Simultaneous Wireless Power Transfer and Communications by Recycling Third Harmonics for WPAN Applications

Conventional signal splitting techniques applied in SWIPT, such as time-splitting and power-splitting, suffer from information loss or wasted energy. In this paper, a compact coupler-rectifier-receiver (CRR) system is proposed to address the problems inherent in these conventional techniques. Due to the intrinsic non-linearity of diodes, high-order harmonics are generated as part of the rectification process. Instead of eliminating these harmonics, the proposed structure couples the 3rd harmonic to its isolation port and used it for data recovery. The proposed method is validated by both simulation and measurement. The measured RF-to-DC conversion efficiency (PCE) is over 40% for input powers from - 11 dBm to - 1 dBm and reaches a maximum value of 57.3% at - 4 dBm. Simulation results on 3rd harmonic detection verify its potential for data recovery. Thus, this CRR system is feasible for SWIPT.