Two-Stage Optimization of DC Equivalent Series Resistances in Compact PCB-Based Resonant Couplers for Capacitive Power Transfer

A highly integrated printed circuit board (PCB)-based resonator coupler has been recently proposed for high-frequency, high-efficiency capacitive power transfer (CPT) systems. However, the design parameters of these compact PCB-based couplers have yet to be fully optimized. This paper presents a two-stage optimization strategy aimed at minimizing the DC equivalent series resistances (ESRs) of the coupler, thereby further improving CPT efficiency. Experimental results demonstrate that the optimized couplers achieve DC ESR reductions of 27.3% and 67.9% for the inner and outer coils, respectively, compared to conventional designs.