Ultra⁃Low Power HighEfficiency UHFBand Wireless Energy Harvesting Circuit Design and Experiment

[Abstract] In this paper, an ultra⁃low power high⁃efficiency ultra⁃high frequency (UHF)⁃band wireless energy harvesting circuit based on the diode SMS7360 is designed and experimentally demonstrated, being operated in all released Global System for Mobile Communications (GSM) bands in China (GSM900 band: 0.87-0.96 GHz and GSM1800 band: 1.71-1.86 GHz). This UHF⁃band wireless energy harvesting circuit can harvest energy at 0.87-0.96 GHz and 1.71-1.86 GHz bands simultaneously in outdoor or indoor environment. The test results show that a radio⁃frequency (RF)⁃to⁃direct⁃current (DC) conversion efficiency in the range of 20%-63.2% is obtained for an available input power of -22 dBm to 1 dBm in GSM900 band and that in the range of 13.8%-55.5% is achieved for an available input power of -22 dBm to 3 dBm in GSM1800 band. The harvested RF energy is converted into DC energy and be stored in a 6.8 mF super capacitor through the energy management circuit. This super capacitor’s capacity is more than 20 mJ, which can meet the demand of high⁃speed broadband wireless communication transceivers. This ultra⁃low power high⁃efficiency UHF⁃band wireless energy harvesting circuit could be used to achieve the low power wireless sensor network node (tag).

[Keywords] GSM900; GSM1800; rectifier; RF energy harvesting; wireless sensor network