Methods for Improving the Efficiency of Transcutaneous Wireless Power Transmission Systems Using a Class E Power Amplifier

This article investigates circuit techniques for improving the efficiency of a transcutaneous wireless power (TWP) transmission system based on a class E power amplifier. The results of comparing a system with a standard class E power amplifier with three possible amplifier modifications are presented: addition of a series filter to the amplifier, addition of a parallel filter to the amplifier, and use of an amplifier with semi-resonant topology. All circuits were designed in such a way that the condition of switching at zero voltage is met, and all provide the same output power of 1 W. The system with a class E power amplifier with semi-resonant topology was found to have the highest efficiency - 78.2% - for a TWP system with parameters typical of those of the power supplies of implantable medical devices.