Design and implementation of class E power amplifier with parallel circuit for wireless power transfer systems

This article proposes the design and implementation of the class E power amplifier with parallel circuit for wireless power transfer systems. The high power efficiency of the class E power amplifier with parallel circuit provides small circuit by reducing cooling systems and using low inductance of a DC-feed inductor. Furthermore, the parallel circuit provides wideband operating frequency that makes more flexible to design the resonant capacitors and the coupling coils to transmit and receive the electrical power in the wireless power transfer systems. The proposed class E power amplifier with parallel circuit is implemented with the wireless power transfer system that provides 63% of the maximum power efficiency, 40 dBm of output power and 63 volts of the load voltage for 400 ohms of the load resistance at 2 cm of the distance for transferring power at 160 kHz of the input signal frequency. For the broadband performance of the system, 50% of the power efficiency and 35 dBm of the output power can be maintained the operating frequency from 140 kHz to 220 kHz with the distance that is lower than 5 cm and 400 ohms of the load resistance.