LAUSR

A compact circularly polarized (CP) rectenna based on wide-slot antenna is designed at 5.8 GHz. The feedback wide-slot antenna is used for its broad band, easy-to-integrate circuitry, simple structure, and low sidelobes. The designed receiving antenna has a bandwidth of 31.8%. In order to minimize the profile of the rectenna, the rectifier is integrated on the back side of the substrate with a matching circuit and a dc-pass filter. It features stable conversion efficiency on three azimuthal planes. The maximum efficiency of 66.2% and an output dc voltage of 6.33 V have been measured with a 900 Ω load at the power density of 11.4 mW/cm2. A 5 × 5 rectenna array is built for large physical aperture and increased output power. The maximum conversion efficiency of 62% is observed with the array. Taking the advantage of immunity to misalignment of the CP antenna, the proposed rectenna and array are suitable to be used in mobile applications for wireless power transfer.