Ka-band Satellite Communication Research Articles

Dependence of rain attenuation on rain rate and drop size distribution for Ka-band satellite communication over India

The Raindrop size distribution (DSD) is the most effective parameter to calculate rain-induced attenuation, which can be severe at Ka-band and higher frequencies. The authors have investigated the impact of rain rate and DSD on rain-induced specific attenuation over a tropical location Kolkata, India. DSD data from disdrometer has been used to calculate the specific rain attenuation with the help of Mie scattering theorem. Low to medium drop diameters (up to 3 mm) are the largest contributors to the various classes of rain rate and attenuation. Double peaks of drop sizes are significant for medium rain rate. The contribution of smaller drop diameters decrease, whereas the contribution of higher drop diameters increase with increasing rain attenuation. At lower rain attenuation, (up to 1.5 dB), complementary cumulative distribution function (CCDF) shows higher value for stratiform rain, with respect to convective rain. The higher attenuation occurrences are mostly observed during 12–18 Indian standard time (IST), i.e., in the afternoon. The results will be helpful for Ka-band (GSAT-14) and higher frequency satellite communication channel modeling over India.

Ka-band flat panel circularly polarized antenna array for LEO satellite communication systems

In this paper, a high gain circularly-polarized antenna array with a flat panel structure for low Earth orbit (LEO) satellite communication systems is proposed. This new CP structure can efficiently achieve high directivity and can easily be integrated with beamforming ICs (BFIC) when designing an antenna module, resulting in a good candidate for Ka-band satellite communications. Furthermore, the proposed FPAA can easily be extended to a larger scale array from a base unit in a 2 × 2 sub-array structure. Each sub-array is configured by four high-gain planar segmented antenna (PSA) elements with a sequentially rotating arrangement, where a single 4-channel BFIC can drive CP radiation. Unlike previously reported PSA elements that have limited CP performance, the proposed PSA-CP configuration adopts additional conductors and ground-via structures to further improve the CP gain, axial-ratio (AR), and cross-polarization (XPD) characteristics. To verify the performance of the proposed PSA-CP, a 2 × 2 left-hand circular polarization (LHCP) sub-array was fabricated at 28 GHz and tested with a BFIC. The measured 10-dB impedance and 3-dB AR bandwidths of the proposed 2 × 2 array were 13.92% and 12.5%, respectively. In addition, the measured peak gain was 15.2 dBic at 28.5 GHz with an XPD level of less than 15 dB.

Wideband Circularly Polarized mm-Wave Array Antenna Using H-Shaped Low-Axial-Ratio Apertures

An H-shaped all-metal radiating element comprising an active and a coupled slot has been proposed to design wideband high-efficiency circularly-polarized antenna arrays. The proper excitation of several modes on the coupled slot enables a wide axial ratio bandwidth with high circular polarization purity. In order to feed an array of such radiating elements, a simple and scalable two-layer corporate network, implemented in groove gap waveguide technology, is conceived. Those good frequency properties have been confirmed by the fabrication of a prototype, whose experimental results report a 1-dB axial ratio bandwidth of 22%. In addition, a peak radiation efficiency of 97% with good pattern stability, and an impedance bandwidth of 21% with high return loss, have been measured. The high circular polarization purity demonstrated by these wideband apertures makes them particularly suitable for Ka-band satellite communications antennas.

Low-RCS Ka-band receiving and transmitting satellite communication antennas co-designed with high-performance absorbent frequency-selective radomes

This paper investigates the low-RCS Ka-band receiving and transmitting satellite communication antennas co-designed with the high-performance absorbent frequency-selective radomes (AFSR). Consisting of the metamaterial absorber (MA) upper layer and bandpass FSS lower layer, two AFSRs operating at 19 and 29 GHz (receiving and transmitting central frequency) with low-frequency wideband absorbing and high-frequency low-insertion-loss transmission performances are proposed. To meet the needs of Ka-band satellite communication, two 4 × 4 microstrip array antennas working at the same central frequencies are co-designed with the AFSRs. We demonstrate the effectiveness of the proposed AFSRs and co-designed antenna through simulations and measurements. The results show that the gain degradations are only 0.44 dB and 0.58 dB at two central frequencies after loading the AFSRs separately, and 10-dB RCS reduction bandwidths are ranging from 6.1–16.3 GHz (relative bandwidth 91.1%) and 10.2–24.8 GHz (relative bandwidth 83.4%) individually.

Broadband Circularly Polarized Magnetoelectric Dipole Antenna and Array for K-Band and Ka-Band Satellite Communications

A circularly polarized (CP) magnetoelectric dipole (ME-dipole) antenna with a wide impedance bandwidth and 3 dB axial ratio (AR) bandwidth is proposed. The antenna is fed by a microstrip line and coupled through a modified cross-slot on the ground plane. Based on the conventional linearly polarized (LP) ME-dipole, the proposed electric dipoles and the coupling slots are modified to generate the CP radiation. Simulated results of the antenna element show an impedance bandwidth of 72.8% from 16.35 to 35.08 GHz and a 3 dB AR bandwidth of 39.2% from 21.53 to 30.07 GHz. To enhance the gain of the antenna for practical application, a 4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 4 antenna array with full-corporate feeding network is designed, fabricated, and measured. The measured results show that an impedance bandwidth of 66.95% from 17.26 to 34.63 GHz and a 3 dB AR bandwidth of 41.1% from 19.25 to 29.25 GHz are achieved. The proposed antenna can be applied to K-band, Ka-band satellite communications or fifth-generation (5G) millimeter wave (mmWave) communications at n257 (26.5–29.5 GHz) and n258 (24.25–27.5 GHz) bands.

Ultra-Low-Profile Continuous Transverse Stub Array for SatCom Applications

Modern K-/Ka-band satellite communications have become increasingly demanding in recent years with regard to the performance of the terminal antenna used in the link. These terminals should be high gain and broadband, as well as guarantee polarization diversity over a large field of view. A low profile is also highly desired to integrate the antenna system into a variety of moving platforms, such as aircraft and trains. An ultra-low-profile continuous transverse stub array is proposed here to tackle these challenges. The antenna array is realized in printed circuit board technology by adopting a contactless transition between the stacked-up layers without resorting to blind or buried vias. The proposed antenna is wideband (impedance matched within the 19–31 GHz band, i.e., ~50%) and provides multibeam radiation for polar angles as far as ±22.5°. The peak value of the gain is 19.7 dBi, and the maximum radiation efficiency equals 50%. Furthermore, the antenna array is combined with a dual-band polarization converter. The latter provides orthogonal circular polarization (CP) in two non-adjacent bands. The overall antenna system performs right- and left-hand CPs within the SatCom downlink and uplink in the K-/Ka-band, respectively. For each polarization, the axial ratio is below 3 dB over 9.47% and 4.42% fractional bandwidths, respectively.

A circularly polarized folded reflectarray antenna for Ka‐band satellite communications uplinks

AbstractA low‐profile circularly polarized folded reflectarray antenna (CPFRA) with linearly polarized (LP) feed antenna is presented in this article. Polarizing grid usually used as the subreflector of traditional FRA is replaced by a polarization‐sensitive frequency selective surface (FSS) in the CPFRA design. The polarization‐sensitive FSS is designed to convert the LP incidence into the CP wave within its passband while reflecting the orthogonal LP incident wave over its operating frequency band. A CPFRA prototype has been proposed and validated for Ka band satellite communications uplinks in this article. The maximum measured antenna gain of 26.0 dBic is achieved at 29.75 GHz with the corresponding antenna aperture efficiency of 40%. Beam scanning property has been achieved by the CPFRA with the mechanical movement of feed horn antenna. All the measured axial ratios (ARs) of the CPFRA are lower than 3 dB in the frequency range from 29 to 30.25 GHz. Meanwhile, the measured antenna gain variation with different beam scanning angles is less than 1 dB from 29.25 to 31 GHz.

Review of Ka-Band Power Amplifier

With the increase in the demand for high-speed transmission communication, satellite communication is developing rapidly. Because of the bandwidth capacity, the K/Ka band is considered the mainstream frequency band of satellite communication. The performance of a power amplifier (PA) directly affects the power of the transmitter, so the application of a power amplifier in Ka-band satellite communication is very important. A review of the state-of-the-art PA in the Ka band is presented in this article. The structure of the PA introduced includes common source, cascode, stacked field-effect transistor (FET), power combining, and Doherty PA, highlighting the advantages and disadvantages. The main solid-state technologies are outlined, including Si, SiGe, GaAs, and GaN, emphasizing Si complementary metal–oxide–semiconductor (CMOS) due to low price and high integration.

3-11 A Measurement of Propagation in High Mobility Environments for Ka Band Satellite Communication

3-11 A Measurement of Propagation in High Mobility Environments for Ka Band Satellite Communication

Evaluation of Ka-Band Rain Attenuation for Satellite Communication in Tropical Regions Through a Measurement of Multiple Antenna Sizes

The Ka-band is modifying the mode of legacy communication towards versatile satellite-oriented systems with the beam-spot capability and a high-throughput architecture to provide twice the capability of classic Fixed Satellite Service (FSS) satellites, thus significantly reducing the cost per bit. Given this background, the contribution of precipitation rate and Ka-band downpour attenuation are expected to improve statistical models for effect prediction. The International Telecommunication Union (ITU) and local researchers are working tirelessly to determine the best prediction model for tropical climates. However, persistent and continuous efforts are required because currently available models do not perform well. The current prediction model for large datasets exhibits a certain deviation. Direct beacon measurement has been compared with an available prediction model that analyses rain effects in tropical regions. Theoretically, the size of the antenna and its gain influence the performance of the receiving signal. Size and availability are two factors which cause degradation and outage in the receiving signal. The majority of extant studies focus on a single antenna with a diameter lesser than 2.4m. Theoretically, antennas with a smaller diameter possess a smaller margin in comparison with antennas with larger diameters. This condition could affect the prediction model when the high attenuation causes a rapid outage in a small antenna and lead to the unavailability of measurement results. To study such effects and provide a good recommendation, the current work measures the beacon attenuation data at two locations, namely, Bukit Jalil (Kuala Lumpur) and Cyberjaya (Selangor). The locations are approximately 15 km apart and have antennas from 0.65m to 31.1m in sizes. Analyses using an available prediction model revealed that ITU-R P.618 provides the lowest RMS value of 14.37 with regards to rainfall rate on two selected samples in Malaysia. High-accuracy prediction can be achieved through the contribution of this study, and comparative data can be obtained for future research. This study is an encouraging step towards a highly comprehensive and accurate prediction of tropospheric impairments in Ka-band satellite communications in the tropical region.

A Scalable Ka-Band 1024-Element Transmit Dual-Circularly-Polarized Planar Phased Array for SATCOM Application

This paper presents a scalable 1024-element transmit dual-circularly-polarized phased array for Ka-band satellite communication (SATCOM) terminal applications. The transmit array based on the CMOS beamformer and a multilayer printed circuit board (PCB) can steer up to large scan angles (±60°) with a scan loss less than 4.5 dB. With the 8-channel transmit beamformer, the array can realize dual circular polarization and the axial ratio (AR) of the array is less than 3 dB in the scanning range of ±30° in both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) mode. The effective isotropic radiated power (EIRP) of the array achieves 74 dBm from 29.5 GHz to 30 GHz. The design and measurement of the 1024-element transmit array have presented a feasible way for mass production of a low cost active phased array.

Dual Circularly Polarized Aperture Array Antenna in Gap Waveguide for High-Efficiency Ka-Band Satellite Communications

This work was supported by the Spanish Ministry of Economy and Competitiveness (Ministerio de Economia y Competitividad) under Project TEC2016-79700-C2-1-R.

A New Broadband Magic Tee Design for Ka-Band Satellite Communications

This letter deals with the design, electromagnetic simulation, and test results of a novel broadband Magic Tee for Ka-band (25.5–27 GHz) satellite communications. Novel matching structure is implemented in the Magic Tee, which results in better electrical performances over broad bandwidth. The designed Magic Tee is realized using electro-discharge machining fabrication technique for achieving stringent dimensional accuracy. The measured bandwidth of the Magic Tee is approximately 16% with a maximum measured in-band insertion loss of 0.2 dB. The simulation results of the developed Magic Tee are compared with measured results using a vector network analyzer showing excellent agreement. The Magic Tee introduced in this letter can be used for designing a monopulse comparator for low earth orbit satellite tracking applications since the amplitude imbalance and phase imbalance of the Magic Tee are negligible, which result in excellent tracking performances.

Dual-Band Dual-Linear-to-Circular Polarization Converter in Transmission Mode Application to &lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$K/Ka$ &lt;/tex-math&gt; &lt;/inline-formula&gt;-Band Satellite Communications

Many wireless communication applications such as satellite communications use circularly polarized (CP) signals, with the requirement for easy switching of the polarization sense between uplink and downlink. Specifically, in satellite communications, the trend is also to move to higher frequencies and integrate the receiving and transmitting antennas in one dual-band terminal. However, these simultaneous demands make the design and fabrication of the composing parts very challenging. We propose, here, a dual-band dual-linear polarization (LP)-to-CP converter that works in the transmission mode. The working principle of this polarizer is explained through an example for Ka-band satellite communications at 19.7–20.2 and 29.5–30 GHz. The LP-to-CP converter is a single panel composed of identical unit cells with a thickness of only 1.05 mm and a size of 5.3 mm $\times5.3$ mm. Due to its operation in the transmission mode, the polarizer can be combined with a simple dual-band dual-LP antenna to obtain the desired dual-band dual-CP single antenna. However, the unique property of this polarizer is yet the fact that it converts a given LP wave, e.g., x-polarization, to orthogonal CP waves at the two nonadjacent frequency bands, e.g., left-handed CP at lower band and right-handed CP at higher band. The polarizer is tested both with 20 and 30 GHz LP rectangular horns to illuminate a dual-band transmit array (TA) to obtain wide-angle steering of CP beams. The performance of the polarizer and its association with the TA is evaluated through simulation and measurements. We also present design guidelines for this type of polarizer.

A Review on Rain Fade and Signal Attenuation by Rain in Ku and Ka Band Satellite Communication at MGC Campus Punjab India

A Review on Rain Fade and Signal Attenuation by Rain in Ku and Ka Band Satellite Communication at MGC Campus Punjab India

0.25-&lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$\mu \text{m}$ &lt;/tex-math&gt; &lt;/inline-formula&gt; BiCMOS System-on-Chip for K-/Ka-Band Satellite Communication Transmit–Receive Active Phased Arrays

The first millimeter-wave system-on-chip for dual-band phased array applications is presented as a proof of concept for K-/Ka-band (20/30 GHz) satellite communication on-the-move applications. Each chip includes four transmit (Tx) and two receive (Rx) channels working at Ka- and K-band, respectively. The proposed architecture enables a half-duplex operating mode in two different bands. Its development was driven taking into account the integration into a realistic Tx/Rx shared aperture phased array architecture. Full amplitude and phase control are provided for each channel with high granularity (65 536 states). The measured results demonstrate the validity of the proposed chip architecture, even though the channel output power and the noise figure (NF) are not in full agreement with the simulations. In Tx mode, the channel provides 9.47 dB of gain with 4.19-dBm output power at 1-dB compression. In Rx mode, the channel gain is 21.6 dB with an NF of 5 dB. In a scenario with 5.265° phase steps and 8-dB amplitude tapering capability, the amplitude and phase root-mean-square (RMS) errors within the Tx bandwidth (29.5–30.8 GHz) are equal to 0.52 dB and 3.74°, respectively. The amplitude and phase RMS errors in the Rx bandwidth (19.7–21 GHz) are equal to 2.05 dB and 12.11°, respectively. The chip consumes 340 mW in Tx and 242 mW in Rx mode and occupies $3.3 \times 3.5$ mm2.

Effects of Atmospheric Impairments of Satellite Link Operating in Ka Band

Over the past decades, satellites have been used to provide a variety of services like voice, data, negation and video. Frequencies above 10 GHz provide new opportunities to meet high bandwidth demands especially for small, maritime, areal and mobile land platforms in order to support beyond line of sight requirements for network centric operations. This is possible due to availability of 1 GHz and more bandwidth. This article discusses about attenuation caused by various atmospheric impairments like rain, cloud, fog, dust etc. at Ka band satellite communications. A new cloud model has been also proposed with comparison of ITU model.

A Ring-Focus Antenna with Splash Plate in Ka-Band

A design for Ka-band satellite communication antenna in earth station is introduced. This kind of antenna uses splash plate feed based on ring-focus antenna. The theory of the new splash plate feed design is presented and the relative equations are derived. The measured antenna parameters, VSWR, and patterns are highly consistent with the simulated results, which demonstrates the success of the design for such kind of antenna that can be effectively used in Ka-band applications.

A low-cost wideband phase shifter for two-way mm-wave phased array antenna system

This paper presents a wideband, low-cost, high-performance, and continuous phase shifter for millimeter-wave (mm-wave) phased array systems. Its operational principle is based on modifying the propagation mode of a grounded coplanar waveguide (GCPW) line by placing a high dielectric constant slab over the GCPW line. The propagation constant and hence the phase shift is varied by changing the air gap height between the GCPW line and the dielectric slab. As a proof of concept, a piezoelectric transducer is used to precisely control this air gap height. A printed circuit board-based phase shifter prototype has been designed, fabricated, and tested at two different frequency bands (19–21 and 28.5–30.5 GHz), which are the downlink and uplink bands, respectively, of the Ka-band two-way satellite communication system. A continuous and almost linear phase–voltage characteristic has been achieved experimentally with average phase shift variations 170° and 260° over the two bands, respectively. The footprint of the proposed phase shifter is 2.1 mm×3 mm, which is quite small and suitable for low-profile mm-wave applications. The average insertion losses over the two bands are &lt;0.53 and 2.35 dB with very low variations±0.22 and ±0.35 dB, respectively.

Data-Aided and Non-Data-Aided SNR Estimators for CPM Signals in Ka-Band Satellite Communications

Adaptive coded and modulation (ACM) is an effective measure to resist rain attenuation in Ka-band satellite communications. The accuracy of the estimator for signal-to-noise ratio (SNR) is one of the main factors that affect ACM performance. This paper establishes the channel model of satellite communication in Ka-band and derives and analyzes data-aided (DA) maximum likelihood (ML) and method-of-moments estimators for SNR of continuous phase modulation (CPM) in Ka-band fading channel. Simulations and analysis indicate that the normalized mean square error (NMSE) of the DA ML estimator is closer to the Cramer-Rao bounds (CRB) at low SNR, but the performance worsens with the SNR increases from medium to high values. The M2M4 estimator performs poorly at low SNR and best at medium SNR. When the SNR is low, the performance of the DA ML estimator is better than the M2M4 estimator; however, the two estimators have similar performance when SNR is high. The performances of the two estimators will become increasingly better the greater the lengths of the observation signals become. However, the influence of the signal length will become increasingly smaller as the SNR becomes larger.