Design optimization of an energy harvesting RF-DC conversion circuit operating at 2.45GHz

In this paper, the optimization process of an RF-DC conversion circuit for energy harvesting from 2.45 GHz indoor Wi-Fi signals is discussed. The estimated power from a Wi-Fi router is about 0dBm, and it is expected to turn on an off-the-shelf-low-temperature sensor which has input impedance of 10kOhm. In this research, a series type RF-DC conversion circuit with a Schottky diode, SMS7630 from Skyworks is adopted. To specify the potential maximum RF-DC conversion efficiency, the input power, the load and matching circuit are optimized. As a proof-of-concept, the circuit is investigated and optimized with the relationship between the input power of 9dBm and load resistance of 10kOhm. As a result, the highest conversion efficiency of 72.7% and the maximum output voltage of 1.53V are achieved.