35 GHz harmonic harvesting rectifier for wireless power Transmission

In this paper, a structure of dual diode microstrip rectifier circuit operating at 35 GHz capable of harmonic harvesting is proposed to improve the RF-to-DC conversion efficiency. To do so, the conventional voltage doubler is first modified for 35 GHz operation. Then, a harmonic harvesting rectifier is designed and optimized in order to maximize the RF-to-DC conversion efficiency. Both circuits are fabricated and experimentally tested. Measured efficiency of 34% for 20 mW RF input power for harmonic harvester model and 23% for the same RF power level for the modified voltage doubler are obtained. Results of the harmonic harvester rectifier suggest about 20% efficiency improvement for medium power range (1 to100 mW) at millimeter-wave frequency compared to previously reported designs. The proposed structure can find potential applications in the design of millimeter-wave wireless power transmission and energy harvesting devices.