Compact filtenna with defected ground structure for wireless power transfer application

A compact proximity coupled high harmonic rejection filtenna is presented in this paper. The proposed structure operates in the unlicensed 2.45GHz Industrial, Scientific and Medical (ISM) band. A circular ring slot has been built-in on the ground plane parallel to circular patch, resulting in a 45% reduction area of patch element area as compared to conventional designs. Unique U-shaped slot arrangements are created on the ground plane parallel to the transmission line feed as defected ground structures (DGS) to achieve rejection of higher harmonics. Acceptable suppression of the second and third harmonics is achieved with minimum reflection coefficients of -4.1 dB and -1.8 dB respectively. The proposed design shows good potential for implementation in wireless power transfer and radio frequency energy harvesting infrastructure.