Fixed Satellite Service Research Articles

Modeling of Fixed Service Interference in Aeronautical SATCOM Channels

A detailed assessment of the radiofrequency interference from terrestrial fixed service into aeronautical earth stations operating with geostationary satellite orbit networks in the fixed-satellite service is performed. We analyze the impact of the major physical, technical, operational, and regulatory parameters in the interference environment having multiple degrees of freedom to be considered. By performing exhaustive geometric computer simulations, we determine the statistical characteristics of the time-variant radiofrequency interference caused by multiple terrestrial fixed service transmitters using information of existing/registered fixed service stations in France. Subsequently, a stochastic channel model to predict the impact of the terrestrial interference using a higher order finite-state Markov process is developed. Balancing model accuracy and complexity, a reasonable vector quantization clustering algorithm is applied for the partitioning of the interference into representative channel states. For these channel states, we provide a method for scaling this model to different antenna sizes and flight velocities, to be used for development of interference mitigation measures and system design of aeronautical earth stations in motion operating in the 17.7–19.7 GHz frequency range.

Hybrid of Angular and Distance Protection for Coexistence of 5G Base Stations and Satellite Earth Stations

In this study, we investigated the coexistence of the 5G communication network with a fixed-satellite service (FSS) in the 3.5 GHz and 26 GHz frequency bands. We analyzed an angular protection scheme for the FSS Earth station (ES) and 5G base stations (BSs). In addition, we defined the fixed BS-ES relative location, relative distance, and angular changes. The angular protection was integrated into the exclusion and restricted zones proposed by the distance protection scheme for simulation analysis to develop a transmit power control scheme based on the Citizens Broadband Radio Service. Its performances were extensively analyzed through simulations. The proposed scheme was evaluated in practical scenarios: rural macrocells, urban macrocells, and urban microcells, as defined by the 3rd Generation Partnership Project (3GPP). The influence of antenna type was also researched, and BSs with 4 × 4, 8 × 8 and 16 × 16 antenna arrays, as specified by 3GPP, were considered for 5G networks. Finally, the results prove that the angular protection solution can solve the coexistence of the 5G system and the FSS. In addition, when angular protection and distance protection are used simultaneously, the coexistence effect of the two systems can be strengthened. Moreover, this work provides a quantitative perception for selecting system parameters, including an interference margin for the different scenarios and antenna types, the exclusion size, and the reduction area.

High gain wide band grid array antenna for short range radar and vehicle-to-satellite communications

This paper presents the design of a Grid Array Antenna that covers both Short Range Radar applications at 24 GHz, the spectrum requirement of Ku-band transmit mode for Fixed Satellite Service and Direct Broadcast Service for Vehicle to Satellite communications. The proposed Grid Array Antenna design has vertical short radiating wire segments and long radiating wire segments loaded with parallel reactive disc structures to enhance the bandwidth. Taylor synthesis method of amplitude-tapering reduces the Side Lobe Level to −16.3 dB. The simulation and measurement results are in alignment with each other covering the bandwidth of 12.58 GHz (VSWR ≤ 2), Half Power Beam Width of 7.8° in E-plane, and 101.6° in H-plane at 24 GHz and broadside radiation for Vehicle-to-Satellite communication. The antenna parameters are analyzed for housing effect and mounted on a virtual model of a vehicle. The aforementioned results show that the proposed antenna is well suited for the spectral coverage of Vehicle-to-Satellite communication, Blind Spot Detection, and pre-impact sensing in Short Range Radar automotive communication.

A notched UWB microstrip patch antenna for 5G lower and FSS bands

AbstractIn ASEAN countries, the fifth generation (5G) forum proposed a 5G application lower frequency band (4.5–5.5) GHz and the fixed satellite service (FSS) C‐band at (3.3–4.2) GHz. Previous research works have demonstrated that the complexity of antenna design, large size and in most of the cases, active elements that were added to antenna has made the antenna costly. Therefore, this research work focused on developing a single band notched (SBN) and double band notched (DBN) antennas by creating notched bands for 5G lower band from 4.5 to 5.5 GHz and C‐band 3.3 to 4.2 GHz applications in antenna UWB spectrum. An UWB antenna has been developed using low‐cost FR‐4 substrate with partial grounding (PG) on a rectangular patch. A single band and dual band notched UWB antennas were realized for the 5G lower band through the use of a slot at the top of the radiating patch and by adding an arc shape open loop (ASOL) on the UWB antenna. Both antennas are fabricated using the same FR‐4 substrate and tested using Vector Network Analyzer (VNA). The voltage standing wave ratio (VSWR), return loss, gain, and 2‐D radiation pattern of the test results prove that all antennas have excellent performance (compared to previous research works) in notched band and UWB band frequencies. Therefore, developed single notch and dual notch UWB antennas are proposed as good candidates for 5G lower band and C‐band notched application environment.

Coexistence of Satellite Ground Stations in Teleport Facilities: Interference Assessment, Real Application Scenario and Measurements.

This article introduces a unified and detailed methodology for interference assessment between coexisting fixed satellite service (FSS) and broadcast satellite service (BSS) with spectrum sharing at the Ka-band. The interference analysis is presented along with a step-by-step algorithm for the calculation of the carrier-to-interference ratio (CIR). The proposed procedure takes into consideration the near-field effect of ground-satellite-terminal antennas since these may reside at very close distances. Furthermore, numerical results are delivered so as to assess the CIR in relation to the relative geometry and the technical characteristics of the satellite terminals. A real application scenario is also provided along with measurements so as to validate the recommended methodology. Finally, mitigation techniques are proposed for the protection of the victim stations and operation under harmful interference conditions.

Starlinked! An analysis of SpaceX’s small satellite mega-constellation under the Fourth Amendment

ABSTRACT Private commercialization is making broadband internet accessible through a new frontier: space. Space Exploration Holdings, LLC (SpaceX), is launching a mega-constellation of thousands of small-satellites into low-Earth orbit to provide fixed-satellite service across the globe. In order to do so, SpaceX was required to receive a license from the Federal Communications Commission (FCC). The licensing regime is part of a larger international regulatory framework based on five governing treaties – the Outer Space Treaty, Rescue Agreement, Liability Convention, Registration Convention, and the Moon Treaty. Compliance with these treaties is managed through the International Telecommunications Union (ITU) an agency of the United Nations. In this instance, the FCC’s domestic licensing processes ensure compliance by the United States to the ITU’s procedures and the treaties. The role of the FCC in maintaining these regulatory operations may, however, introduce risks to consumer privacy. This paper explores the tension between government regulation of information and communication technologies, specifically, small satellite mega-constellations and the right to privacy under the Fourth Amendment of the United States Constitution.

Flexible ku/k band frequency reconfigurable bandpass filter

<abstract> <p>The proposed reconfigurable BPF satisfies the International Telecommunication Unionos (ITU) region 3 spectrum requirement. In transmit mode, the frequency range 11.41-12.92 GHz is used by the direct broadcast service (DBS) and the fixed satellite service (FSS). Direct broadcast service (DBS) in reception mode employs 11.7-12.2 GHz and 17.3-17.8 GHz frequency ranges. Frequency reconfigurable filters are popular because they can cover wide range of frequencies, reducing system cost and space. Another emerging trend is electronic component flexibility or conformability, which allows them to be mounted on non-planar objects and are used in wearable applications. This project contains a frequency-reconfigurable BPF that has been entirely printed on a flexible polimide substrate. Frequency reconfigurability is obtained by using a pin diode HSCH 5318 and it is used to switch between 12 GHz and 18 GHz. The prototype reconfigurable BPF is highly compact and low-cost due to the flexible polimide substrate and the measured results are promising and match the simulated results well.</p> </abstract>

Parametric Analysis of the Defected Ground Structure-Based Hairpin Band Pass Filter for VSAT System on Chip Applications

In this study, a three-pole hairpin structure was fabricated on the top of the substrate material and an open loop microstrip structure at the ground to give a modified triple-band BPF with a unique design. A Rogers (RT5880) material with εr = 2.2 and thickness of 1.27mm was used to fabricate the proposed structure. The space between two consecutive hairpin resonators has different distances d1 and d2 with values of 0.2mm and 0.4mm respectively. The proposed filter offers a compact size with low return loss. The equivalent LC circuit of the DGS and hairpin structure is obtained with the Ansys electronic desktop and by using simple circuit analysis. The desired microstrip triple-band BPF operates at the Ku band, resonates at 10.28GHz, 12GHz, and 14.62GHz, while the simulated and experimental results are almost identical. The proposed wideband BPF satisfies the International Telecommunication Union ((ITU) region 3 spectrum requirements. Direct Broadcast Service (DBS) and Fixed Satellite Service (FSS) in transmit mode respectively employ the frequency band 11.41-12.92GHz and 14-14.5GHz.

Assessment of Antenna Mounting Building Structural Strength using Microtremor Analysis

Any satellite tracking ground station requires fully steerable dish shaped antenna for fixed satellite services. Antenna foundations require special consideration, because they transmit dynamic loads to soil and foundation system, in addition to static loads due to self-weight of foundation, antenna and its accessories. Antenna foundations are of ground foundation or roof top i.e on buildings based on Radio Frequency requirements. To install antennas on existing building, the building should have required strength. To assess the building strength, building natural frequency and damping ratios are determined using Microtremor recorded data. For rotating Antennas, the required building frequency should be more than 8 Hz to avoid resonance effect of antenna structure natural frequency with servo frequency. In this study, the data is collected for building located at National Remote Sensing Centre, ISRO, Shadnagar, Hyderabad by mounting sensor at 3 locations of building. The data collected is analyzed using View 2002 software. FFT analysis is carried out to identify predominant natural modes and frequencies of the Building.

Distance Protection for Coexistence of 5G Base Station and Satellite Earth Station

In this paper, we investigate the coexistence of the 5G communication network with a fixed-satellite service (FSS) in the 3.5 GHz and 26 GHz frequency bands. We analyze a distance protection scheme for the FSS Earth station (ES) and 5G base stations (BS). Furthermore, we define the exclusion and restriction zones to develop a transmit power control scheme based on the Citizens Broadband Radio Service (CBRS). An interactive power control scheme is also devised for the restriction zone and extensively analyzed through simulations. The proposed scheme is examined for practical scenarios such as the rural macrocells (RMa), urban macrocells (UMa), and urban microcells (UMi) as defined by the 3GPP. The impact of the antenna type is also investigated, and BSs with omnidirectional, 4 × 4, 8 × 8, and 16 × 16 antenna arrays are examined, as defined by 3GPP, for the 5G networks. The results confirm that 5G systems can coexist with the FSS and provide quantitative insights into the selection of the system parameters, including interference margins, exclusion sizes, and reduction zones, for different scenarios and antenna types.

A CPW fed monopole antenna for UWB/KU band applications

A Co-planar Waveguide fed antenna for KU and wide band applications is designed and presented. The antenna is of size 24 × 25 × 1.52 mm3 with an incised rectangular patch on a TLY-5A substrate with permittivity 2.17 and loss tangent of 0.0009 is presented. The proposed antenna has the operational bandwidth from 3.11 GHz to 18.03 GHz covering the UWB band (3.1–10.6 GHz) and KU band applications. The UWB finds applications in networks working under wireless devices along with image sensing systems that utilizes the broad range advantages whereas some key KU band applications include Fixed Satellite Service (FSS from 11.7 to 12.7 GHz) and Direct Satellite Service (DBS from 12.2 to 12.7 GHz). The UWB characteristics are obtained by introducing the circular incisions on the rectangular patch whereas the KU band characteristics are obtained by changing the center position of the circular incisions as well as changing the dimensions of the ground. The simulated results of return loss, VSWR, impedance characteristics, current distribution, and radiation pattern are obtained using Ansys HFSS version 16.2 on designing the proposed antenna. The antenna also has additional advantages: compact size along with stable gain and radiation patterns when compared with antennas having similar functions. An evolutionary process performed to get an optimized design for good impedance matching across the bandwidth and desired output.

On the design of novel half T-square strip fractal antenna

ABSTRACT In this paper, a novel half T-square strip fractal antenna has been proposed. The antenna has been designed on FR4 (ɛr = 4.4) substrate with a size of 26 × 20 × 1 mm. The reported antenna resonates at 0.91 (0.89–0.95 GHz), 2.16 GHz (2.1–2.23 GHz), 4.19 GHz (3.9–4.4 GHz), 5.22 GHz (5.1–5.3 GHz), 7.69 GHz (7.3–8 GHz), and at 9.16 GHz (9.1–9.3 GHz) having a gain of 5.6 dB, 0.2 dB, 1.4 dB, 2.1 dB, 2.4 dB, and 2.5 dB, respectively. The antenna size has been miniaturised by 93% in terms of the lowest resonating frequency in comparison to a conventional patch antenna by using fractal geometry. The proposed antenna covers the frequency bands for applications such as Radiolocation, deep space research, Aeronautical Radio Navigation services (ARNS), Maritime Radio Navigation services (MRNS), and Fixed Satellite Services (FSS). The prototype of the proposed half T-square strip fractal antenna has been fabricated. The measured and simulated results are in good agreement.

Adjacent channel compatibility between IMT and ubiquitous FSS Earth Stations in the 3.4–3.8 GHz frequency band

This study has investigated the mitigations necessary for successful compatibility between International Mobile Telecommunications (IMT) services and Fixed Satellite Service (FSS) Earth Stations operating in adjacent frequency bands. We consider a problem where IMT services operate in the 3.4–3.6 GHz frequency band and FSS Earth Stations operate in the adjacent 3.6–3.8 GHz band (both bands are within the frequency range designated C-band). The results presented in this paper are applicable to other boundaries between IMT and FSS operating in C-band. This is an adjacent band compatibility problem, hence the mitigation considered is based on frequency separation. We firstly perform a co-frequency interference analysis and then determine the Net Filter Discrimination available for a range of possible frequency separations including Guard Bands. These calculations rest on some assumptions regarding the IMT transmitter and FSS receiver spectrum masks. We present some results which show that an 18 MHz Guard Band is sufficient to mitigate interference. This analysis is based on the median aggregate interference-to-noise ratio $$\Sigma I/N$$ delivered by our co-frequency analysis, using a − 10 dB threshold and covering all of the spectrum mask combinations considered in the study.

Impact of 5G New Radio Downlink Signal on Fixed-Satellite Service Earth Station

Impact of 5G New Radio Downlink Signal on Fixed-Satellite Service Earth Station

A Compact CPW-Fed Planar Stacked Circle Patch Antenna for Wideband Applications

The article investigates the performance of planar and compact CPW-fed microstrip patch antenna that offers 10 dB impedance bandwidth over the wide frequency range between 2.59 and 7.61 GHz. The parametric analysis of various design variables is included to acquire the final design of proposed antenna. The prototype exemplary of designed antenna is experimentally tested to obtain the return loss, VSWR, radiation response and gain characteristics. The close agreement is acquired between simulated and experimental results.The projected antenna has compact size of 0.61λ0 × 0.44λ0 × 0.027λ0 mm3 and offers a 10 dB wide impedance bandwidth of 5.02 GHz. Thus, it may be considered suitable for variety of wireless applications including WLAN, Wi-MAX, fixed satellite services, wireless point-to-point applications etc.

A compact flower slotted dual band notched ultrawideband antenna integrated with Ku band for ultrawideband, medical, direct broadcast service, and fixed satellite service applications

AbstractA compact flower slotted antenna (FSA) for dual band eliminated ultrawideband (UWB) integrated with Ku band applications is proposed. The basic FSA with modified ground structure is utilized for obtaining fractional bandwidth of 137% (3.45‐18.45 GHz). The dual band eliminated frequencies are achieved by a via hole to eliminate 5.39 to 5.90 GHz (upper WLAN band) frequencies and by utilizing symmetrical inverted L‐shaped parasitic elements to notch 7.30 to 7.75 GHz (downlink of X‐ band satellite communication link) frequencies. The FSA is having a compact size of 16 × 22 mm2 printed on low cost FR‐ 4 substrate with two band notched characteristics, nearly omnidirectional radiation characteristics and stable gain over UWB frequency range makes it suitable for portable UWB systems.

Multiband planar antenna with CSRR loaded ground plane for WLAN and fixed satellite service applications

Abstract In this paper, a novel approach to achieve multiband antenna operation using metamaterial based resonant structures is presented. Multiband antenna operation is achieved by employment of complementary split ring resonators (CSRR) printed in the ground plane. The CSRRs resonate at different frequencies according to their optimized dimensions. Proposed approach features simple design and fabrication possibility compared to other methods of achieving multiband antenna operation such as usage of composite right/left-handed (CRLH) transmission line or split ring resonators (SRR) or CSRR around the patch surface. The proposed method is demonstrated through simulation and experimental measurements using three CSRRs with different resonant frequencies together with a tuning CSRR and a radiating patch. Contribution of different CSRRs to obtain multiple resonances have been shown by surface current plots. Measured antenna gain of 2.78, 1.27 and 3.45 dB has been obtained at frequencies of 5.25, 6.28 and 7.29 GHz respectively. The measurements done on developed antenna exhibits close agreement with the simulation results. In context with the current communication application trends involving multiple operating bands like 5G, this approach may have immense application potential since the same can be adopted to achieve compact multiband antennae operation in other frequency bands of interest.

A novel bandwidth enhanced triple band antenna for satellite and airborne applications

<p align="justify"><span>This paper presents a novel bandwidth enhancement technique in which a passive stack of third order Sierpinski carpet fractal antenna is parasitically coupled to the driven element that is also a Sierpinski fractal of third order. Edge feeding technique is used. The passive stack placed symmetric to the driven elements provide the combined benefits of horizontal and vertical parasitic coupling, with added advantage of miniaturization contributed by fractal technology. Result of the study indicate that the antenna array provide triple band with a large inter-band separation that mitigates the effects of inter-band interference. The first band at 6.1Ghz with bandwidth of 250Mhz supports mobile wireless and fixed satellite service, the second band at 7.1Ghz with 350Mhz bandwidth supports mobile wireless, fixed wireless and fixed satellite service. The third band is at 11.6Ghz with bandwidth of 1.4Ghz and supports fixed wireless and fixed satellite services. The number of elements in the parasitic stack influence array performance in terms of bandwidth, gain and directivity. The bandwidth in the third band increased from 1.5Ghz for two-element stack to 1.7Ghz for three-element. This has an advantage over conventional antenna array, that use more active antenna elements that have the limitations of more power consumption and large space occupancy. </span></p>

High-Efficiency, Wideband GRIN Lenses With Intrinsically Matched Unit Cells

We present an automated design procedure for the rapid realization of wideband millimeter-wave lens antennas. The design method is based upon the creation of a library of matched unit-cells which comprise wideband impedance matching sections on either side of a phase-delaying core section. The phase accumulation and impedance match of each unit-cell is characterized over frequency and incident angle. The lens is divided into rings, each of which is assigned an optimal unit-cell based on incident angle and required local phase correction given that the lens must collimate the incident wavefront. A unit-cell library for a given realizable permittivity range, lens thickness, and unit-cell stack-up can be used to design a wide variety of flat wideband lenses for various diameters, feed elements, and focal distances. A demonstration GRIN lens antenna is designed, fabricated, and measured in both far-field and near-field chambers. The antenna functions as intended from 14 GHz to 40 GHz and is therefore suitable for all proposed 5G MMW bands, Ku- and Ka-band fixed satellite services. The use of intrinsically matched unit-cells results in aperture efficiency ranging from 31% to 72% over the 2.9:1 bandwidth which is the highest aperture efficiency demonstrated across such a wide operating band.

Interference Mitigation using Adaptive Beamforming with RLS Algorithm for Coexistence between 5G and Fixed Satellite Services in C-Band

Smart antenna system is one of the most suitable techniques making the sharing between incumbent Fixed Satellite Services (FSS) and the Fifth Telecommunication Generation (5G) possible, because adaptive beamforming can make null the beam towards the FSS earth station. This paper proposes the use of Recursive Least Square (RLS) algorithm for adaptive beamforming in 5G Base Station (BS) having a null beam toward FSS earth station. We perform a computer simulation to evaluate the proposed RLS algorithm and compare the result in terms of separation distance between FSS earth station and 5G BS with and without RLS algorithm. The results confirmed that the RLS algorithm for adaptive beamforming makes the coexistence between 5G and FSS possible indicated by the significant reduction of separation distance between FSS earth station and 5G BS leading to the minimum interference of 5G BS to the FSS earth station.