Design of a wideband RF rectifier for enhanced wireless power transfer in biomedical implants supporting white space WiFi and LTE bands

This paper introduces a novel design methodology for a high efficiency, wideband RF-rectifier. The proposed structure employs a two branch cell configuration integrated with an L-shunt matching network (MN), a radial stub, and a series inductor to enhance performance. Optimization of the rectifier has resulted in peak power transfer efficiency (PTE) across the 2.37-2.70 GHz frequency range, thereby making it ideal for use in white space Wi-Fi and LTE systems. Both simulation and measured results reveal favorable performance, with the power conversion efficiency (PCE) reaching a peak value of 66.25% at an input power level of 5 dBm. At an input power of - 20 dBm, the rectifier achieves RF-to-DC conversion efficiencies between 11.50 and 13.5%, indicating reliable and effective operation over a spectrum of input power levels. The rectifier, fabricated on an RT/Duroid substrate, features a compact footprint measuring 19.75 mm × 15.20 mm and employs a single series diode (SSrd) configuration. A sequential matching technique is implemented in the design to obtain wide impedance bandwidth, which enables effective utilization of the desired frequency range. The proposed rectifier exhibits significant potential for use in wireless power transfer systems (WPTs) targeting biomedical implants, particularly in situations that demand stringent control of ambient power resources.