A Study on a Rectenna for Low Power Density at 2.45 GHz

This paper presents a study on a rectenna for rectification of incident low power microwave signals with power densities less than 2 mW/ at 2.45 GHz. The proposed rectenna is designed and implemented by a rectifier with voltage doubler structure and a printed Yagi antenna which suppress re-radiation of the second order harmonic of fundamental frequency. The printed Yagi antenna has a gain of about 5 dB, and the measured conversion efficiencies of the rectenna are from 32 % to 42 % when its incident power levels are from 0 dBm to 14 dBm. The developed rectenna is expected to be useful in the power transmission system.