A compact array with low mutual coupling using defected ground structures

A modified ground plane structure that can enhance the performance of the closely packed radiating elements is proposed and studied in this paper. The structure consists of a two element square patch array having defected ground structure (DGS). Two different classes of DGSs were used (i) to reduce the size of the whole array and (ii) to reduce the mutual coupling between the radiating elements. Size reduction of approximately 26% and at the same time mutual coupling reduction of about 12dB was achieved with 0.5 λ
₀
spacing between the radiating elements at the center frequency of 5.25 GHz. A bandwidth of 235MHz was obtained, making it suitable for WLAN applications. Although developed for a 2-element array, the developed principle can easily be extended for larger arrays.