Class-E Power Amplifier Design for Wireless Power Transfer

This paper presents the design of a Class E power amplifier for wireless power transfer applications. The amplifier is designed for a switching frequency of 100 kHz and an output power of 15 W, adhering to Qi standards. For wireless power transfer, a series-series topology was found to be suitable. To achieve Zero Voltage Switching (ZVS), the primary side of the series-series topology was tuned to a frequency slightly lower than the switching frequency. This eliminates the need for an additional inductor, making the overall system more compact. Since deviating from the resonant frequency can affect the power transfer capability of the wireless power transfer system, the secondary was tuned to a resonant frequency equal to the switching frequency. The targeted application is consumer electronics, such as cell phone chargers.