41 research outputs found

    Design and development of dual-Polarised photovoltaic solar antennae for Ku-band SatComsp.

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    The aim of this thesis is to review the state-of-the-art of transparent patch antennae and to develop design techniques for the experimental development of dual-band, dual-polarised compact transparent patch antennae integrated with solar cells for Ku-band satellite applications. It can be specifically used for Fixed-Satellite-Services (FSS) operating over the frequency range from 11.7 GHz to 12.22 GHz (downlink) and 14.0 GHz to 14.5 GHz (uplink) bands. The research reported in this thesis demonstrated a suspended meshed patch antennae serves as a basic building-block element for a Ku-band dual-polarised transparent array antennae for long distance communications. The results are shown that the use of a suspended patch above a printed radiating patch and ground plane (all transparent) provides dual-band operation for the uplink and downlink. In this work, firstly, a compact low-profile linearly polarised meshed element has been designed, and simulated in CST Microwave Studio electromagnetic simulation software. The photovoltaic antennae element was then fabricated and measured. The comparison between the experimental results and simulation by CST demonstrates good agreement between predicted and practical measurements. The developed antennae element achieved the overall broad bandwidth of more than 1GHz (500 MHz in each of the uplink and downlink bands), and the nominal element gain is 6.055 dBi (downlink) and 7.61 dBi (uplink). A good compromise between the RF performance and the transparency is also obtained with optical transparency of 84% and negligible degradation of the RF performance. The design is then extended to develop a Ku-band photovoltaic antennae element for dualpolarised operation This element could be used for frequency re-use in Ku-band satellite downlink and uplink communicationsin order to double capacity. In addition, the simulation of a 2 x2 sub-array of dual polarised transparent antennae elements (using the experimentally measured performance of the single dual-polarised element) is presented. It has yielded a narrow beam with increased gain of 13 dBi and a cross-polar discrimination of greater than 30 dB is demonstrated, which is a requirement for frequency re-use operation. Hence, the dual-polarised 4-element sub-array described herein could be utilised as the primary building block for a 2D SatCom phased array antennae. In order to meet the full requirements of Kuband SatCom communications employing frequency re-use which essentially doubles the achievable capacity, i.e. two data channels can use the same frequency bands simultaneously using the two orthogonal polarisations with high cross-polar isolation. Using these new designs providing new knowledge in the field of photovoltaic communication antennae at high frequencies, and bridge the associated drawbacks with the current PV antennae

    A compact UWB monopole antenna with penta band notched characteristics

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    A modified rectangular monopole ultra-wideband (UWB) antenna with penta notched frequency bands is presented. An inverted U shaped and slanted U-shaped on the radiating patch are inserted to achieve WiMAX and ARN bands rejection respectively, two mirrored summation Σ-shaped and four mirrored 5-shaped slots are inserted on the partial ground to achieve WLAN and X-band bands rejection respectively, finally rectangular shaped slot with partially open on the feed is inserted to achieve ITU-8 band rejection. The proposed antenna which was simulated has a compact size 30×35×1.6 m3. It is operated with impedance bandwidth 2.8-10.6 GHz at |S11| < −10 dB, that supported UWB bandwidth with filtering the five narrowbands that avoid the possible interference with them. The simulated resonant frequency for notched filters received 3.55, 4.55, 5.53, 7.45, 8.16 GHZ, for WiMAX, ARN, WLAN, X-Band, ITU-8 respectively. The proposed antenna is suitable for wireless communication such as mobile communication and internet of everything (IoE). Throughout this paper, CST-EM software package was used for the design implementation. Surface current distributions for all notched filters were investigated and shown that it is concentrated around the feeding point and the inserted notched slots proving that there is no radiation to the space due to maximum stored electromagnetic energy around each investigated notch slot, proving that the slots play a role of a quarter wavelength transformer which generates for each notched band, maximum gain, and radiation pattern are also investigated

    Integrated Filtering Antennas for Wireless Communications

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    In traditional radio frequency (RF) front-end subsystems, the passive components, such as antennas, filters, power dividers and duplexers, are separately designed and cascaded via the 50 ? interfaces. This traditional approach results in a bulky and heavy RF front-end subsystem, and suffers from compromised efficiency due to the losses in the interconnections and the mismatching problems between different components. The frequency responses of the antennas such as the frequency selectivity and bandwidth are usually degraded, especially for microstrip antennas. To improve the frequency responses and reduce the size of RF front ends, it is important to investigate novel highly integrated antennas which exhibit multiple functions such as radiation, filtering, power dividing and combining or duplexing, simultaneously. In this thesis, several innovative designs of compact, multi-functional integrated an-tennas/arrays are proposed for wireless communication applications. First, new methods of designing integrated filtering antenna elements with broadband or dual-band performance are investigated. These antennas also feature high frequency selectivity and wideband harmonic suppression. Based on these studies, several integrated filtering array antennas with improved gains and frequency responses are developed for the first time. Compared with traditional array antennas, these proposed antennas exhibit improved bandwidths, out-of-band rejection and wideband harmonic suppression. The application of the filtering antennas in millimeter-wave (mm-Wave) frequency band is also investigated as it can potentially reduce the cost of the mm-Wave front-end subsystems significantly while providing the improved impedance bandwidth. The integrated design techniques are further developed to design novel dual-port highly integrated antennas with filtering and duplexing functions integrated. Such a new concept and the prototypes could find poten-tial applications in wireless communication systems and intelligent transportation system (ITS). In this thesis, comprehensive design methodologies and synthesis methods are provid-ed to guide the design of the integrated filtering antennas. The performance is evaluated with the help of full-wave electromagnetics (EM) simulations. All of the prototypes are fabricated and tested for validating the design concepts. Good agreement between the simulation and measurement results is achieved, demonstrating the integrated antennas have the advantages of compact size, flat gain performance, low losses and excellent harmonic suppression performance. These researches are important for modern wireless communication systems

    Ultra Wideband

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    Ultra wideband (UWB) has advanced and merged as a technology, and many more people are aware of the potential for this exciting technology. The current UWB field is changing rapidly with new techniques and ideas where several issues are involved in developing the systems. Among UWB system design, the UWB RF transceiver and UWB antenna are the key components. Recently, a considerable amount of researches has been devoted to the development of the UWB RF transceiver and antenna for its enabling high data transmission rates and low power consumption. Our book attempts to present current and emerging trends in-research and development of UWB systems as well as future expectations

    High Data-Rate, Battery-Free, Active Millimeter-Wave Identification Technologies for Future Integrated Sensing, Tracking, and Communication Systems-On-Chip

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    RÉSUMÉ Pour de nombreuses applications allant de la sécurité, le contrôle d'accès, la surveillance et la gestion de la chaîne d'approvisionnement aux applications biomédicales et d'imagerie parmi tant d'autres, l'identification par radiofréquence (RFID) a énormément influencé notre quotidien. Jusqu'à présent, cette technologie émergente a été la plupart du temps conçue et développé dans les basses fréquences (en dessous de 3 GHz). D’une part, pour des applications où de courte distances (quelques centimètres) et à faible taux de communications de données sont suffisantes (même préférables dans certains cas), la technologie RFID à couplage inductif qui fonctionne à basse fréquences (LF) ou à haute fréquences (HF) fonctionne très bien et elle est largement utilisée dans de nombreuses applications commerciales. D'autre part, afin d’augmenter la distance de communication (quelques mètres), le débit de données de communication, et ainsi minimiser la taille du tag, la technologie RFID fonctionnant dans la bande d’ultra-haute fréquence (UHF) et aux fréquences micro-ondes (par exemple, 2.4 GHz) a récemment attiré beaucoup d'attention dans le milieu de la recherche et le développement. Cependant, dans ces bandes de fréquences, une bande passante disponible restreinte avec la taille du tag assez large (principalement dominée par la taille d'antenne et de la batterie dans le cas d'un tag actif) sont les principaux facteurs qui ont toujours limité l'évolution de la technologie RFID actuelle. En effet, propulser la technologie RFID dans la bande de fréquences à ondes millimétriques briserait les barrières actuelles de la technologie RFID. La technologie d’identification aux fréquences à ondes millimétriques (MMID) offre plus de bande passante, et permet également la miniaturisation de la taille du tag, car à ces bandes de fréquences, la longueur d’onde est de l’ordre de quelques millimètres, une taille comparable à la taille d’un circuit intégré. L'antenne peut donc être soit intégré sur la même puce (antenne sur puce) ou soit encapsulé dans le même boitier que le circuit intégré. En dotant le tag la capacité de récolter sans fil son énergie à partir d'un signal aux fréquences à ondes millimétriques provenant du lecteur, lui fournissant ainsi l'autonomie énergétique (ainsi éliminant la nécessité d'une batterie et en même temps permettant la miniaturisation du tag), il devient alors possible d'intégrer entièrement tout le tag MMID sur une seule puce y compris les antennes, ce qui aboutira à la mise au point d’une nouvelle technologie miniature (μRFID) fonctionnant à la bande de fréquences à ondes millimétriques.----------ABSTRACT For countless applications ranging from security, access control, monitoring, and supply chain management to biomedical and imaging applications among many others, radio frequency identification (RFID) technology has tremendously impacted our daily life. So far, this ever-needed and emerging technology has been mostly designed and developed at low RF frequencies (below 3-GHz). For many practical applications where short-range (few centimeters) and low data-rate communications are sufficient and in some cases even preferable, inductively coupled RFID systems that operate over either low-frequency (LF) or high-frequency (HF) bands have performed quite well and have been widely used for practical and commercial applications. On the other hand, in the quest for a longer communication range (few meters), relatively high data-rate and smaller antenna size RFID systems operating over ultra-high frequency (UHF) and microwave frequency bands (e.g., 2.4-GHz) have recently attracted much attention in the research and development community. However, over these RF bands, a restricted available bandwidth together with an undesired tag size (mainly dominated by its off-chip antenna size and battery in the case of active tag) are the main factors that have been limiting the evolution of today’s RFID technology. Indeed, propelling RFID technology into millimeter-wave frequencies opens up new applications that cannot be made possible today.Millimeter-wave identification (MMID) technology is set out to exploit significantly larger bandwidth and smaller antenna size. Over these frequency bands, an effective wavelength is in the order of a few millimeters, hence close to a typical semiconductor (CMOS) die size. The antenna, therefore, may either be integrated on the same chip (antenna-on-chip – AoC) or embedded in the related package (antenna-in-package – AiP). In addition, by equipping the tag with the capability to wirelessly harvest its energy from an incoming millimeter-wave signal, thereby providing energy autonomy without the need of a battery and at the same time allowing miniaturization, it becomes possible to integrate the entire MMID tag circuitry on a single chip. Furthermore, the timely MMID concept is fully compatible with upcoming and future applications of millimeter-wave technology in wireless communications which are being discussed and developed worldwide in research and development communities, such as the internet of things (IoT), 5G, autonomous mobility, μSmart sensors, automotive RADAR technologies, etc

    Satellite Communications

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    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

    Antenna Designs for 5G/IoT and Space Applications

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    This book is intended to shed some light on recent advances in antenna design for these new emerging applications and identify further research areas in this exciting field of communications technologies. Considering the specificity of the operational environment, e.g., huge distance, moving support (satellite), huge temperature drift, small dimension with respect to the distance, etc, antennas, are the fundamental device allowing to maintain a constant interoperability between ground station and satellite, or different satellites. High gain, stable (in temperature, and time) performances, long lifecycle are some of the requirements that necessitates special attention with respect to standard designs. The chapters of this book discuss various aspects of the above-mentioned list presenting the view of the authors. Some of the contributors are working strictly in the field (space), so they have a very targeted view on the subjects, while others with a more academic background, proposes futuristic solutions. We hope that interested reader, will find a fertile source of information, that combined with their interest/background will allow efficiently exploiting the combination of these two perspectives

    Evanescent-Mode Ridge-Waveguide Radiating Filters for Space Applications

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    [EN] This paper describes a new family of all-metallic radiators based on below-cutoff apertures fed by evanescentmode ridge waveguide filters. The pass band of the filters and the polarization of the apertures are configured to radiate orthogonal signals at different center frequencies. The simultaneous operation of these radiators in an array configuration results in interleaved apertures producing overlapped fields. This strategy reduces the volume and weight of the antenna system, which is a specially appealing characteristic in satellite antennas. Each isolated evanescent-mode filter ends in a small-size aperture and is designed following a novel synthesis procedure. Next, the radiating elements are combined, and the resulting array is analyzed as a multiplexer from the input ports to the freespace region thus accounting for all mutual couplings between different apertures. To validate the theoretical formulations, a prototype has also been manufactured. The results obtained show very good agreement between simulation and measurements in terms of reflection coefficient, side-lobe level and realized gain, thereby fully validating the new family of radiating arrays.This work was supported by the Spanish Ministry of Economics and Competitiveness under Project TEC2016-79700-C2-1-R, Project TEC2016-78028-C3-3-P, Project TEC2013-47037-C5-1-R, and Project TEC2016-75934-C4-1-R.Sánchez-Escuderos, D.; Ruiz-Garnica, J.; Baquero Escudero, M.; Soto Pacheco, P.; Boria Esbert, VE.; Tosso, G.; Angeletti, P.... (2019). Evanescent-Mode Ridge-Waveguide Radiating Filters for Space Applications. IEEE Transactions on Antennas and Propagation. 67(10):6286-6297. https://doi.org/10.1109/TAP.2019.2920272S62866297671

    Antennas for low-cost Ka-band ground terminal devices

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    The ever-growing demand for high-speed data links together with the increasing congestion in the traditional microwave spectrum are pushing for the exploitation of higher microwave and millimeter-wave (mm-wave) frequencies, including the so-called Ka band. Major investments came along, especially in the satellite communications industry, raising the technological con-straints imposed on electronic equipment, mainly concerning performance, compactness and both reduced cost and weight. The great antenna size reduction achieved at Ka band has boosted the research towards satel-lite-on-the-move applications (SOTM), aiming the development of ground terminal antennas for both commercial and personal use. Such antennas must work simultaneously at downlink and uplink Ka bands with circular polarization and also have beam steering capabilities to keep a steady connection with the satellite. In addition, the target is also achieving a cost-effective low-profile antenna. The present thesis is focused on the design of feed antennas to be integrated in mechanical beam steering systems for the aforementioned application. Three different designs are here proposed and discussed. The first one, a wideband ridged horn antenna, was tested standalone and with a dielectric lens antenna. Once good results were achieved in both sce-narios, reducing its height would be the next goal. Thus, the second design is a cavity backed patch antenna. A comparison between both feed antennas is performed, highlighting the pros and cons of both solutions, either standalone or with the same dielectric lens antenna. Here, the first studies with a planar lens antenna are shown. Finally, the third device consists of a ridged cavity antenna with a cross-slot on its top aperture. This time, the feed was successful-ly tested with a transmitarray which allows achieving a more compact antenna system than the first one here presented. This thesis also analyzes two different manufacturing techniques, traditional milling technique and an innovative additive manufacturing (AM) technique based on metallized polymers called stereolithography (SLA). The present AM-SLA prototypes clearly illustrate the strong potential of this technology and pushes for its further assessment

    Étude et réalisation de antennes diélectriques pour les applications satellitaires et corps (BAN)

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    Dans cette thèse, on vise deux types d'applications de l antenne à résonateur diélectrique (DRA): 1) La réalisation d un élément rayonnant pour un réseau phasé embarqué sur un véhicule terrestre ou un avion. Cet élément de base requiert une couverture en élévation supérieure à celle des éléments imprimés pour permettre une poursuite typique comprise entre +-70. La couverture dans un cône large est assurée avec une bonne pureté de polarisation circulaire en alimentant l antenne à travers deux ouvertures à fente en H orthogonales parfaitement découplées en bande X. 2) La deuxième structure est destinée à la diversité d antennes dans le contexte des réseaux corporels embarqués ou Body Area Network (BAN). L antenne à diversité combine une antenne fente en boucle avec un DRA ce qui permet dans un espace compact de réaliser des diagrammes de type broadside et endfire respectivement. Les alimentations considérées sont de 2 types; Soit purement planaire (microruban et coplanaire) soit mixte en combinant une alimentation coaxiale et une alimentation coplanaire. Caractéristiques principales des antennes à résonateur diélectrique (DRA): Pour répondre aux attentes des utilisateurs en termes de débit, les systèmes de communication sans fils se tournent vers des fréquences de plus en plus élevées. La conséquence de cette montée en fréquence est notamment l augmentation des pertes au niveau des éléments conducteurs et donc une diminution de l efficacité globale des systèmes de communication. Dans ces circonstances, les DRA offre de meilleurs résultats par rapport à d'autres familles d'antennes à base d éléments métalliques. De plus, les DRA offrent des pertes diélectriques négligeables, elles sont peu sensibles aux variations de température et s intègrent facilement sur des technologies de fabrication planairesTechnologies such as direct broad cast satellite system (DBSS), Geosynchronous Earth Orbit (GEO) and Low Earth Orbit (LEO) satellite communications , global positioning system (GPS), high accuracy airborne navigation system and a large variety of radar systems demand for high level of antenna performance. Similar is the requirement for upcoming land based wireless systems such as cellular and indoor communication systems that is needed some more specific and additional features added to the antenna to compensate for the deficiencies encountered in system's performance. Though metallic antennas are capable enough to fulfil all the operational requirements, however at very high frequencies and under hostile temperature conditions they are constrained to face certain limitations. To avoid these constraints the performance of Dielectric Resonator Antennas (DRAs) is evaluated and their new applications are proposed. In the thesis, two types of antenna applications are sought :-First is for tracking and satellite applications that needs a larger aperture coverage in elevation plane. This coverage is realized with a good CP purity by proposing two ports dual linearly polarized DRA working at X-band. The DRA is excited by two orthogonal H-shaped aperture slots yielding two orthogonal polarizations in the broadside direction. A common impedance bandwidth of 5.9% and input port isolation of -35 dB are obtained. The broadside radiation patterns are found to be highly symmetric and stable with cross polarization levels -15dB or better over the entire matching frequency band. The maximum measured gain is found to be 2.5dBi at 8.4 GHz.- The 2nd type of antenna is a dual pattern diversity antenna to be used in the Body Area Network (BAN) context. This antenna combines a slot loop and DRA yielding broadside and end-fire radiation patterns respectively. Based upon the feeding techniques, the DG antenna is further divided into two categories one with planar feeds and the other with non-planar feeds (slot loop excited by planar CPW but DRA excited by vertical monopole) .Both types are successfully designed and measured upon body when configured into different propagation scenarios. The non-planar feeds antenna allows wider common impedance bandwidths than the planar feeds (4.95% vs 1.5%).In both cases, a maximum value of DG=9.5dB was achieved when diversity performance tests were carried out in rich fading environments. This value is close to the one (10 dB) theoretically reached in a pure Rayleigh environment and was obtained with efficiencies of 70% and 85% for the slot loop and the DRA respectively. Therefore, we conclude that these antennas could be used on the shoulders or the chest of professional clothes (firemen, policemen, soldier) where full planar integration is not a key issue but where the communication must be efficient in harsh environments and for various gestures, positions and scenariosPARIS-EST-Université (770839901) / SudocSudocFranceF
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