Dual-frequency MIMO antennas with reduced mutual coupling

The effect of mutual coupling between array elements has become one of the key factors that significantly affect the performance of multiple antenna systems. In this paper, an efficient technique utilizing the defected ground structure (DGS) to increase the port isolation of a dual-frequency patch antenna array is studied. The proposed dual-frequency DGS beneath between two patches includes two circular split ring slots, each of which corresponds to one resonant frequency of the patches. The simulated results show that the mutual coupling between array elements has been obviously reduced with the implementation of the proposed DGS structure