A highly efficient tri band (GSM1800, WiFi2400 and WiFi5000) rectifier for various radio frequency harvesting applications

This work focuses on the development of a highly efficient and low threshold tri band rectifier for harvesting DC power from ambient RF signals of GSM1800, WiFi2400 and WiFi5000 bands. A single stage voltage multiplier rectifying topology is used. SMS-7630 schottky diode by Skyworks is used as rectifying element due to its low threshold voltage. The circuit is initially designed on Keysight Advance Design System (ADS) and fabricated on 1.57 mm thick RT/duroid 5880. Multi section impedance transformer along with stubs is used for designing tri band impedance matching. Power levels of interest are from — 30 dBm to 0 dBm. Rectifier is matched for a diverse load range of 5 k to 50 k, which are typical impedances of wireless sensors. RF to DC conversion efficiencies are 54.8%, 45.8% and 20.1% for GSM1800, WiFi2400 and WiFi5000 respectively at a typical power input of — 10 dBm. Peak conversion efficiencies are 67.4%, 57.8% and 39.2% for GSM1800, WiFi2400, and WiFi5000 respectively for — 3 dBm power input. Measurements are in good agreement to the simulated results.