Dual-Band Rectifier Using Coupled Inductor for Wireless Power Transfer Receivers

This article proposes a dual-band wireless power receiver capable of both kHz-band and MHz-band wireless charging. The proposed rectifier automatically switches between two charging modes depending on the frequency band of the input signal. It operates as a class D rectifier at low-frequency band input and a class E rectifier at high-frequency band input. This mode change requires no active elements, additional sensing circuits, or external control signals. Therefore, the proposed circuit can be utilized as a low-cost, high-power-density dual-band wireless power receiver. The proposed circuit is verified through a prototype supporting 45 W low-frequency charging and 20 W high-frequency charging.