Self-adapting Impedance Matching Circuit for UHF RF Energy Harvester

In this paper, a fully passive RF Energy Harvester is presented, to be used in the UHF band. The system includes an antenna, a Dynamic Impedance Matching Network (DyIMN), a diode-based voltage rectifier and multiplier, a micropower DC/DC converter circuit, a storage capacitor and the load electronic, comprising the MCU. The DyMN is comprised of varactors that dynamically change their junction capacitance, controlled by an MCU, allowing the impedance tuning of the matching stage between antenna and rectifier.