Wireless power transfer system with load-independent inverse class-E oscillator

This paper proposes a wireless power transfer (WPT) system using the load-independent inverse class-E oscillator. The proposed system realizes autonomous operation without using external driving circuits. Therefore, it is easier to design the power-transmission inverter at high frequencies, in particular. Moreover, the proposed WPT system has load-independent characteristics. It maintains constant output voltage and zero current switching (ZCS) of the MOSFET without applying any controls for load variations. We conducted the circuit analysis and the experimental verifications for the proposed system. In the experiment, the proposed system achieved 76.5 % power-delivery efficiency with 20 W output power and 1 MHz operating frequency at the rated state.