An Efficiency-Enhanced Active Rectifier with Offset-Controlled Comparators for WPT Systems

This paper presents an efficiency-enhanced active rectifier tailored for on-chip wireless power transfer (WPT) systems. Two proposed offset controllers are implemented in the comparator of the rectifier. These controllers are instrumental in minimizing the switch-on and switch-off delays of power transistors within the rectifier. Consequently, the active rectifier achieved a power conversion efficiency (PCE) of 93.3% under conditions with a 2.45V peak 13.56MHz RF input signal, a 0.6kΩ output load resistance, and an output DC voltage of 2.3V. Additionally, the overall efficiency of the designed WPT system reached 72.5%.