Broadband High-Efficiency RF Rectifier with a Cross-Shaped Match Stub of Two One-Eighth-Wavelength Transmission Lines

This paper presented a broadband rectifier that can be applied to harvest ambient radio-frequency (RF) energy. The matching network consists of three-stage transmission lines. A cross-shaped match stub of two one-eighth-wavelength transmission lines is proposed to realize efficient and broadband impedance compression. The proposed circuit has been optimized and manufactured, and the measured results show that the rectifier can achieve high RF-to-DC conversion efficiency and broadband characteristics. The simulation and measured results were basically consistent. When the input power is 8 dBm and the terminal load is 1.6 kΩ, a bandwidth of 81% (1-2.35 GHz) with an efficiency above 50% and a bandwidth 69% (1-2.05 GHz) with an efficiency above 60% are achieved. The highest conversion efficiency of the test circuit is up to 73.2% at an input power of 8 dBm. Moreover, when the input power changes from 1 to 11 dBm, the efficiency of the rectifier circuit is always above 50%.