A Batteryless Power Management Unit for RF Energy Harvesting Sensors

We propose a RF energy harvesting system implemented in the 180nm CMOS technology that operates at 915 MHz ISM band. A system is designed to optimize the overall power conversion efficiency (PCE) within the input power range from -30 dBm to 0 dBm. The elements of the tunable matching network are selected based on the derived rectifier model. The dual-channel rectifier, including two Dickson rectifiers, is designed to achieve 64% power conversion efficiency (PCE) across the input power range. A power management unit (PMU), optimized for the operation modes of RF sensors, enables system to achieves 92% efficiency at -13 dBm. The end-to-end RF energy harvester (RFEH) PCE reaches 25.09% at the same input power.