Enhancement Method of Efficiency and Working Range in Bio-Implant Wireless Power Transfer

An effective control method with improved energy efficiency and extended working range based on $1X/2X$ reconfigurable rectifier is presented for wireless power transfer in implantable medical devices (IMDs). Compared to the conventional method that fixes the duty cycle of the reconfigurable rectifier to be around 50%, the proposed method optimizes the duty cycle for different coupling and loading conditions, so the system efficiency is significantly improved and the workable coupling and loading range is greatly extended. Simulation results in a commercial 0.18 $\mu m$ CMOS technology validate the proposed method.