Simultaneous Wireless Power and Data Transfer System with Reconfigurable Load-Independent Class-E Inverter

This paper proposes a high-frequency simultaneous wireless power and data transfer (SWPDT) system featuring a reconfigurable load-independent class-E inverter. By applying the reconfigurable topology, the proposed inverter can alternate between two output-voltage levels. Circuit analysis of the proposed inverter is conducted, and based on the analysis results, we present a design method for the proposed SWPDT system. The proposed design method guarantees the load-independent condition for both output levels. Consequently, the two output AC voltage levels remain constant even under load variations, ensuring successful amplitude shift keying (ASK) demodulation. Additionally, zero-voltage switching (ZVS) operation is achieved for both output voltage levels against load variation, which enhances efficiency at MHz frequencies. A 6.78 MHz, 7.4 W prototype was designed and implemented for experimental verification. Successful data transmission at 200 kbps under different load conditions was confirmed. Additionally, the prototype achieved ZVS despite load changes and achieved 89.5% power-transfer efficiency at the rated load, which proves the effectiveness of the proposed SWPDT system.