Simultaneous Wireless Power and Information Transfer System With Capacitive Coupler Based on Differential Diplexer

This paper proposes a differential diplexers-based capacitive wireless power and information transfer (WPIT) system for achieving maintenance-free industrial robots. The differential diplexer is designed by combining a high-pass filter (HPF) for 2.45 GHz signals, a low-pass filter (LPF) for 13.56 MHz power transfer, and an LC balun for differential output. Through the incorporation of matching with the capacitive coupler, the diplexer achieves a power transmission efficiency of 93.7% and power isolation of 60 dB. Furthermore, successful demodulation and modulation of 16QAM signals within a 1 MHz bandwidth are demonstrated, resulting in a communication speed of 4 Mbps.