Enhanced radio frequency rectifier with a power splitting/combining topology for wireless energy transfer and harvesting

Abstract

Power splitting of the input radio frequency (RF) signal is used to improve the efficient power range of a RF rectifier. Direct current (dc) power at the output of every rectifying branch is then combined over a resistive load and thus resulting in a single dc output. The enhancement in efficient power range, over which the power conversion efficiency (PCE) remains ≥ 50%, is determined to be 2.8 dB. The article starts by a theoretical analysis that addresses the negative effects of the diode's breakdown voltage, formulates an equation that predicts the maximum output dc voltage at saturation, and introduces a method that can improve the PCE of a typical shunt-type diode rectifier at low power levels. As a result, a rectifying system is designed and tested as a proof of concept. The proposed circuit, with the enhanced power range, is designed to operate within the power span from −10 dBm up until 10 dBm. Such system is suitable for operation in RF wireless energy transfer and energy harvesting applications. © The Institution of Engineering and Technology 2019