High-Efficiency CMOS Rectifier Dedicated for Multi-Band Ambient RF Energy Harvesting

Several rectifier topologies dedicated for radio frequency (RF) energy harvesting have been proposed, but only a few have been reported to be able to harvest RF energy at low input power (LIP) levels. In this paper, we are focusing on fully gate cross-coupled (FGCC) rectifier structure, which gives good performance at LIP levels. In order to get an enough high output DC voltage, a 3-stage FGCC rectifier using low-threshold-voltage (LTV) transistors is designed. According to simulation results, with 850MHz input AC signal, the designed rectifier has power conversion efficiency (PCE) of 70% at 20 mu W (-17.0dBm) input power with 100kOhms load. Also, a multi-band RF energy harvesting topology is proposed. Simulation results show that PCE of the tri-channel rectifier achieves 66.3% at 4.8 mu W (-23.2dBm) input power per channel and 1V DC output voltage is generated at 5.1 mu W (-22.9dBm) input power per channel with only 100kOhms load, showing both high-efficiency and sensitivity.