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

Abstract

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.

Development of 2400–2450 MHz Frequency Band RF Energy Harvesting System for Low-Power Device Operation

“…Similarly, a seven-stage full-wave rectifier intended for RFEH applications at 2400 MHz exhibited a measured PCE of 18.6%, coupled with a maximum output voltage of 2 V [20]. Xiaoqiang et al [8] successfully increased the PCE to 52.5% by employing a multi-stage full-wave rectifier, yielding a maximum output voltage of 4.8 V while operating at a resonance frequency of 2437 MHz. In this work, the PCE was notably improved by implementing appropriate LC-based impedance matching and employing a two-stage Cockcroft rectifier.…”

“…The RF spectrum spans from very high frequencies (VHFs) to extremely high frequencies (EHFs), covering the range from 3 kHz to 300 GHz within the electromagnetic spectrum. All familiar transmission systems leverage specific segments of the RF spectrum to transmit signals to the receiving end [8]. RF energy is currently being broadcast by millions of transmitters globally.…”