A Dual-Band Compact Integrated Rectenna for Implantable Medical Devices

This work describes a dual band compact fully integrated rectenna circuit for implantable medical devices. The implantable rectenna circuit consists of tunnel diode 10×10µm2 QW-ASPAT (Quantum Well Asymmetric Spacer Tunnel Layer diode) was used as the rectifier due to its temperature insensitivity and non-linearity compared with conventional SBD diodes. A miniaturized dual band implantable folded dipole antenna with multiple L-shaped conducting sections for operation in the WMTS band is 1.5GHz and ISM band of 5.8GHz. High dielectric constant material Gallium Arsenide (εr=12.94) and folded geometry helps to design compact antennas with a small footprint of 2.84mm3 (4.5×1×0.63) mm3. Four-layer human tissue model was used, where the antenna was implanted in the skin model at depth of 2mm. The 10-dB impedance bandwidths of the proposed compact antenna at 1.5GHz and 5.8GHz are 227MHz (1.4-1.63GHz) with S11 is -22.6dB and 540MHz (5.47-6.02GHz) with S11 is -23.1dB, whereas gains are -36.9dBi, and -24.3dBi, respectively. The output DC voltage and power of the rectenna using two stage rectifiers are twice that produced by the single stage at input RF power of 10dBm

Large-Scale Sequentially-Fed Array Antenna Radiating Flat-Top Beam for Microwave Power Transmission to Drones

Power beaming is one of the core technologies for microwave power transmission (MPT) systems. Effective plane-to-plane power beaming requires not only high point-to-point efficiency but also appropriately-shaped beam to extract the best performance of receivers (rectennas). Flat-top beam plays an important role in plane-to-plane power beaming for drones where the output dc power from rectennas should be maximized to drive motors. It is challenging to develop a large-scale flat-top-beam array with appropriate distribution circuits. Sequential array is also required to suppress axial ratio on the receiving plane. In this paper, we proposed a simplified but effective way to create a large-scale sequential array for flat-top beam at C-band. The series feed and block-oriented sequential array were adopted to keep the circuit design and fabrication simple while obtaining a sufficient point-to-point efficiency and good axial ratio on the receiving plane. A 196-element phased array with microstrip antennas was developed by subdividing the whole array into four 49-element blocks for simplicity of the circuit design and implementation of block-oriented sequential array. The efficiency between the transmitting ports and the receiving ports was 50.6 % in simulations and 32.0 % in measurements. In the measured flat-top beam, the transmitted power was uniformly concentrated within the receiving plane and the axial ratio of the beam was successfully suppressed to less than 3 dB on most of the receiving area. A flight test of a microwave-powered drone was conducted where a micro-drone successfully flew for seven minutes only with wireless power

A Dual-Band Compact Integrated Rectenna for Implantable Medical Devices

This work describes a dual band compact fully integrated rectenna circuit for implantable medical devices (IMDs). The implantable rectenna circuit consists of tunnel diode 10×10μm2 QW-ASPAT (Quantum Well Asymmetric Spacer Tunnel Layer diode) was used as the RF-DC rectifier due to its temperature insensitivity and nonlinearity compared with conventional SBD diode. SILVACO atlas software is used to design and simulate 100μm2 QW InGaAs ASPAT diode. A miniaturized dual band implantable folded dipole antenna with multiple L-shaped conducting sections is designed using CST microwave suits for operation in the WMTS band is 1.5GHz and ISM band of 5.8GHz. High dielectric constant material Gallium Arsenide (εr=12.94) and folded geometry helps to design compact antennas with a small footprint of 2.84mm3 (1×4.5×0.63) mm3. Four-layer human tissue model was used, where the antenna was implanted in the skin model at depth of 2mm. The 10-dB impedance bandwidth of the proposed compact antenna at 1.5GHz and 5.8GHz are 227MHz (1.4-1.63GHz) with S11 is -22.6dB and 540MHz (5.47-6.02GHz) with S11 is -23.1dB, whereas gains are -36.9dBi, and -24.3dBi, respectively. The output DC voltage and power of the rectenna using two stage voltage doubler rectifier (VDR) are twice that produced by the single stage at input RF power of 10dBm

Next-generation IoT: harnessing AI for enhanced localization and energy harvesting in backscatter communications

Ongoing backscatter communications and localisation research have been able to obtain incredibly accurate results in controlled environments. The main issue with these systems is faced in complex RF environments. This paper investigates concurrent localization and ambient radio frequency (RF) energy harvesting using backscatter communication systems for Internet of Things networks. Dynamic real-world environments introduce complexity from multipath reflection and shadowing, as well as interference from movements. A machine learning framework leveraging K-Nearest Neighbors and Random Forest classifiers creates robustness against such variability. Historically, received signal measurements construct a location fingerprint database resilient to perturbations. The Random Forest model demonstrates precise localization across customized benches with programmable shuffling of chairs outfitted with RF identification tags. Average precision accuracy exceeds 99% despite deliberate placement modifications, inducing signal fluctuations emulating mobility and clutter. Significantly, directional antennas can harvest over −3 dBm, while even omnidirectional antennas provide −10 dBm—both suitable for perpetually replenishing low-energy electronics. Consequently, the intelligent backscatter platform localizes unmodified objects to customizable precision while promoting self-sustainability

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

Towards Battery-Free Internet of Things (IoT) Sensors: Far-Field Wireless Power Transfer and Harmonic Backscattering

RÉSUMÉ Notre vie tend à être plus agréable, plus facile et plus efficace grâce à l'évolution rapide de la technologie de l'Internet des objets (IoT). La clef de voute de cette technologie repose essentiellement sur la quantité de capteurs IoT interconnectés, que l’on est en mesure de déployer dans notre environnement. Malheureusement, l’électronique conventionnelle fonctionnant sur piles ou relié au réseau électrique ne peut pas constituer une solution durable en raison des aspects de coût, de faisabilité et d'impact environnemental. Pendant ce temps, le changement climatique dû à la consommation excessive de combustibles fossiles continue de s'aggraver. Il devient donc urgent de trouver une solution pour l’alimentation électrique des capteurs IoT géographiquement répartis à grande échelle, afin de simultanément soutenir la mise en oeuvre de nombreux capteurs IoT tout en limitant leur poids environnemental. L'énergie radiofréquence (RF) ambiante, qui sert de support à l'information sans fil, est non seulement capitale pour notre société, mais aussi omniprésente dans les zones urbaines et suburbaines. Elle permet de réaliser des communications et des détections sans fil. Cependant, l'énergie RF ambiante est majoritairement « gaspillée » car seule une toute petite partie de la puissance transmise est effectivement reçu ou « consommée » par le destinataire. C'est pourquoi le recyclage de l'énergie RF ambiante est une solution prometteuse pour alimenter les capteurs IoT. Pour certains capteurs IoT consommant une puissance plus élevée, l’apport d'énergie sans fil pourra similairement se faire par des centrales électriques spécialisées, suivant le même schéma d’alimentation sans fil. Pour utiliser et récupérer cette énergie RF, cette thèse présente deux techniques principales : la récupération/réception de puissance sans fil en champ lointain (wireless power transfer: WPT) et la rétrodiffusion d'harmoniques. Le chapitre 2 aborde les différents mécanismes de conversion de fréquence entre le WPT en champ lointain et la rétrodiffusion d'harmoniques. La récupération de WPT en champ lointain consiste à convertir l'énergie RF en puissance continue. En revanche, la rétrodiffusion d'harmoniques a pour but de convertir l'énergie RF dans une autre fréquence, dans la plupart des cas, la composante harmonique de rang 2. A titre d'étape préliminaire de recherche et d'étude de faisabilité, une cartographie de la densité de l'énergie RF ambiante dans les zones centrales de l'île de Montréal est résumée au chapitre 3. Contrairement aux mesures traditionnelles précédentes effectuées à des endroits fixes, cette mesure dynamique a été réalisée le long des rues, des routes, des avenues et des autoroutes pour couvrir une large zone.----------ABSTRACT Our life is becoming more convenient, efficient, and intelligent with the aid of fast-evolving Internet of Things (IoT) technology. One essential foundation of IoT technology is the development of numerous interrelated IoT sensors that are distributed extensively in our environment. However, conventional batteries/cords-based powering solutions are certainly not an acceptable long-term solution, considering the incurred cost, feasibility, most of all, environmental impact. Meanwhile, climate change due to excessive consumption of fossil fuels is worsening day by day. Therefore, a transformative powering solution for such large-scale and geographically scattered IoT sensors is of extreme importance in support of such extensive IoT sensors implementation while simultaneously mitigating its environmental burden. Serving as a critical information carrier, ambient radiofrequency (RF) energy is pervasive in urban and suburban areas to realize wireless communication and sensing. However, part of ambient RF energy is dissipated due to path loss if not fully consumed by end-users. Hence, recycling the wasted ambient RF energy to power IoT sensors is a promising solution. The concept of harnessing wireless energy for powering IoT sensors requiring a higher power supply is also feasible through the dedicated wireless power delivery from specialized power stations, which can be an effective supplement. To realize the RF power scavenging, this thesis research introduces two mainstream techniques: far-field wireless power transfer (WPT) and harmonic backscattering. Chapter 2 discusses the different frequency conversion mechanisms applied for far-field or ambient WPT harvesting and harmonic backscattering. Far-field WPT harvesting converts RF energy into dc power (zeroth harmonic). In contrast, harmonic backscattering upconverts RF energy into its harmonics, in most cases, the second harmonic component. As a preliminary research step and a feasibility study, a survey of ambient RF energy density in the core areas on Montreal Island is summarized in Chapter 3. Different from the previously published traditional measurements at fixed locations, this dynamic measurement is carried out along streets, roads, avenues, and highways to cover a large area. Also, a stationary measurement in Downtown Montreal is to reveal whether human activities are able to bring visible change to ambient RF energy levels. This work demonstrates how much ambient RF energy is available in free space and acts as a significant reference for researchers and engineers designing ambient RF energy harvesting circuits/systems for practical applications

Recent Wireless Power Transfer Technologies

The Wireless Power Transfer concept is continuously and rapidly evolving and new challenges arise every day. As a result of these rapid changes, the need for up-to-date texts that address this growing field from an interdisciplinary perspective persists. This book, organized into ten chapters, presents interesting novel solutions in the exploitation of the near- and far-field techniques of wireless power transfer that will be used in the near future, as well as a bird's eye view of some aspects related to an emerging technological area that will change our lives and will change the paradigm of how we use electrical equipment. The book covers the theory and also the practical aspects of technology implementation in a way that is suitable for undergraduate and graduate-level students, as well as researchers and professional engineers