Hybrid Class-E low dv/dt rectifier for high frequency inductive power transfer

This paper presents the design and implementation of a voltage driven hybrid Class-E low dv/dt half wave rectifier with focus on high frequency (HF), 3 - 30 MHz, inductive power transfer (IPT). The hybrid rectifier is capable of absorbing the parasitic capacitance of the utlised diode while maintaining the properties of the conventional Class-E rectifier with a series capacitor. The hybrid rectifier introduces two degrees of design freedom which enable circuit optimisation over a wide range of IPT requirements. A case study investigated the performance of three different hybrid rectifier designs of the same input (AC) and output (DC) resistance. All designs proved to be tolerant to diode parasitics as they maintained nearly constant efficiency and input resistance profiles over the entire tested output power range (50 W to 200 W). The worst case deviations in efficiency and input resistance profiles were 4 % and 7 % respectively. The lowest recorded receiving end efficiency was 91 % and the highest was greater than 95 %, when a 14.5 A current capability SiC Schottky diode was deployed.