Enhanced Dual-Band Ambient RF Energy Harvesting With Ultra-Wide Power Range

This letter presents a novel dual-band rectifier with extended power range (EPR) and an optimal incident RF power strategy in the settings where the available RF energy fluctuates considerably. It maintains high power conversion efficiency (PCE) in an ultra-wide input power range by adopting a pHEMT in the proposed topology. Simultaneous RF power incident mode is proposed and preferred to the traditional independent mode for multi-band harvesting. Measured results show that more than 30% PCE is obtained with input power ranging from -15 dBm to 20 dBm and peak PCE of 60% is maintained from 5 to 15 dBm. Positive power gain is achieved from -20 dBm to more than 10 dBm. Investigation about the effect of RF power incident ratio on dual-band harvesting´s performance is presented and it provides a good reference for future multi-band harvesting system design.