Integrated Hybrid Inductive and Capacitive Power Transfer System with Asymmetrical PCB Self-Resonator

This paper presents the design of a hybrid wireless power transfer (WPT) system with asymmetrical printed-circuit-board (PCB) based self-resonators, integrating both inductive and capacitive power transfer (IPT and CPT) channels. The PCB-based self-resonant coupler consists of four PCB-coil plates with two different sizes, which work as the coupled inductance for IPT as well as the capacitive plates for CPT. With a typical stacked four-plate configuration, both inductive and capacitive mutual couplings are achieved between transmitter and receiver, contributing to a self-resonant hybrid WPT with an integrated coupler and no external compensation components. Detailed theoretical analysis and system modeling are provided and a 250W hybrid WPT system is implemented with an asymmetrical coupler consisting of 210-mm and 140-mm PCB-coil plates. With transfer distances of 12mm and 37mm, the implemented hybrid WPT system works at the self-resonant frequencies of 3.19MHz and 3.57MHz, which respectively demonstrate a peak DC-DC efficiency of 87.3% with 155.7W at 12mm and 86.7% with 237.5W at 37mm, validating the effectiveness of the designed hybrid WPT system.