Mode-Switching based On-Off Keying modulation to achieve impedance matching in Wireless battery Charging System

Achieving high efficiency in the constant-voltage (CV) mode of battery charging algorithms like constant-current/constant-voltage (CC/CV) requires impedance matching over a wide load range. Conventional wireless battery charging systems have incorporated converters on the output side or utilized complex topologies with extra components to achieve impedance matching. In this study, we propose a method to achieve impedance matching by employing a load variation technique that limits the transmitted power through the duty cycle and mode conversion of a dual-side Bridge (DSB). The DSB utilizes a mode-switching based on –off modulation technique and features an output-side full-wave rectifier configured with switches. The effectiveness of the proposed method was verified using a 320 W prototype.