RF Energy Harvesting For Self Powered Sensor Platform

Abstract

This work demonstrates a RF powered sensor platform where energy can be available either in ambient FM band or emitted from a dedicated RF source. We realized the requirement with a dedicated chip built for RF power harvesting and conditioning. A switched capacitor based ultra low power DC-DC boost converter is designed in 130nm CMOS technology as energy harvesting circuitry for ambient RF. The on-chip RF-DC resulted in a maximum efficiency of 44% with 9.75k resistive load. At input sensitivities of -16dBm over 8 dominant frequencies, the sensor platform with strain gauge as sensor advertised a BLE packet every 20 minutes. For dedicated emitted radiations, the designed hybrid system is powered using sub-1 GHz frequencies. The resulting system has an end-to-end system efficiency of 9.1% and packet transmission interval of 90 seconds.