Impedance Compressing Matching Network Based on Two-Port Network Analysis for Wireless Power Transfer System

This article proposes a new design method of impedance matching networks for wireless power transfer (WPT) systems. In WPT systems, the input impedance of resonator varies over a wide range rather than having a fixed value due to coupling variation. In conventional systems, tunable matching networks have been commonly used to match the variable impedance to a fixed impedance. Three-port impedance compression networks have also been proposed to eliminate the mechanical tuning processes. In this article, a two-port impedance compressing matching network (ICMN) is proposed that addresses the load variations without the need for any mechanical tuning. In impedance matching, a two-port network can have a low design degree-of-freedom for load variation. In order to overcome this limitation, this article analyzes the general model of a two-port network and proposes a systematic design procedure. The effectiveness of the proposed method is verified with a design example that constructs an ICMN ¹ .