79 research outputs found

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

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    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

    X-Band Dual Circularly Polarized Patch Antenna With High Gain for Small Satellites

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    A hands-on education project: antenna design for inter-CubeSat communications

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    CubeSat platforms have become a de facto standard for universities willing to initiate space-technology activities with students. These small satellite platforms ease the implementation of hands-on education projects and opening the apertures of new research areas. Moreover, due to the limited volume (a 10 cm cube) and power (1 W), the application of imaginative solutions is mandatory. This leads to new innovation processes in the course of CubeSat projects. In this paper, we present a hands-on education project the aim of which is the specification, design, building and measurement of an antenna for communication between nanosatellites and, in particular, CubeSats. The project lies within the framework of ETSIT-UPM innovative education activities in the area of space technology, where students play a leading role in real engineering projects

    Retrodirective phased array antenna for nanosatellites

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    Thesis (M.S.) University of Alaska Fairbanks, 2019This thesis presents a S-band phased array antenna for CubeSat applications. Existing state-of the-art high gain antenna systems are not well suited to the majority of CubeSats, those that fall within the 1U (10 cm x 10 cm x 10 cm) to 3U (10 cm x 10 cm x 30 cm) size ranges and in Low Earth Orbit (LEO). The system presented in this thesis is designed specifically to meet the needs of those satellites. This system is designed to fit on the 1U face (10 cm x 10 cm) of a CubeSat and requires no deployables. The use of beamforming and retrodirective algorithms reduces the pointing requirements of the antenna, easing the strict requirements that high gain antennas typically force on a CubeSat mission. Additionally, this design minimizes volume and uses low cost Commercial-off-the-Shelf (COTS) parts. This thesis discusses the theoretical background of phased array theory and retrodirective algorithms. Analysis are presented that show the characteristics and advantages of retrodirective phased antenna systems. Preliminary trade studies and design analyses show the feasibility and expected performance of a system utilizing existing COTS parts. The preliminary analysis shows that an antenna system can be achieved with ≥8.5 dBi of gain, 27dB of transmitted signal gain, 20% Power Added Efficiency (PAE) within a 1 W to 2 W power output, and an 80° effective beamwidth. Simulation results show an example antenna array that achieves 8.14 dBi of gain and an 82° effective beamwidth. Testing results on a prototype of the front-end electronics show that with minimal calibration, the beamforming and scanning error can be reduced to 5°. The power consumption and signal gain of the electronics is also verified through testing. The CubeSat Communications Platform, a CubeSat mission funded through the Air Force Research Laboratory is in Phase A design to demonstrate this antenna system, along with other experimental payloads. This thesis includes a discussion of interface control, mission requirements, operations, and a recommended experiment sequence to test and verify the antenna system on orbit.Alaska Space Grant Program, NASA Space Technology Research Fellowship (80NSSC170185

    A SIW Based Leaky Wave Antenna for Aerospace Applications in X Band

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    In the rapidly advancing field of aerospace communication and radar systems, the demand for high performance antennas operating in the X-band frequency range has increased significantly. For high speed communication, precise navigation, and accurate detection the antenna in X band is required.  In this paper, the design and analysis of a substrate integrated waveguide (SIW)-based antenna for aerospace applications operating at a frequency of 10.5 GHz. The proposed antenna design integrates the benefits of SIW technology, such as low loss, compact size, and compatibility with planar fabrication techniques, making it suitable for space-constrained aerospace platforms. The antenna had gain of 9.34 dBi, s11 of design is -28.3 at 10.5 GHz. The radiation pattern is approximately omnidirectional

    Küp uydu anten sistemlerinin tasarım, benzetim ve üretimi

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    This study aims to design, simulate, and fabricate on-board and ground station antenna systems for CubeSats, i.e., the most affordable space missions. An on-board UHF turnstile antenna system is optimized in simulation evironment in accordance with different pattern requirements, by changing the orientation of the antenna arms. In order to feed the turnstile antenna arms by successive 90◦ phase differences between them, a four-way quadrature splitter circuit is designed and fabricated. Antenna pattern measurement is conducted in anechoic chamber by connecting the monopole antenna arms to the fabricated power splitter circuit, while the arms are oriented in the optimized directions and placed on a generic 1U CubeSat platform. In addition to the fabricated UHF turnstile antenna, a novel dual-band V/UHF trapped turnstile antenna involving traps on the antenna arms is designed in simulation environment. On the other side, a circularly polarized VHF ground station Yagi antenna system is designed to achieve optimum gain and size, and it is also fabricated by using low-cost materials to be employed for amateur radios. In addition to the radiating metal structure, the VHF Yagi antenna system includes a Wilkinson power divider and impedance matching baluns fabricated by coaxial transmission lines. Besides the reflection coefficient measurements, the constructed ground station antenna system is used for the reception of a Slow Scan TV (SSTV) image broadcasted by International Space Station (ISS) to test its functionality. Finally, as another component of a sub-GHz CubeSat ground station, a circularly polarized UHF Yagi antenna system is designed, based on the experience gained from the VHF ground station antenna design and measurement.Bu çalı¸smada, ula¸sması en kolay uzay platformları olan küp uydular için, araç üstü ve yer istasyonu antenlerinin tasarımı, benzetimi ve üretimi amaçlanmı¸stır. Araç üstü UHF turnike anten sistemi, farklı ı¸sıma örüntüsü gereksinimlerine göre, anten kollarının yönelimlerinin benzetim ortamında degi¸stirilmesiyle en iyile¸stirilmi¸stir. Turnike ˘ anten sistemi elemanlarının aralarında 90◦ faz farkları olacak ¸sekilde beslenmeleri için bir dört yollu, dördün-faz güç bölücü tasarlanmı¸s ve üretilmi¸stir. Üretilen güç bölücüye monopol anten elemanlarının en iyile¸stirilen yönelimlerle 1U ölçüsündeki bir CubeSat platformunun üzerindeyken takılmasıyla, ı¸sıma örüntüsü ölçümleri yankısız odada gerçekle¸stirilmi¸stir. Üretilen ve ölçümü gerçekle¸stirilen UHF bandındaki sistemden ba¸ska, anten kollarında tıkaçlar içeren yenilikçi bir çift-bant V/UHF tıkaçlı anten sistemi tasarlanmı¸stır. Diger tarafta, dairesel polarizasyonlu bir VHF yer istas- ˘ yonu Yagi anten sistemi, en uygun kazanç ve büyüklük hedefiyle tasarlanmı¸s, amatör telsiz kullanımları dogrultusunda dü¸sük bütçeli malzemelerden imal edilmi¸stir. Yayın ˘ yapan metal yapı, e¸s-eksenli iletim hatlarının kullanılmasıyla imal edilen Wilkinson güç bölücü ve empedans uyumlayıcı balunlar vasıtasıyla beslenmi¸stir. Yansıma katsavii yısı ölçümlerinin yanı sıra, Uluslararası Uzay ˙Istasyonu (ISS) tarafından yayınlanan yava¸s taramalı televizyon (SSTV) görüntüsünün üretilen anten yardımıyla alınmasıyla i¸slevsel testler gerçekle¸stirilmi¸stir. Son olarak, VHF anten tasarım ve ölçümlerinden elde edilen tecrübe ile, UHF frekans bandında çalı¸sacak bir Yagi yer istasyonu anten sistemi tasarlanmı¸stır.M.S. - Master of Scienc

    Development of a Nanosatellite Software Defined Radio Communications System

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    Communications systems designed with application-specific integrated circuit (ASIC) technology suffer from one very significant disadvantage - the integrated circuits do not possess the ability of programmability. However, Software Defined Radio’s (SDR’s) integrated with Field Programmable Gate Arrays (FPGA) provide an opportunity to update the communication system on nanosatellites (which are physically difficult to access) due to their capability of performing signal processing in software. SDR signal processing is performed in software on reprogrammable elements such as FPGA’s. Applying this technique to nanosatellite communications systems will optimize the operations of the hardware, and increase the flexibility of the system. In this research a transceiver algorithm for a nanosatellite software defined radio communications is designed. The developed design is capable of modulation of data to transmit information and demodulation of data to receive information. The transceiver algorithm also works at different baud rates. The design implementation was successfully tested with FPGA-based hardware to demonstrate feasibility of the transceiver design with a hardware platform suitable for SDR implementation

    Characteristic Modes Analysis of a Near-Field Polarization-Conversion Metasurface for the Design of a Wideband Circularly Polarized X-Band Antenna

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    A metasurface (MS) based on loop elements operating in the near field of a linearly-polarized microstrip antenna is employed to realize a circularly polarized radiated field. The properties of the loop unit cell are highlighted with the help of the Characteristic Mode Analysis that is employed for investigating the achievable linear to circular polarization conversion bandwidth and providing the guidelines for the design of the final antenna. A finite structure comprising 4×4 unit cells is tailored for achieving a circularly polarized far field within the whole X-band adopted for satellite communications (7.25 GHz-7.75 GHz, 7.9 GHz-8.4 GHz). A simple but effective single-port excitation scheme is adopted, and the overall performance are assessed by measurements on the fabricated prototype. The good agreement between simulated and measured results confirms the reliability of the proposed approach as well as the meaningful insight provided by Characteristic Modes Theory

    Antenna and Random Access Solutions for nano-satellite and 5G networks operating in the millimiter-wave domain

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    L\u2019obiettivo di questa tesi \ue8 la discussione di soluzioni per reti satellitari basate su nano-satelliti e reti 5G, operanti in onde millimetriche. I contributi originali di questo lavoro interessano due settori che ricoprono un ruolo chiave nel contesto delle comunicazioni digitali ad alta velocit\ue0 e alta capacit\ue0: i meccanismi di condivisione del mezzo trasmissivo basati sull\u2019accesso casuale e le antenne a schiera riconfigurabili e compatte. I risultati ottenuti in questi due ambiti sono poi applicati in un\u2019architettura di rete che integra sistemi 5G terrestri e una costellazione di nanosatelliti in orbita bassa. Le comunicazioni satellitari sono sempre pi\uf9 parte integrante della vita quotidiana. Negli ultimi anni, si \ue8 registrata una crescita notevole dei piccoli satelliti (da 1 a 100 kg), sia in termini di tecnologia, che di frequenza di utilizzo. Non solo vengono lanciati in gran numero, ma si \ue8 iniziato ad utilizzarli in costellazioni da diverse decine di unit\ue0. Questa attivit\ue0 \ue8 l\u2019indicatore di una prospettiva ormai prossima: gli sviluppi nel settore dell\u2019Information and Communication Technology hanno avviato diverse iniziative che puntano ad utilizzare megacostellazioni di satelliti come reti per la fornitura di servizi di comunicazione a banda larga. Lo sfruttamento delle onde millimetriche rappresenta quindi un punto cardine per soddisfare la crescente richiesta di capacit\ue0 dei sistemi radio di prossima generazione. Inoltre, lo scenario che ne risulta \ue8 tale da richiedere una connettivit\ue0 completa, cos\uec che ogni satellite operi come un nodo di rete a tutto tondo, con possibilit\ue0 di collegamento tra la terra e lo spazio, e da satellite a satellite. In tale contesto, il ricorso a moderne tecniche di accesso casuale \ue8 particolarmente indicato. Negli ultimi anni si \ue8 assistito a un rinnovato interesse per i protocolli di tipo Aloha, grazie alla possibilit\ue0 di dotare i ricevitori di sistemi di cancellazione dell\u2019interferenza. A tale proposito, viene presentato un nuovo algoritmo che affianca alla cancellazione iterativa di interferenza lo sfruttamento dell\u2019effetto cattura, tenendo al tempo stesso presente la possibile non idealit\ue0 della cancellazione, e quindi la presenza di un residuo. Le sue prestazioni sono confrontate con i metodi attualmente adottati negli standard, mostrando un miglioramento del throughput pari al 31%. Viene inoltre presentata la sintesi di un\u2019antenna a schiera operante in banda Ka adatta per l\u2019uso su nanosatelliti. La schiera risultante offre interessanti benefici in termini di larghezza di banda, polarizzazione e versatilit\ue0, essendo possibile un utilizzo dual-task (downlink verso terra e collegamentointersatellitare). I risultati cos\uec ottenuti sono poi utilizzati per dimostrare, in un simulatore tempo discreto ed evento discreto, le prestazioni ottenibili da un\u2019architettura di rete integrante segmenti di rete radiomobile 5G con una dorsale costituita da una costellazione di nanosatellti. Il simulatore si avvale inoltre di un modello teorico per valutare l\u2019impatto della distribuzione geometrica dei nodi interferenti su una comunicazione in onde millimetriche di tipo line-of-sight. Tale modello, validato con simulazioni di tipo Monte Carlo, contempla i diagrammi di radiazione delle antenne e i recenti modelli di canale in onde millimetriche, che tengono in considerazione rumore, dispersione angolare, fading e bounded path loss. Sono state ricavate delle formulazioni analitiche per la distribuzione della potenza di rumore e interferenza, che consentono di valutare in forma chiusa la probabilit\ue0 di cattura. Tale impostazione \ue8 stata infine usata per discutere gli effetti dell\u2019interferenza sulla capacit\ue0 di Shannon di un collegamento in uplink operante in onde millimetriche, prendendo in considerazione delle condizioni realistiche per il canale

    A Review of Antennas for Picosatellite Applications

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    Cube Satellite (CubeSat) technology is an attractive emerging alternative to conventional satellites in radio astronomy, earth observation, weather forecasting, space research, and communications. Its size, however, poses a more challenging restriction on the circuitry and components as they are expected to be closely spaced and very power efficient. One of the main components that will require careful design for CubeSats is their antennas, as they are needed to be lightweight, small in size, and compact or deployable for larger antennas. This paper presents a review of antennas suitable for picosatellite applications. An overview of the applications of picosatellites will first be explained, prior to a discussion on their antenna requirements. Material and antenna topologies which have been used will be subsequently discussed prior to the presentation of several deployable configurations. Finally, a perspective and future research work on CubeSat antennas will be discussed in the conclusion
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