W-Band Substrate Integrated Waveguide Radar Sensor based on Multi-Port Technology

Abstract-A 94 GHz collision avoidance radar sensor based on multi-port technology is proposed. This sensor makes use of substrate integrated waveguide (SIW) multi-port circuit fabricated on alumina substrate. The use of integrated waveguide allows for a full integration of the radar sensor frontends. A specific base-band circuit generates in-phase and inquadrature signals used to obtain the relative speed of target (including the moving direction) and the distance by elementary signal processing. Simulation and measurement results validate the operating principle of the proposed sensor and also indicate excellent results for relative velocity measurement together with good accuracy of distance measurement

Embedded vector measurement of RF/microwave circuits in LTCC technology

As the number of wireless systems and standards continues to increase, RF hardware re-use is becoming more and more important to reduce cost and size and eliminate unnecessary component redundancy. One way of maximizing RF hardware re-use is to deploy reconfigurable circuits. This is turn relies on embedded vector measurement to ensure the reconfigurable hardware operates as required. Conventional vector measurement techniques require costly and bulky Vector network analyzers or slightly more compact six-port junctions. Both options require the use directional couplers to sample forward and backward traveling waves, which increases their size and limits their suitability for embedding in reconfigurable RF hardware. Non-directional four-port interferometersoffer an alternative solution for embedded vector measurement that is characterized by a very small size, very low coupling, and ease of integration. In the present work, a new 3D 4-port non-directional reflectometer for measuring complex reflection coefficients is proposed. The proposed reflectometer features two optimized non-directional sniffers positioned below a transmission line with buried lines to carry the sniffed signals to power detectors in LTCC technology. Vertical transitions from the buried lines to surface are designed and optimized. 3D electromagnetic field simulations are used to optimize the proposed design in order to obtain the S-parameter of the structure. Two LT5582 power detector circuits with 57 dB dynamic range are used to detect the coupled power. A prototype of the proposed reflectometer is fabricated in LTCC (Ferro L8) in LACIME laboratory and used to measure 45 different complex loads. The obtained results show excellent agreement with VNA measurements showing errors below 0.3 dB for amplitude and below 3° for phase

Simultaneous Wireless Power Transmission and Data Communication

RÉSUMÉ : Le développement rapide des systèmes électroniques sans fil de faible consommation de puissance a conduit à d'innombrables activités de recherche dans le cadre de la faisabilité d'une alimentation à distance ou sans fil de ces systèmes. Par conséquent, la transmission d'énergie sans fil (WPT), qui est développé comme une technique prometteuse pour alimenter les appareils électroniques à longue distance et permettre la conception et le développement de systèmes auto-alimentés, est devenue un centre d'intérêt depuis de nombreuses années. Les antennes de redressement connues sous le nom de rectennas, sont les éléments les plus importants de transmission à longue portée d'énergie sans fil. L'efficacité de rectennas dépend essentiellement de leurs antennes et les circuits redresseurs associés. Par conséquent, pour concevoir une antenne redresseuse à haut rendement qui garantit la qualité d'un système WPT, plus d'attention devrait être concentré sur l’étude, l'analyse et le développement des antennes à gain élevé et redresseurs à haute efficacité de conversion RF-DC. Dans la littérature, différentes configurations de circuit antenne redresseuse, opérant principalement à basse fréquence tels que 2,45 GHz et 5,8 GHz, ont été largement étudiés. Cependant, il existe quelques études rapportées à la fréquence à ondes millimétriques, bien que les avantages de plus petite taille et l'efficacité du système global plus élevée pour la transmission à longue distance peuvent être obtenus à la fréquence à ondes millimétriques. D'autre part, les circuits rectennas peuvent tout simplement récupérer l'énergie, mais ils ne peuvent pas décoder le signal transmis à des fins de communication. Cependant, la transmission de données est une condition essentielle dans les systèmes de communication sans fil. Par conséquent, si la capacité de détection et de traitement du signal peut être ajoutée à une architecture de rectenna, alors, un récepteur de communication sans fil transmettant simultanément de l'énergie et de données peut être réalisé. La réalisation d'un tel système peut être considérée comme une approche prometteuse pour la prochaine génération de systèmes de communication auto-alimentés. Cette thèse de doctorat vise à examiner et à démontrer un système de transmission d'énergie sans fil et également un récepteur avec la capacité de récupérer l’énergie et de données de communication simultanément fonctionnant aux fréquences à ondes millimétriques. Pour atteindre ces objectifs, différentes structures de circuit redresseurs sont étudiés, conçus et mesurés expérimentalement.----------ABSTRACT The rapid development of low power wireless electronic systems has led to countless research activities in connection with the feasibility of a remote or wireless powering of those systems. Therefore, wireless power transmission (WPT) has become a focal point of interest since many years, which is being developed as a promising technique, for powering electronic devices over distance and for enabling the design and development of self-powered systems. The rectifying antennas known as rectennas are the most important elements in long-range wireless power transmission. The efficiency of rectennas mainly depends on their antennas and the related rectifier circuits. Therefore, to design a high-efficiency rectenna that guarantees the quality of a WPT system, more focus should be concentrated on the investigation, analysis and development of high-gain antennas and performance-driven rectifiers with reference to high RF-to-DC conversion efficiency. In the literature, different configurations of rectenna circuit, mainly operating at low frequency such as 2.45 GHz and 5.8 GHz, have been widely investigated. However, there are just a few reported studies at millimeter-wave frequency although the advantages of more compact size and higher overall system efficiency for long distance transmission can be obtained at millimeter-wave frequency. On the other hand, rectenna circuits can just scavenge energy and they cannot decode the transmitted signal for communication purpose. However, 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 receiver with simultaneous wireless power transmission and data communication can be realized. The realization of such a system can be considered as a promising approach for the next generation of self-powered communication systems. This PhD dissertation aims to investigate and demonstrate a system of wireless power transmission and also a receiver with the capability of simultaneous wireless energy harvesting and data communication operating at up-microwave and millimeter-wave frequency