Synthesis of high-impedance FSSs using genetic algorithms

In this paper, a genetic algorithm-based technique for synthesizing high impedance surfaces is presented. These surfaces behave like a perfect magnetic conductor (PMC) in a certain frequency range; to achieve this result, a multilayered dielectric structure in conjunction with an FSS screen and a perfectly electric conductor (PEC) ground plane have been used. The genetic algorithm (GA) uses an electromagnetic solver based on the method of moments (MoM) to evaluate transmission and reflection properties of the structure. In particular, the GA determines the shape and the dimensions of the FSS screen, the permittivity and the thickness of each dielectric layer. To improve the speed of convergence of the GA, new selection and mutation strategies have been applied. The synthesized structures show the desired frequency properties and are robust as concerns the stability of the solution with respect to the angle of illumination.