Class-DEM Tuned Power Amplifier

This paper proposes a Class-DEM tuned power amplifier. The proposed amplifier achieves zero-voltage switching (ZVS), zero-voltage derivative switching (ZVDS), and zero-current switching (ZCS) at turning-on, and ZVS, ZVDS, ZCS, and zero-current derivative switching at turning-off. Therefore, the switching losses are extremely low, which is suitable for high-frequency operation. Moreover, the switch voltage stress is low, which is no more than its input voltage. A proposed amplifier was designed, built, and tested. The measured power conversion efficiency was 93.2% under the condition of the main input voltage of 46.8 V, the operating frequency of 1 MHz, and the output power of 4.87 W.