Reduction of mutual coupling between closely-packed antenna elements using defected ground structure

A simple ground plane structure that can reduce mutual coupling between closely-packed antenna elements is proposed. The structure consists of a dumb-bell-like pattern etched in a single ground plane. It is found that isolation of more than -40 dB can be achieved between two parallel individual planar inverted F antennas sharing a common ground plane. Influence of the designed defected ground plane structure on the radiation pattern is also investigated.