A Compact RF Energy Harvesting Wireless Sensor Node with an Energy Intensity Adaptive Management Algorithm

• Published in: Sensors (Basel, Switzerland) Switzerland), 2023-10, Vol.23 (20), p.8641
• Main Authors: Liu, Xiaoqiang, Li, Mingxue, Chen, Xinkai, Zhao, Yiheng, Xiao, Liyi, Zhang, Yufeng
• Format: Article
• Language: English
• Subjects: Algorithms; Antennas; Antennas (Electronics); Circuit printing; compact design; Design; Efficiency; Electric power production; Energy management; Energy resources; Mathematical models; Printed circuits; Radiation; Radio frequency; rectenna; RF energy harvesting; Sensors; WSN
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s23208641

This paper presents a compact RF energy harvesting wireless sensor node with the antenna, rectifier, energy management circuits, and load integrated on a single printed circuit board and a total size of 53 mm × 59.77 mm × 4.5 mm. By etching rectangular slots in the radiation patch, the antenna area is reduced by 13.9%. The antenna is tested to have an S11 of −24.9 dB at 2.437 GHz and a maximum gain of 4.8 dBi. The rectifier has a maximum RF-to-DC conversion efficiency of 52.53% at 7 dBm input energy. The proposed WSN can achieve self-powered operation at a distance of 13.4 m from the transmitter source. To enhance the conversion efficiency under different input energy densities, this paper establishes an energy model for two operating modes and proposes an energy-intensity adaptive management algorithm. The experiments demonstrated that the proposed WSN can effectively distinguish between the two operating modes based on input energy intensity and realize efficient energy management.