Enhanced RF to DC CMOS rectifier with capacitor-bootstrapped transistor

This paper presents a high efficient multi-stages full-wave RF to DC rectifier for RFID applications. The proposed converter employs diode-connected transistors with gate to drain bootstrapping capacitor to overcome threshold drop of voltage. Rectifying transistors are biased in triode region to improve the driving capability of the circuit while they operate at lower input voltages. Bulk biasing technique is applied to ensure faster turn on for level shifting transistors. Simulation results in 90nm CMOS technology at frequency of 920MHz, show that output voltage and power conversion efficiency at low input power level are improved compare to conventional rectifier using diode-connected transistors.