Mutual Coupling Reduction in Patch Antenna Arrays Using a Planar Compact EBG Structure

An important issue in antenna array design is reduction of mutual coupling. In microstrip antennas this reduction can be achieved by using electromagnetic band-gap (EBG) structures. These structures prevent the propagation of surface waves on the substrate of a microstrip antenna array. This paper presents a new configuration of a planar compact electromagnetic bandgap structure to reduce mutual coupling between array elements. First, the bandgap feature of the EBG structure is studied by obtaining the dispersion diagram. Next, the EBG structure is placed between two antennas to reduce the mutual coupling level. Simulation results show that a significant value of mutual coupling reduction, more than 22 dB, can be obtained by using the proposed structure.