Double layer patch antenna array using novel EBG structure for reducing mutual coupling losses

Electromagnetic BandGap(EBG) structures are used to reduce mutual coupling loss by their ability to suppress surface waves propagation in the specified frequency range. The EBG structures are needed more compact in size since they are to be placed in between the patch antennas. Patch antenna arrays are have been used extensively because of its low profile structure, light weight and low cost. They have many advantages over conventional antennas, which make them suitable for a wide variety of wireless applications. However, major two drawbacks of patch antenna arrays are i. narrow bandwidth, and ii. Antenna size. In this paper, double layer antenna design is proposed in which E-E fork shaped Electromagnetic BandGap (EBG) structure is placed in between the patch antenna. A double layer structure composed of high and low permittivity layers. EBG structures are placed in high permittivity layer where as antenna element is placed in low permittivity layer. Low permittivity layer helps the bandwidth and directivity of the antenna to be increased. Since the EBG seeds and patch antennas placed one above another layer, the size of the antenna device can be reduced significantly. The EBG structure performance is analysed and compared with Double E EBG structure and the proposed EBG structure. Mutual coupling loss is also reduced appreciably with this patch antenna array design.