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

This article 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. In addition, the 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 kb/s under different load conditions was confirmed. In addition, 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.