Simultaneous Wireless Information and Power Transfer (SWIPT) for Internet of Things: Novel Receiver Design and Experimental Validation

In this article, we propose a novel simultaneous wireless information and power transfer (SWIPT) scheme for the Internet of Things (IoT). Different from the conventional power splitting (PS) and time switching (TS) schemes, the proposed scheme sends the wireless power via the unmodulated high-power continuous wave (CW) and transmits information by using a small modulated signal in order to reduce the interference and to enhance the power amplifier efficiency. We design a receiver circuit for processing such SWIPT signals, which is designed with the aim of minimizing the circuit complexity and power consumption for information decoding. This goal is achieved by first rectifying the received signal and then splitting the power and information signals. We analyze the proposed receiver circuit and derive the closed-form expression for the energy harvesting efficiency and the frequency response of the communication signal. We have implemented the proposed receiver circuit and built the real-time testbed for experimenting with simultaneous transmission of information and power. By experiments, we have verified the correctness of the receiver circuit analysis and shown the validity of the proposed SWIPT scheme.