ISBN 978-3-8439-3905-8

978-3-8439-3905-8, Reihe Elektrotechnik

Defu Wang
Highly Efficient Microwave Rectifiers for RF Energy Recycling Technique

148 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2018), Hardcover, A5

Zusammenfassung / Abstract

Microwave rectifiers have recently attracted more particular focus on the interaction between human utilisation of consumer products, wireless charging and battery life extension of electronic devices. By incorporating a microwave rectifier as part of a receiver or transmitter, the overall DC power consumption can be reduced. As part of a receiver, a microwave rectifier typically manifests itself as a rectenna which replaces a simple antenna of a Receiver. The rectenna recycles the received RF energy and converts it to a DC power, which is conventionally referred to as Wireless Energy Recycling (WER). Due to the existence of various wireless power transmitted RF signals that operate at different frequency bands, it would be prudent to design a highly efficient rectifier for an WER System that can operate over a multiple frequency bands. This in turn would allow the rectenna to convert varies sources of RF energy and therefore expand its suitability for a wide selection of products.

As part of a transmitter, a combining resistor can be substituted by a microwave rectifier so that any RF power lost within the combination can be recycled and recovered back to the DC power supply of the transmitter. This type of rectification is typically referred to as Circuitry Energy Recycling (CER). For successful implementation of CER, the microwave rectifier has to present a constant resistance so that it can accurately replace the isolating resistor. However, the Input impedance of a microwave rectifier varies as a function of input power. In order to design a microwave rectifier suitable for WER Systems, where wide bandwidth characteristics are prudent to be desired, this theis will investigate the design and realisation of highly efficient microwave rectifiers with bandwidth-extension techinques. Moreover, the impedance compression technique has been presented for microwave rectifiers in CER System.

The works presented in this thesis highlight the feasibility of realising high Performance microwave rectifiers that can be implemented into a suitable receiver or transmitter to ensure effective RF energy recycling.