Retro-directive Array Antenna With Parabolic Shape Structure for Short-range Microwave Power Transfer

Demands for wireless power transmission(WPT) technologies have been increasing recently with a significant increase in IoT(Internet of Things) and mobile devices. While these microwave power transmission(MPT) technologies want to be generally used within 10 m, conventional studies have assumed that transmission distance is very long. A retro-directive array structure can be used for microwave power transmission in the Fresnel region. The parabolic shape structure is proposed for higher efficiency of microwave power transmission. The parabolic shape structure is arranged to have the same phase from the receiver. The efficiency of microwave power transmission in the receiver is higher than that of the equi-phased array and retro-directive array of linear structure. In addition, the power distribution analysis is performed with regard to the location of the equi-phased array, the retro-directive array, and the retro-directive array with a parabolic shape structure.