission (MMPT) at Ka band with low cost. An experimental method is suggested to obtain the input impedance of the rectifying diode at millimetre-wave bands. So the high-efficiency rectifying circuit could be designed with an effective input impedance match network and two output class-F dc-pass filters. A high-gain Fabry-Perot resonator antenna with circularly polarised (CP) operation and harmonic suppression function is proposed as the receiving antenna, which has a measured 3-dB axial-ratio bandwidth of 6.5% and peak gain of 17 dBi at the centre frequency of 35 GHz. The antenna is fed by a microstrip line, which is the same as the input port of the rectifying circuit, so the integration of the rectenna is easy. The millimetre wave to direct current (MMW-DC) efficiency of the rectenna has been measured in far field, which shows a good CP performance. A more precise measurement system, which could be applied both in near and far fields, is proposed to evaluate the rectenna efficiency. The highest efficiency of 63.8% is measured on the load of 430 Ω at 34.8 GHz with the received power being 77.3 mW.

6W Ka Band Power Amplifier and 1.2dB NF X-Band Amplifier Using a 100nm GaN/Si Process

Abstract: This paper presents the measured results of two circuits fabricated with a millimeter wave 100 nm Gallium Nitride on Silicon (GaN/Si) process. The first circuit is a 27-34 GHz power amplifier, presenting 6 W of output power in pulsed operation and 5.6 W in CW operation. The second circuit, using exactly the same process, is a 8-12 GHz Low Noise Amplifier presenting 1.3 dB noise figure from 11 to 13 GHz.

A compact Ka-band waveguide orthomode transducer fabricated by 3-D printing

Abstract: This paper presents an orthomode transducer (OMT) fabricated using 3-D printing. The OMT is designed to operate at two frequency bands, with each band passing an orthogonal polarization. For one polarization the band is 17–22 GHz and the other 27–31 GHz. Both polarizations are combined into a common port with square waveguide cross section. To facilitate the measurement, two tapered waveguide transitions are designed to convert the square waveguide port to standard WR-42 and WR-28 waveguides. The OMT and the waveguide transitions are made from polymer using stereolithography based 3-D printing and a 5 μm thick copper layer is deposited on them. The experimental results of the OMT are compared with simulations and discussed.

Circularly Polarized Slotted Waveguide Array With Improved Axial Ratio Performance

Abstract: This communication demonstrates experimentally the improvement in axial ratio performance when a slot is combined with a set of three parasitic dipoles instead of one. The analysis is performed in the context of slotted-waveguide arrays and SATCOM applications in Ka band, where a bandwidth specification as wide as 7.5% can be demanded.

A Wideband Microfabricated Ka-Band Planar Helix Slow-Wave Structure

Abstract: A Ka-band planar helix slow-wave structure (SWS) which is suitable for microfabrication is proposed and its design is described in this paper. A wideband design is achieved by using dispersion control techniques. The design shows an $S_{11}$ better than −20 dB over a 42.8% cold-test bandwidth with discrete input and output ports. Cold-test results for coplanar waveguide ports are also presented. The hot-test parameters of the SWS with discrete ports are investigated using CST Particle Studio. For an elliptical cross-sectional electron beam with the beam voltage of 3.72 kV and the current of 50 mA, a 3-dB small-signal gain bandwidth of 48.5% and a maximum gain of 42 dB are achieved. Saturated power of 26.5 W is achieved by using pitch tapering. Hot-test performance of the proposed SWS including a sever for high gain applications is also presented. Thermal simulations using CST have been carried out showing that the proposed SWS can have very good thermal dissipation properties. RF electric field values at some critical locations in the SWS have also been examined from the point of view of dielectric breakdown.

Metallic 3D printed Ka-band pyramidal horn using binder jetting

Abstract: Metallic RF-Microwave components fabricated using additive manufacturing are continually being demonstrated as viable solutions in terms of cost and performance when compared to components fabricated by traditional methods such as machining. In this work, binder jetting is used to fabricate a Ka-Band pyramidal horn antenna, as a test structure to evaluate the performance of this metal 3D printing technology. The measured parameters (S 11 and radiation pattern) have good agreement with the simulated ones. The measured return loss is >20 dB across the band. The simulated antenna gain is 8.43 dBi (at 26.5 GHz), and simulations show that the performance degradation due to the finite conductivity and surface roughness is less than 0.1 dBi.

A Ka-band substrate-integrated waveguide diplexer with wide frequency spread

Abstract: A compact 20 GHz/30 GHz diplexer for satellite communication systems is presented. It consists of a T-junction and two bandpass filters implemented in substrate-integrated waveguide (SIW) technology. The 30 GHz filter relies on a standard design, whereas a wide stopband approach is used for the 20 GHz filter to suppress a parasitic passband at the upper frequency. The design procedure is explained and simulation as well as measurement results are presented. The complete diplexer is fabricated in a standard PCB process. The measurement results validate the approach.

Parabolic deployable antenna

Abstract: A deployable antenna is described. The antenna comprises a mesh attached to foldable ribs, a hub and a sub-reflector. The antenna can be stowed in a tight space for launching in space, and later deployed by extending out of its container. The antenna is designed to work in the Ka band or other bands and can increase data rates and function as a radio antenna.

Ka-Band Circularly Polarized Reflectarray: Using a Double-Layers Cross Slot

Abstract: In this article, a broadband circularly polarized (CP) reflectarray (RA) is presented. A Ka-band multilayer-CP RA antenna is designed and further validated through measurements. The two orthogonal slot arms are angularly rotated for the phase compensation in the RA design. A 25 t 25 RA with a physical area of 90 t 90 mm2 (9 t 9 lo2) is designed for broadside radiations. The elements at an RA surface are excited by a wideband CP horn. An excellent CP performance is achieved with broadband matching and 3-dB axial ratio covering the entire band.

From S-band mobile interactive multimedia to fixed satellite interactive multimedia: making satellite interactivity affordable at Ku-band and Ka-band

Abstract: This paper describes the evolution of the ETSI S-band mobile interactive multimedia protocol to support fixed satellite interactive multimedia F-SIM services exploiting existing Ku-band and Ka-band satellites. The key F-SIM protocol differences for both physical and upper layers are described and justified. The F-SIM protocol has been adopted by the recently deployed Eutelsat Broadcast Interactive System whose architecture, key system parameters, link budget examples and key composing elements are also described. Finally, a summary of laboratory and field trials results over the Eutelsat KA-SAT multibeam satellite are illustrated. Copyright © 2015 John Wiley & Sons, Ltd.

Multibeam reflectarray for transmit satellite antennas in Ka band using beam-squint

Abstract: This contribution describes a design concept based on beam squint effect in printed reflectarrays that allows to produce multiple contiguous beams at 19.5 and 20 GHz, by discriminating in frequency. A 1.6-m reflectarray has been proposed to produce 10 beams separated 0.5 degree using five feeds with frequency reuse. The simulated radiation patterns show a peak gain better than 47.6 dBi, with side-lobe levels close to −22 dB. The proposed concept can be suitable for multiple spot beam satellites in Ka-band.

Ka band enabling technologies for high throughput satellite HTS communications

Abstract: Global demands for personal, businesses and governments connected data continue to challenge our communication technologies and infrastructure. Both wired and wireless terrestrial communications systems are realizing advancements in technologies and their applied infrastructure enhancements. These ever evolving terrestrial communication systems are providing for increased data capacity, an enhanced quality of service and a lower cost per bit for all users. Satellite systems are especially challenged in order to remain relevant for these same enhancements in order to augment and compete with these terrestrial global communication systems. In order to meet these global demands the next generation satellite communications systems are evolving by advancing their own technologies and infrastructure. The resulting next generation communication satellite systems include utilization of the Ka frequency band and also through the application of other key advancements in antenna systems and processing payloads. This paper provides an overview of many of the communication satellite system advancements which are in part enabled through the utilization of the Ka frequency band. Copyright © 2015 John Wiley & Sons, Ltd.

A High Efficiency High Power Density Harmonic-Tuned Ka Band Stacked-FET GaAs Power Amplifier

Abstract: A stacked-FET power amplifier (PA) with harmonic- tuned output matching network is demonstrated using a 0.15-µm Gallium Arsenide (GaAs) technology. The fabricated PA exhibits 28.5 dBm output power, 12 dB gain and 38.4% power added efficiency (PAE). To the best of our knowledge, this is for the first time stacked-FET technique is used in combining with harmonic-tuned output network to achieve high PAE and high power density simultaneously in a GaAs PA.

SiGe based Ka-band reflection type phase shifter for integrated phased array transceivers

Abstract: Phase shifters are key components in phased array systems. A low loss and low loss variations SiGe differential phase shifter for the Ka-band is described. This bidirectional differential reflection type phase shifter (RTPS) design employs a novel diagonal configuration for the coupler and it is controlled by a single voltage node. The measured results show state of the art insertion loss of 5±1 dB, phase tuning range larger than 180 degrees, for a frequency range of 26.5 GHz to 32.8 GHz (21%). At 30 GHz, the phase shifter exhibits insertion loss of 4.8 dB, loss variation of ±0.4 dB, and more than 206 degrees of phase shift range. The RTPS was fabricated in a standard BiCMOS SiGe process and occupies 0.64 mm2 die area.

Ka-band antenna arrays with dual-frequency and dual-polarized patch elements

Abstract: In this contribution a dual-band, dual-polarized microstrip antenna element for array applications is presented. The patch antenna is designed to operate simultaneously at around 30 and 20 GHz, the up- and downlink frequencies of modern Ka-band satellite communication systems. The antenna is smaller than half the freespace wavelength at 30 GHz to enable its utilization as array element of dual-band ground terminals. Integrating transmitter and receiver circuits allows, in turn, for a very compact active terminal solution. To minimize production cost, the design is carried out in standard multilayer printed circuit board technology. The antenna features two distinct polarization ports suitable for either dual linear or dual circular polarization if both ports are excited in quadrature. The single antenna design process is described in detail and simulation and measurement results are presented. Finally, different arrays based on this patch antenna are evaluated by simulation and measurements.

Metamaterial loaded vivaldi antenna with high gain and equal beamwidths at KA band

Abstract: A high gain and broadband Vivaldi antenna with end-fire and equal beamwidth radiation pattern at Ka band is presented in this paper. The Vivaldi slot is fed by the microstrip line-to-substrate integrated waveguide (SIW) transformer. The SIW transmission performance is enhanced by another row of metal vias beside the original one. On both sides of the Vivaldi conductor planes, 8 parallel slots with gradually increasing length are etched to improve the front-to-back ratios. Under the microstrip feed line, three pairs of split ring resonators (SRRs) are etched on the ground to suppress the secondary harmonic. In order to improve the antenna gain and obtain the equal E- and H-plane beamwidths, the special designed zero-epsilon metamaterial (ZEM) units are loaded on the Vivaldi slot with a maximum gain increment of 3.4dB being obtained. The antenna exhibits a broad bandwidth of 38.5% at 35GHz ranging from 26.5GHz to 40GHz with the reflection coefficient less than −10dB, and the gain varying between 9.7dBi and 12.2dBi. The proposed antenna is fabricated and measured to validate the design. The measured results are in good agreement with the simulated ones. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2337–2341, 2016

A spline-profiled conical horn antenna assembly optimized for deployable Ka-band offset reflector antennas in CubeSats

Abstract: With the advent of small-scale satellite technologies, there has been significant interest in developing advanced functionalities for CubeSat and SmallSat projects. Developing high-gain antennas within this paradigm opens the door for many new applications which require high data rates or narrow-beam patterns. In this paper, we discuss the optimization of a compact, spline-profile horn antenna assembly that could be used as a feed for future deployable offset reflector antennas in CubeSats.

3D metal printed Ku/Ka Band modified turnstile junction Orthomode Transducer

Abstract: Orthomode Transducers (OMTs) are key components in dual-polarized satellite communication systems Turnstile junction (TJ) OMTs are widely popular since their structural symmetry suppresses the undesired higher order modes, which degrade impedance matching and isolation of the OMT Several works on TJ OMTs operating in single (or narrow) frequency band have been published In contrast, this paper presents a modified TJ OMT designed for multiple frequency bands: Ku-Band (107 GHz–1275 GHz), lower Ka-Band (195 GHz–205 GHz) and upper Ka-Band (292 GHz–302 GHz) Unlike ordinary TJ OMT, the modified OMT besides discriminating the orthogonal polarization signals, also acts as a frequency diplexer The OMT was manufactured using cost-effective 3D metal printing The simulated and measured S-parameters were evaluated in Ku, lower and upper Ka bands The OMT functionality was verified through field test measurement

A Ka-band radial relativistic backward wave oscillator with GW-class output power

Abstract: A novel radial relativistic backward wave oscillator with a reflector is proposed and designed to generate GW-level high power microwaves at Ka-band. The segmented radial slow wave structure and the reflector are matched to enhance interaction efficiency. We choose the volume wave TM01 mode as the working mode due to the volume wave characteristic. The main structural parameters of the novel device are optimized by particle-in-cell simulation. High power microwaves with power of 2 GW and a frequency of 29.4 GHz are generated with 30% efficiency when the electron beam voltage is 383 kV, the beam current is 17 kA, and the guiding magnetic field is only 0.6 T. Simultaneously, the highest electric field in the novel Ka-band device is just about 960 kV/cm in second slow wave structure.