Efficient quad-band RF energy harvesting rectifier for wireless power communications

Abstract

This work presents a compact quad-band rectifier implemented using a multi-stub impedance matching network (IMN). The IMN comprises three blocks of multiple stub tuning connected via a meandered line (MDL) to achieve multiple frequency susceptance blocks. The proposed rectifier is designed to operate at (1.82 GHz, 2.1 GHz, 2.4 GHz, and 2.67 GHz) for GSM/1800, UMTS/2100, Wi-Fi, and LTE/2600 frequency bands. The rectifier occupies a total area of 0.45λg×0.25λg on the RT/Duroid 5880 PCB board using full ground architecture. The fabricated rectifier achieved RF-to-dc (radio frequency direct current) power conversion efficiency (PCE) of (31.7%, 23.5%, 25.4%, 15.5%) across the four operating frequencies for an input power of −20 dBm, respectively. The proposed quad-band rectifier realized a peak RF-to-dc PCE of 86.8% from the four-tones RF input power at 3 dBm. The rectifier can also attain over 55% RF-to-dc PCE along 1.7 GHz to 2.4 GHz frequency range, and at 2.67 GHz for 0 dBm input power levels. An ambient output dc voltage of 0.433 V for multi-tone input signals is realised by the proposed rectifier. The rectifier operates a bq25504-674 power management module (PMM). An output dc voltage of 1.271 V is achieved through the PMM connection. Hence, with proper management of the proposed rectifier, the harvested ambient RF signals can activate a number of low-powered devices.