RF energy harvester with peak power conversion efficiency tracking

TitleRF energy harvester with peak power conversion efficiency tracking
Publication TypeConference Proceedings
Year of Conference2016
AuthorsSun, M., D. C. Ranasinghe, and S. F. Al-Sarawi
Conference Name IEEE Asia Pacific Conference on Circuits and Systems (APCCAS)
Date Published2016
Other NumbersDOI:10.1109/APCCAS.2016.7803908

Rectifier circuits or power harvesters are a critical moduleinavarietyofwirelesssensors,radiofrequencyidentification (RFID) tags, and Internet-of-Thing (IoT) devices relying on harvested power from radio waves. The threshold compensation circuit techniques have been proposed in the literature to improve thePowerConversionEfficiency(PCE)ofCMOS-basedrectifiers. However, these circuits are designed to achieve maximum PCE at a specific input power level, and has significantly lower efficiency at other input power levels. In this paper, we propose a novel energy harvester which maximises its PCE over a wide input power range. The proposed design relies on sensing of the rectifier output voltage, management of the output current and reconfiguration of the rectifier. The design, which operates at 915 MHz, is demonstrated through simulations in a 130 nm CMOS process. The simulation results show that the harvester manages to develop a 3 V DC with -25 dBm input power sensitivity and its PCE remains above 60% for 23 dB input power range.