Four-switch Class-PN Power Amplifier for High Power Handling Capability in Wireless Power Transfer

Most power amplifiers (PA) for wireless power transfer (WPT) are based on single switch topologies (Class- mathbf{E}, mathbf{F}, Phi,). Single-switch topologies are easy to design and operate, but they are limited in power handling capability. Utilizing multi-switch topologies increases device utilization which improves power handling capability. In this paper a novel topology is introduced, which is referred as Class-PN. Class-PN is based on four switches, and is shown to have more than 6x higher power handling capability than Class-E. The topology consists of no resonating passive components, thus the same PA is operational at multiple switching frequencies. Series resonating load at output power of 135W and switching frequency of both 7MHz and 12MHz are shown at first to verify operation of Class-PN power amplifier. Finally, inductively coupled coils are used to transfer power wirelessly between the transmission and receiving coil. Wireless power delivered to the load at 6.15MHz of switching frequency is 400W, which was limited by the radio frequency (RF) load.