Design of a 900 MHz Dual-Mode SWIPT for Low-Power IoT Devices

Hamed Abbasizadeh; Sang Yun Kim; Behnam Samadpoor Rikan; Arash Hejazi; Danial Khan; Young Gun Pu; Keum Cheol Hwang; Youngoo Yang; Dong In Kim; Kang-Yoon Lee

doi:10.3390/s19214676

Design of a 900 MHz Dual-Mode SWIPT for Low-Power IoT Devices

Sensors (Basel). 2019 Oct 28;19(21):4676. doi: 10.3390/s19214676.

Authors

Affiliations

¹ Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, CA 92093, USA. habbasizadeh@ucsd.edu.
² Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. ksy0501@skku.edu.
³ Nanoelectronics Group, Department of Informatics, University of Oslo, 0316 Oslo, Norway. behnam@ifi.uio.no.
⁴ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. arash@skku.edu.
⁵ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. danialkhan@skku.edu.
⁶ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. hara1015@skku.edu.
⁷ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. khwang@skku.edu.
⁸ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. yang09@skku.edu.
⁹ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. dikim@skku.ac.kr.
¹⁰ Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea. klee@skku.edu.

Abstract

This paper presents a duty cycle-based, dual-mode simultaneous wireless information and power transceiver (SWIPT) for Internet of Things (IoT) devices in which a sensor node monitors the received power and adaptively controls the single-tone or multitone communication mode. An adaptive power-splitting (PS) ratio control scheme distributes the received radio frequency (RF) energy between the energy harvesting (EH) path and the information decoding (ID) path. The proposed SWIPT enables the self-powering of an ID transceiver above 20 dBm input power, leading to a battery-free network. The optimized PS ratio of 0.44 enables it to provide sufficient harvested energy for self-powering and energy-neutral operation of the ID transceiver. The ID transceiver can demodulate the amplitude-shift keying (ASK) and the binary phase-shift keying (BPSK) signals. Moreover, for low-input power level, a peak-to-average power ratio (PAPR) scheme based on multitone is also proposed for demodulation of the information-carrying RF signals. Due to the limited power, information is transmitted in uplink by backscatter modulation instead of RF signaling. To validate our proposed SWIPT architecture, a SWIPT printed circuit board (PCB) was designed with a multitone SWIPT board at 900 MHz. The demodulation of multitone by PAPR was verified separately on the PCB. Results showed the measured sensitivity of the SWIPT to be -7 dBm, and the measured peak power efficiency of the RF energy harvester was 69% at 20 dBm input power level. The power consumption of the injection-locked oscillator (ILO)-based phase detection path was 13.6 mW, and it could be supplied from the EH path when the input power level was high. The ID path could demodulate 4-ASK- and BPSK-modulated signals at the same time, thus receiving 3 bits from the demodulation process. Maximum data rate of 4 Mbps was achieved in the measurement.

Keywords: IoT devices; PAPR; RF energy harvester; information decoding; reconfigurable; simultaneous wireless information and power transceiver.