A 2.45-GHz Rectifier-Booster Regulator With Impedance Matching Converters for Wireless Energy Harvesting

In this paper, a proof-of-concept high-efficiency rectifier-booster regulator (RBR) with an impedance matching converter operating at 2.45 GHz is proposed. An entire WLAN energy harvesting system is demonstrated. A flower-shaped broadband dual-polarized cross dipole antenna with a full-wave matching network is employed to harvest electromagnetic energy from a WiFi router. A novel RBR is proposed to rectify the RF energy to dc and boost the output voltage. It is evolved from a Greinacher rectifier and two Cockcroft-Walton charge pumps to form a full-wave rectifier. An equivalent resistance model is established to evaluate the optimal stage of the RBR. Furthermore, a boost converter is designed as an impedance matching converter to harvest as much energy as possible from the RBR and store the energy into a 1-mF supercapacitor. Experimental results show that the RBR can provide 1.7-V output voltage under -10-dBm input power. In addition, the RBR can achieve up to ×3.4 voltage boosting with 85% voltage conversion rate (VCR) and provide a higher than 1-V output voltage within a distance of 50 cm between an antenna with 20-dBm transmitting power and the rectenna. The excellent performance shows the wide practicality of the proposed design method for the Internetof-Things (IoT) applications.