Performance comparison of Differential Evolution, Genetic Algorithm and Particle Swarm Optimization in impedance matching of aperture coupled microstrip antennas

Microstrip antennas are most widely used nowadays for microwave applications because of their numerous advantages like small size and weight, conformability, compatibility with microwave integrated circuits etc. The aperture coupled microstrip line feeding technique has many advantages like availability of a large number of adjustable parameters in the form of aperture length, width and stub parameters. Design of aperture coupled microstrip antennas using a recently developed very fast optimization algorithm namely Differential Evolution [1] is proposed in this paper. The optimization algorithm is used to determine the dimensions as well as the transmission line feed positions for optimum matching over a given range of frequencies and substrate. For use of Differential Evolution in the optimal design of aperture coupled microstrip antennas, the fitness function is evaluated using the Method of Moments technique implemented through IE3D. In addition optimal design of the antenna using other conventional optimization techniques like real coded Genetic Algorithm and Particle Swarm Optimization are done and the results and performances are compared with those obtained by Differential Evolution (DE).