Multi-Stage Rectifier Enabled Battery-Free Sensor Platform Utilizing Ambient RF Energy

Abstract

Ambient radiofrequency (RF) energy harvester scavenges RF power “wastes” and converts them into usable dc output. Considering the limited output of an ambient RF energy harvesting device, this scheme is highly suitable for low-power and low-duty-cycle wireless sensing applications. This work presents a battery-fiee multi-function sensor platform based on a multi-stage rectifier utilizing ambient RF energy. An analytical model with equivalent circuits is developed to analyze and optimize multistage rectifiers. Guided by the theoretical analysis, a 5-stage rectifier is realized. A final experimental demonstration shows that the multi-function sensor platform can sustain itself with the power supply from the 5 -stage rectifier harvesting ambient RF energy at a practical power level.