Reduction of mutual coupling between dual-element antennas with new PBG techniques

This paper presents the results of reduction of mutual coupling in closely-packed antennas. The structures include of a simple ground plane and wall that silted pattern etched on a ground plane and the mushroom PBG etched on a wall. It is consequently low cost and simple to fabricate. The isolation of more than -56 dB can be achieved with state-of-the art mushroom PBG loaded on the one wall and with one pair of slit between two parallel microstrip patch antennas; inter-antenna spacing (center to center) is 0.272 lambda₀. Also we are investigated that with three slits of mushroom PBG on the wall can reduce S12 more than -12 dB. Ground plane size is (0.617 lambda₀ times 0.376 lambda₀). In addition the isolation of -37 db can be achieved between two parallel individual planar inverted-F antennas (PIFAs) sharing ground plane and two walls that the mushroom PBG etched on it.