Design of high-efficiency rectenna for microwave power wireless transmission systems

Abstract

Radio power transmission is studied herein. A rectenna with high-efficiency microwave power transmission is proposed. Improvement on the traditional Yagi antenna structure is implemented by using a rectenna. In this design, the antenna is fed by a coplanar waveguide, and the impedance bandwidth is widened by adding a set of radiation dipoles. A set of parasitic directors is used to enhance the directionality of the antenna. A rectifier circuit based on a power-recovery network is designed using an open branch-line network with harmonic rejection characteristics as a low-pass filter. The rectifier network topology is adopted with a diode in parallel connection to increase the output voltage of the circuit. The reflected power generated by the impedance mismatch can be recycled by the power-recovery network. Thus, the rectifying efficiency can be improved. Finally, experimental data show that the radiofrequency–direct current power conversion efficiency of the rectenna can be as high as 77.5% at the operating frequency 2.45 GHz and the input power 12 dBm. The proposed rectenna can be potentially used for the power supply of various wireless sensor nodes with high efficiency.