Impedance Transformers

Non

Development of equal and unequal filtered power splitter using substrate integrated waveguide

The objective of this thesis is to investigate and provide better solution to producing filtered power splitter with compact size and with use of no resistors for its isolation. The background investigation and utilisation of the established theories build up the design equations that are adapted to power dividers. These dividers contain filtering characteristics and are employed in microstrip and substrate integrated waveguide technology. The work involves the design of a filtered power splitter with bandpass characteristics. It uses the conventional filter design synthesis to develop the design parameters that establish the coupling between the common resonator of the power splitter and the next resonator towards the output ports. An equal and an unequal division using a 5-pole, 9-square resonators is used verify this concept; this is also implemented in microstrip using Square open loop resonators (SOLR) and in SIW. Furthermore, a 3-pole 5-square resonators is also implemented in SIW; all of these operating at 2 GHz. For the equal split, the 5th order microstrip gives a bandwidth, minimum insertion loss, maximum return loss and isolation of 120MHz, 3.12dB, 15dB and 12.6dB respectively and the 3rd order SIW gives a bandwidth, minimum insertion loss, maximum return and isolation of 99Mhz, 3.57dB, 17.1dB and 6.79dB respectively; whilst the 5th order SIW gives a bandwidth, minimum insertion loss, maximum return and isolation of 140Mhz, 3.87dB, 18.3dB and 14.79dB respectively. However, it is recommended that this work can be extended to more than two output ports, to improve isolation, increase the Q factor and match the output ports

Simultaneous Data Communication and Power Transfer Technique with Multiport Interferometric Receiver

RÉSUMÉ Le problème de la communication est généralement présenté comme un problème de trans-mission d’un message généré d’un point a un autre. Certains systèmes de communication modernes sou˙rent de contraintes énergétiques sévères. Avec le développement rapide des systèmes électroniques sans fil de faible puissance, d’innombrables activités de recherche ont été menées en vue d’explorer la faisabilité d’une alimentation à distance ou sans fil de ces systèmes. Par conséquent, la transmission d’énergie sans fil (WPT) est en cours de développe-ment en tant que technique prometteuse pour alimenter des appareils électroniques à distance et pour prolonger la durée de vie des réseaux sans fil à contrainte d’énergie. Parmi les éner-gies renouvelables récoltées dans l’environnement, les signaux RF rayonnés par les émetteurs peuvent être une ressource viable pour le transfert d’énergie sans fil, tandis que les signaux RF ont été largement utilisés comme véhicule pour la transmission d’informations sans fil (WIT). Par conséquent, le transfert simultané d’informations et la plateforme de transfert de puissance sans fil (SWIPT) deviennent bénéfiques, car il réalise les deux utilisations utiles des signaux RF en même temps et il o˙re ainsi potentiellement une grande commodité aux utilisateurs mobiles. L’antenne redresseuse, qui combine des fonctionnalités du redresseur et de l’antenne, est un élément clé pour la transmission et la récolte d’énergie sans fil. L’eÿcacité de conversion du circuit de redressement détermine les performances globales de l’antenne redresseuse. Par conséquent, pour concevoir une antenne redresseuse à haute eÿcacité qui peut garantir la qualité d’un système WPT, il convient de se concentrer davantage sur l’investigation, l’analyse et le développement de redresseurs axés sur les performances en référence à une eÿcacité de conversion radio fréquence à courant continu. D’un autre côté, les circuits redresseurs peuvent simplement récupérer l’énergie et ils ne peuvent pas décoder le signal transmis pour fins de communication. Cependant, la transmission de données est une exigence essentielle des systèmes de communication sans fil. Par conséquent, si la capacité de détection et de traitement du signal peut être ajoutée à une architecture antenne redresseuse, un récepteur avec transmission de puissance sans fil et communication de données simultanées peut être réalisé. Ce mémoire vise à étudier et à démontrer un récepteur de multifonction et de multiport qui a la capacité de collecter simultanément l’énergie sans fil et les données de communication fonctionnant à la fréquence des microondes.----------ABSTRACT The problem of communication is usually cast as one of transmitting a message generated at one point to another point. Some modern communication systems are known to suffer from severe energy constraints and power consumptions. With the rapid development of low power wireless electronic systems, countless research activities have been carried out to explore the feasibility of a remote or wireless powering of those systems. Therefore, wireless power transmission (WPT) is being developed as a promising technique, for powering electronic devices over distance and for prolonging the lifetime of energy constrained wireless networks. Among the renewable energy harvested from the environment, the RF signals radiated by transmitters can be a viable resource for wireless power transfer, while RF signals have been widely used as a vehicle for wireless information transmission (WIT). Therefore, simultaneous wireless information and power transfer (SWIPT) platform becomes appealing since it realizes both useful utilizations of RF signals at the same time, and thus potentially offers great convenience to mobile users. The rectenna, combining the functionalities of rectifier and antenna, is a key element for wireless power transmission and harvesting. The conversion efficiency of the rectifying circuit determines the overall performance of the rectenna. Therefore, to design a high-efficiency rectenna that can guarantee the quality of a WPT system, more focus should be concentrated on the investigation, analysis and development performance-driven rectifiers with reference to high RF-to-DC conversion efficiency. On the other hand, rectenna circuits can just scavenge energy and they cannot decode the transmitted signal for communication purpose. How-ever, the data transmission is an essential requirement of wireless communication systems. Therefore, if the ability of signal detection and processing can be added to a rectenna architecture then a multi-function receiver with simultaneous wireless power transmission and data communication can be realized.This dissertation aims to investigate and demonstrate a multi-function and multi-port receiver with the capability of simultaneous wireless energy harvesting and data communication operating at microwave frequency. To achieve these goals, it becomes interesting when a single receiver chain is able to convert the RF power to DC power, while at the same time converting the RF modulated signal to BaseBand (BB) signal. Therefore, the fundamental methodology to receive and convert the RF signal to BB while simultaneously harvesting power is derived and analyzed in this work

Antenna Designs for 5G/IoT and Space Applications

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