Simple design approach for asymmetric resonant inductive coupled WPT systems using J-inverters

This paper presents a simple and precise design method for asymmetric resonant inductive coupled wireless power transfer (WPT) systems without the involvement of circuit or electromagnetic (EM) simulators. The design method is based on the generalized second-order band-pass filter (BPF). First, the values of the BPF's J-inverters are computed based on the mutual coupling between the transmitter (TX) and the receiver (RX). Then, the required components are extracted from the J-inverters values. We achieved good agreements between the analytical design procedure, the circuit and the EM simulations, and the measurements. The measured efficiency is 75% at a transmission distance of 38 mm, and the sizes of the TX and RX are 50×50 mm2 and 30×30 mm2, respectively.