Rectifier Optimization for Low-Power RF Energy Harvesting Tags

An optimization technique is proposed for the design of highly efficient radio frequency (RF) rectifiers at low power levels. Therefore, a "Thru-Reflect-Line" calibration kit is designed and used for the de-embedding of the SMS7630-005LF series pair Schottky diodes. Based on these measurements an accurate equivalent circuit is proposed, including all parasitic losses that are introduced from the package and the interconnects in the actual application. This equivalent model is used to design a compact and low-cost rectifier for operation in the 2.45 GHz band. This rectifier employs a lumped component L-type matching network and achieves a power conversion efficiency of 13% and 35% at -20 dBm and -10 dBm, respectively. The proposed rectifier can be seamlessly integrated in active radio frequency identification (RFID) tags to extend their lifetime and improve their performance.