1.9GHz–4.1GHz CMOS Rectifier with Over 48% Efficiency Using Inductive Feedback and CRT Reduction for Beamforming WPT

This letter presents the design of an ultra-wideband half-wave CMOS rectifier with maximum flat efficiency using an inductive feedback technique. First, a diode model for high-frequency rectification is proposed by connecting a small capacitor between the drain and ground terminal to reduce clock recovery time (CRT). Second, maximum flat efficiency over a wide bandwidth is achieved by employing the inductive feedback technique. The proposed design implemented in 0.18 µm CMOS technology achieves more than 48% conversion efficiency at 18 dBm input power in the frequency range from 1.9 GHz to 4.1 GHz, with an active circuit size of 0.5185 mm².