New patch configurations to reduce the mutual coupling in microstrip array antenna

In this paper, concave rectangular and hexagonal patch configurations are simulated and optimized to reduce the mutual coupling and return loss in microstrip array antennas. An enhanced genetic algorithm is employed to minimize the design objectives through optimally computing the design parameters. However, the variation of design parameters leads to an undesirable central frequency shift. To avoid this and keep the resonant frequency constant, a constraint is considered in the optimization procedure. Simulation results show that the design objectives are significantly decreased in the proposed configurations compared with ordinary rectangular patches.