A Dual-Band Rectenna Using Broadband Yagi Antenna Array for Ambient RF Power Harvesting

This letter presents a dual-band rectenna that can harvest ambient RF power of GSM-1800 and UMTS-2100 bands efficiently. The novel rectenna is based on a broadband 1 x 4 quasi-Yagi antenna array with bandwidth from 1.8 to 2.2 GHz and high gains of 10.9 and 13.3 dBi at 1.85 and 2.15 GHz, respectively. Also, a dual-band rectifier that can sufficiently enhance the RF-to-dc power conversion efficiency (PCE) at ambient RF power level is designed for the rectenna. Measurement results show that a PCE of 40% and an output dc voltage of 224 mV have been achieved over a 5-k Omega resistor when the dual-tone input power density is 455 mu W/m(2). Additionally, output dc voltage varying between 300-400 mV can be obtained by collecting the relatively low ambient RF power.