Bandwidth improvement of parasitic coupled patch antenna with Genetic Algorithm

Patch antennas with parasitic subarrays are used to improve the bandwidth of the patch antennas. Parasitic subarrays are coupled to radiating edges, nonradiating edges or all four edges of the patch. These subarrays create new resonance frequencies which interfere with the main resonance frequency and improve the bandwidth. Gupta et al. [1] used segmentation method to optimize the gap dimensions and parasitic patch dimensions to obtain bandwidth as large as 10%. In this paper we set gap coupling and parasitic dimensions fixed and use genetic algorithm combined with FDD method for simulation and optimization of the problem. Our goal is to increase return loss bandwidth. Genetic Algorithm (GA) is performed on the parasitic subarrays with no change on the main patch. At each iteration of GA we remove some defined cells form the parasitic patches and simulate the structure to monitor bandwidth width enhancement, Such iteration is performed several times to obtain good bandwidth. Main patch is designed at 9 GHz, and parasitic patches have the same dimension as the main patch. Primary simulations have shown bandwidth improvement more than 10%.