Ambient Electromagnetic wireless energy harvesting using multiband planar antenna

Abstract

Ambient Electromagnetic (EM) energy harvester using multiband planar antenna and broadband radio frequency (RF) to direct current (DC) circuit is presented. The wireless EM harvester consists of a Printed Circuit Board (PCB) planar antenna and RF to DC circuit using schottky diodes and passive components for impedance matching. Measured and simulated S11 and gain for various resonant frequencies of the multiband antenna are presented. Average open circuit voltage and efficiency of the broadband RF to DC circuit from 800 MHz to 2 GHz is 0.45 V and 8% respectively at -0 dBm input power. It is shown in this work that using a single multiband antenna and broadband RF to DC circuit, the performance of an EM wireless harvester can be enhanced by harvesting energy from different ambient EM frequencies in its operating band at the same time.