Shady Keyrouz

A novel application for frequency selective surfaces (FSSs) is presented. The novel FSS design can harvest power from arbitrarily polarised incident waves. The design does not involve a matching network, which results in a simple, polarisation‐independent power harvester. An accurate analytical procedure, to calculate the impedance of the commercially available Schottky rectifiers, is presented. The results are validated by full‐wave simulations and by measurements. A simple equivalent circuit model to predict the transmission and reflection characteristics of the gridded‐square‐loop FSS is employed. The design method is validated for different polarisations and for different incident angles. The addition of lumped elements ( R , L , C ) in the metallic conductive grid of the FSS is investigated. The waveguide simulator method and full‐wave simulations are employed to validate the derived analytical equations. A 3 × 3 and a 5 × 5 RF harvesting FSS have been designed, simulated, fabricated and validated. A radio frequency (RF) to DC conversion efficiency of 25% for the 3 × 3 RF harvester and 15.9% for the 5 × 5 RF harvester is measured at an RF input power level of −6 dBm.

This paper presents the design, simulation, fabrication and measurements of a 50 ohm rectenna system. The paper investigates each part (in terms of input impedance) of the rectenna system starting from the antenna, followed by the matching network, to the rectifier. The system consists of an antenna, which captures the transmitted RF signal, connected to a rectifier which converts the AC captured signal into a DC power signal. For maximum power transfer, a matching network is designed between the rectifier and the antenna. At an input power level of −10 dBm, the system is able to achieve an RF/DC power conversion efficiency of 49.7%.