Planar rectennas for 2.45 GHz wireless power transfer

Three planar rectennas (rectifying antennas) on different PCB materials have been designed. Patch antennas were designed with a MoM (method of moments)-based simulator while in RF-to-DC conversion circuits microstrip and discrete rectifier diode models were utilized in circuit simulations. The goal was to achieve maximum antenna and conversion efficiency at the desired reception power level. 80% antenna efficiency and 70% conversion efficiency was achieved in simulations. The terms for achieving a sufficient reception power level were considered and compared to the performance of the designed antennas. The accuracy requirements for the realization of these rectenna structures were also defined with the aid of both simulation and measurement results.