RF Energy Harvesting for Low Power Devices

Abstract

Radio Frequency is abundandly available in an outdoor environment. The number of existing RF bands is impulsive. The RF circuit has to harvest all the potential RF energy present and cannot be premeditated for a specific RF tone. The designed rectenna adds powers coming from an limiteless number of sub frequency bands. The designed rectenna output voltage increase with the number of RF bands. As an application, a Radio Frequency band rectenna is designed. The system uses PIFA (Planar Inverted F Antenna) to harvests energy from GSM900 (Global System for Mobile Communications) ,GSM1800, UMTS (Universal Mobile Telecommunication Service) and WiFi bands simultaneously. The planar inverted F antenna is popular for portable devices because of its low profile, small size, and built-in structure. The radiated power from the antenna is given as input to the rectifier. The schottky diode is used for rectification. Inorder to get maximum power to the load the T matching is used to get an proper impedance matching. The seven stage voltage doubler of HSMS 2850 is introduced in the circuit in order to get maximum voltage to supply the low power devices.