2 research outputs found

    Wireless Applications of Radio Frequency Micro-Electro-Mechanical Systems

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    With mass proliferation of wireless communication technologies, there is a continuous demand on fast data transmission rate and efficient use of frequency spectrum. As a result, reconfigurable systems are of significant importance and research is being conducted in numerous universities. The purpose of this research is to develop novel RF MEMS based reconfigurable wireless systems. By utilizing the RF MEMS switches as a basic building block, this thesis focus on developing a unique design technique for the design and development of RF MEMS delay line phase shifter, frequency reconfigurable antennas and pattern reconfigurable antennas. This thesis work is divided into four parts: 1. Investigation and development of nano-electro-mechanical systems (NEMS) based 3-bit phase shifter. Analyzing the slow wave structure to further reduce the size of delay line phase shifter. 2. Development of frequency reconfigurable antennas to compete with broadband and multi-band antennas. Two novel MEMS-loaded frequency reconfigurable antennas were designed with spectrum switchable between WPAN band (57 to 66 GHz) and the whole E-band (71 to 86 GHz). 3. Investigation of microstrip-to-coplanar striplines (CPS) transition balun used for antennas to explain the inherent phase delay of this type of structure. Based on the discovery, a pattern reconfigurable quasi-Yagi antenna was designed. The antenna exhibits excellent RF performance, compact size and switchable end-fire radiation pattern with the goal to replacing existing phased array antennas. It has the full functionality of a multi-antenna phased array plus phase shifting network while its size is same as a fixed single Yagi antenna. 4. Development of full seven masks all metal fabrication process of the RF MEMS integrated reconfigurable antennas. The fabrication processes are optimized based on Australian National Fabrication Facility (ANFF) New South Wales node’s equipment

    Architectures multi-bandes en mode impulsionnel et circuits pour des applications nomades très haut débit autour de 60GHz

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    Avec la croissance actuelle du marché des applications de transfert de données multimédia à très haut débit, les bandes de fréquences autour de 60 GHz sont une nouvelle alternative promettant des performances intéressantes en terme de débits mais soulèvent des défis techniques et technologiques au niveau des architectures et circuits. C'est dans ce cadre que s'inscrit cette thèse, qui propose une approche multi bande impulsionnelle MBOOK avec un récepteur à détection d'énergie, et qui analyse plus spécifiquement les verrous au niveau de l'émetteur. L'étude du canal de propagation à 60 GHz, basée sur les modèles de canaux du standard IEEE 802.15.3c, a permis de démontrer la potentialité de cette architecture et permet d'atteindre des débits de 2 Gbps à 2metres dans un environnement de type résidentiel. Le dimensionnement de l'architecture ainsi que des performances des principaux blocs ont conduit à plusieurs possibilités pour l'architecture de l'émetteur MBOOK à 60 GHz. Les critères ont été d'assurer un compromis performances, consommation. Une étude approfondie sur l'étude des imperfections de certains blocs critiques et l'impact sur l'impulsion transmise, et donc sur les performances du système ont été établies. Le banc de filtres, nécessaire à l'émission et à la réception, représente l'un des verrous, et nous proposons une solution de filtrage à base de lignes couplées. L'étude des solutions de génération d'impulsions, des étages de commutation, et des étages d'amplification de l'émetteur sont détaillées et discutées dans les deux derniers chapitresWith the current increasing market request concerning high speed data rates applications, the 60 GHz frequency bands seems to be one of the new promising alternatives for high data rate wireless communications. In this context, the development of new systems operating at these frequencies becomes a very attractive research subject. This study focuses on nomadic systems offering high data and reconfigurable rates, low complexity, low power consumption for short communications. One of the important tasks in the millimetre wave architecture design is to consider the channel propagation characteristics simultaneously with the technological performance of integrated circuits and antennas. This requires a co-design of the entire system. Therefore, we begun by studying the characteristics of the channel propagation channel at 60GHz according to the IEEE 802.15.3c and IEEE 802.11.ad models. This PHD thesis proposes a new transceiver architecture based on multi-band impulse mode, with On Off Keying modulation schema and non coherent receiver. This architecture is dedicated to nomadic systems offering high data and reconfigurable rates, low complexity, low power consumption for short communications. Analysis and performances for the proposed architecture are presented. More than 2 Gbps at 2 m are obtained. The imperfections of some critical blocks and their impact on the transmitted pulses were analysed and thus the performance of the system has been established. The potentiality of microstrip band pass filter bank presenting a constant relative bandwidth and reasonable insertion losses is presented in this study. The study of pulse generation solutions, switchers, amplification stages and antennas are detailed and discussed in the last two chaptersconstant relative bandwidth and reasonable insertion losses is presented in this study.The study of pulse generation solutions, switchers, amplification stages and antennas are detailed and discussed in the last two chapters.PARIS-EST-Université (770839901) / SudocSudocFranceF
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