5.8-GHz planar hybrid rectenna for wireless powered applications

This paper presents a high-efficiency low-reradiation planar rectifying antenna (rectenna). The rectenna is composed of a high-gain cavity-backed circular patch antenna using novel coplanar feeding structure and a low-profile microstrip rectifying circuit. The cavity-backed antenna achieved the gain of 9.17dBi and the -20dB return loss bandwidth of approximately 1.4%. The rectifying circuit has a harmonics filter that suppresses the reradiated harmonics under -59 dBc. The RF-to-dc conversion efficiency of the rectenna element was measured as 71.4% with a 266mW input power. Over 13W DC output power was demonstrated using the 52- element triangular array.