An Efficient RF Energy Harvester with Tuned Matching Circuit

Abstract

Microstrip line with π matching circuits are very attractive because of high output power and good impedance matching which makes it an alternative over earlier matching circuit. This paper presents an RF energy harvester with microstrip line in series with tuned π-matching circuit that enables efficient power conversion at different RF input power under different load conditions. Matching circuit parameters were optimized for better efficiency. We have focused for specific input power range -15 to 10dBm for 3-stage, 5-stage and 7-stage of energy harvesting circuit. Optimum efficiency of approximately 80% is achieved at input power 0 to 10dBm for higher stages. Effect of load variation also shows that better efficiency is achieved for input power -10 to 10dBm for 3-stage, 5-stage and 7-stage of the harvesting circuit.