RF Energy Harvesting Circuit for Vital Sensing Platform

This paper presents the design and fabrication of the RF energy harvesting circuit which obtain more than 2 V DC output from the RF power injected from the 900 MHz band RF ID tag transmitter. Our proposed RF energy harvester is composed of a planar antenna, impedance matching circuit and stacked rectifiers. By using this output power, the data of the surface temperature and humidity on the human body are transmitted to the smart phone or laptop PC through the BLE (Bluetooth low energy) module without any batteries.