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 wid-ened 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 har-monic rejection characteristics as a low-pass filter. The rectifier network topol-ogy is adopted with a diode in parallel connection to increase the output voltage of the circuit. The reflected power generated by the impedance mis-match 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.

Keywords

• rectifier circuit
• rectifying efficiency
• wireless energy transmission
• yagi antenna