Push-Pull Class Φ2 Amplifier with Optimized Operation Strategy for High-frequency Wireless Power Transfer System

This paper proposes an operation strategy for achieving high efficiency in a wide output power range of a push-pull class Φ2 amplifier. The proposed operation strategy can utilize push-pull mode and single-ended mode according to the output power. Since the circuit must be able to operate stably in both operation modes, there are additional design requirements. This strategy can improve efficiency under low output power conditions. The proposed operation strategy is verified through an experiment using an 80W WPT transmitter prototype circuit.