Design and Prototype of a Phased-Array Antenna for Nanosatellite Radar and Communication Applications

Reconfigurable software defined radios are capable of altering radio frequency parameters of a transceiver to add functionality and improve performance. Initially static by design, reconfigurable radios have become common on nanosatellites, assisting in reduction of launch costs and addition of functionality. Antenna designs have also become reconfigurable, by being able to change frequency range, polarization and many other characteristics. Some antenna designs also perform lobe (beam) steering; however, they are not commercially available for nanosatellites. Some of the added benefits of beam steering are debris detection and satellite-to-satellite communication. Therefore, this research combines antenna frequency reconfigurability and beam steering using an array to design an antenna that can be mounted on a nanosatellite

低地球軌道コンステレーションの追跡のための適応アンテナアレイ実装のシミュレーション

Since Low Earth Orbit has become an in orbit to place satellites, CubeSat constellation tracking is challenging. Higher capacity and capability of a new Ground Station tracking system are in demand and this, motivates researchers to come out with a solution to mitigate the traditional Ground Station degradation performance. This paper discusses the Least Mean Square algorithm\u27s implementation in Adaptive Array Antenna for the Ground Station tracking system application. The simulation results show the capability of the main beam pattern to perform instantaneous tracking and steering towards the targeted CubeSat while suppressing the side lobes towards the other interfering CubeSats when a massive CubeSats constellation take place. Planar and circular array antennas are analyzed by setting the optimum weighting factors to be adapted. Three scenarios of CubeSats constellations are simulated. The performance of the Adaptive Array Antenna for each scenario is analyzed based on the beam width characteristics and the Signal-to-Interference Ratio of the beam pattern. The number of CubeSats tracked by the Adaptive Array Antenna and the capability of the system to perform fast-tracking as the number of antenna array elements is increased also discussed in this paper. Finally, solutions to mitigate the limitation of the Least Mean Square algorithm to perform fast-tracking when massive interferer CubeSats are nearby are proposed.九州工業大学博士学位論文 学位記番号：工博甲第507号 学位授与年月日：令和2年9月25日1 INTRODUCTION|2 THEORETICAL BACKGROUND AND LITERATURE REVIEW|3 RESEARCH METHODOLOGY|4 RESULTS AND DISCUSSION|5 CONCLUSION AND RECOMMENDATION九州工業大学令和2年

Smart Adaptive Beam-Forming Antenna Design for Next Generation Communication Systems

Adaptive beamforming antennas open a new venue for research to achieve high data rates. Such antennas are of interest at higher frequencies, especially at millimeter-waves. Millimeter-wave band ranges from 30 GHz - 300 GHz. There is an ample bandwidth available in this spectrum. However, due to the significant path loss at high frequencies, there is a need for better error correction schemes and adaptive beam-forming antennas for this frequency band. The goal of our research is to design a novel adaptive beamforming smart antenna that is low cost, compact, power-efficient and less complex. Based on our recently awarded US patent, we have devised a novel beamforming technique in which phased array and parasitic array approaches are used in conjunction with each other. Conventionally, phased array or switched array techniques are used in smart antennas for beam-steering. In phased array antennas each antenna element has a separate excitation. Therefore, such antennas are costly and impractical for use in everyday communication devices. Switched array antennas are cost-effective and simple to implement, but the antenna beam can only be formed at a predefined location. Our proposed novel beamforming technique is based on a mathematical model. After mathematical modeling, the antenna is simulated in Ansoft High Frequency Structure Simulator (HFSS). Results of the simulated model in Ansoft HFSS and the mathematical model are in close agreement with each other, Ansoft HFSS uses the finite element method (FEM) for complex electromagnetic computations. Antenna design consists of two circular arrays of six parasitic elements. Each array has an active element in its center and there is a fixed phase difference between excitation currents to the active elements. The beam is steered either by changing the phase difference between excitation currents to the active elements or by changing reactance of the parasitic elements. Our technique is novel as this is the first time switched parasitic array and phased array approaches are efficiently used in conjunction with each other. After mathematical modeling and simulations, two antennas are designed and tested. The first antenna is centered at 2.5 GHz. This antenna is used for proof of concept. The second antenna is centered at 28 GHz. The 28 GHz band will play a key role in the next generation of wireless networks, i.e., 5G. The antenna hardware testing results are also in line with the mathematical and the simulated models. This dissertation aims to provide an overview of smart adaptive beamforming antenna design, propose a mathematical model for novel hybrid beamforming, present the application of the proposed antenna in satellite communication and airborne communication, and demonstrate the validity of the design via software simulations and hardware testing

Technology for large space systems: A special bibliography with indexes (supplement 04)

This bibliography lists 259 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1980 and December 31, 1980. Its purpose is to provide information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology Program. Subject matter is grouped according to systems, interactive analysis and design. Structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, solar power satellite systems, and flight experiments

Implementation of Adaptive Antenna Array for Ground Station Tracking System

As the number of small satellites keeps increasing due to the low-cost development and fast delivery duration, there is a demand for higher capacity and capability of the ground station tracking system. Generally, the existing ground station tracking system faces major performance degradation while tracking satellites because of signals interference and multi-path fading. These problems motivate researchers to come out with interesting solution to mitigate the degradation performance. This paper describes the implementation of adaptive beam forming algorithm of phased array antenna for ground station tracking system. The adaptive antenna array demonstrates electronically self-steering radiation pattern capability towards satellites signals, suppress interferences and multi-path signals. This can be achieved by adapting the Least Mean Square (LMS) algorithm by varying the number and phase of the array antenna elements and the angle of beam steering to determine the Direction of Arrival (DOA) of incoming signals. The performance of adaptive LMS algorithm is investigated in MATLAB software by analyzing the radiation patterns for different number of array antenna elements, phases and beam steering angle. The purpose of LMS algorithm implementation in the Adaptive Array Antenna (AAA) system is to control weights adaptively, optimize the Signal to Noise Ratio (SNR) of the desired signal and minimize the Mean Square Error (MSE).32nd International Symposium on Space Technology and Science, June 15-21, 2019, Fukui, Japa

Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

Satellite Communications

This study is motivated by the need to give the reader a broad view of the developments, key concepts, and technologies related to information society evolution, with a focus on the wireless communications and geoinformation technologies and their role in the environment. Giving perspective, it aims at assisting people active in the industry, the public sector, and Earth science fields as well, by providing a base for their continued work and thinking

Crowded space: a review on radar measurements for space debris monitoring and tracking

Space debris monitoring is nowadays a priority for worldwide space agencies, due to the serious threat that these objects present. More and more efforts have been made to extend the network of available radar systems devoted to the control of space. A meticulous review has been done in this paper, in order to find and classify the considerable amounts of data provided by the scientific community that deal with RADAR measurement for the debris monitoring and tracking. The information gathered is organized based on the volume of found data and classified taking into account the geographical location of the facilities