40.68 MHz Digital On-Off Delay-Compensated Active Rectifier for WPT of Biomedical Applications

Abstract

A digitally controlled on-off delay-compensated 40.68 MHz full-wave active rectifier is proposed for wireless power transfer (WPT) of biomedical applications. It consists of two NMOS active diodes and a cross-coupled PMOS transistor-pair. High efficiency is achieved by digital techniques that eliminate turn-on delay, reverse current and multiple pulsing. The proposed design and one state-of-the-art design are implemented with 0.13 μm CMOS process for comparison. The measured maximum voltage conversion ratio (VCR) is 0.97, and the measured maximum power conversion efficiency (PCE) is 93.2% for a 500 Ω load resistance.