LCC Matching Network Design for a MHz Class D GaN PA Considering Parameter Uncertainties

The LCC matching network plays an important part in Megahertz Wireless Power Transfer (MHz WPT) systems. The soft switching technique is another topic that needs to be focused on when designing MHz WPT systems. In this paper, the impedance converting characteristics of the LCC matching network is applied to realize the soft switching of Megahertz Class D GaN power amplifiers (MHz Class D GaN PA). The criterion for the soft switching of MHz Class D GaN PA is expressed in the form of a simple equation. Parameter uncertainties in real MHz WPT systems are unavoidable and corresponding analysis is also conducted. A 6.78 MHz WPT system with Class D PA is built to realize robust soft switching and to measure the output capacitor of GaN components. The results show that the expected robust soft switching is realized when the output power changes.