A Design of Peak to Average Power Ratio Based SWIPT System in 180 nm CMOS Process for IoT Sensor Applications

Abstract

In this paper, we propose a peak-to-average-ratio (PAPR) based simultaneous wireless information and power transfer (SWIPT) system for Internet-of-Things (IoT) sensor applications. Conventional SWIPT system is based on power-hungry transmitter and receiver modules. The presence of such blocks directly impact the power consumption in IoT devices. This problem can be solved by proposing an ultra-low-power communication mechanism. Recently SWIPT with multi-tone is under consideration because of its increased power conversion efficiency (PCE). We proposed a PAPR based SWIPT receiver that utilizes the multi-tone waveform for information decoding in SWIPT system. An adaptive power splitter (APS) smartly regulates the distribution of received radio frequency (RF) signals between the energy harvesting (EH) path and the information decoding (ID) path. A digital controller was designed to control the demodulation of the PAPR based modulated signal and retrieves the digital information. Back-scattering modulation has been opted for up-link data transfer. For the EH path we design an RF-DC converter with an adaptive matching to increase the dynamic range of input power. The propose SWIPT system based on the PAPR demodulator is implemented on the 180 nm CMOS process. The digital clock frequency at the SWIPT receiver is 64 kHz, which can provide a data rate of 8 kbps with power consumption of $7.3~\mu \text{W}$ with area utilization of 0.4 mm2.

Keywords

• Energy harvesting
• information decoding
• multi-tone
• peak to average power ratio
• simultaneous wireless information and power transfer