Synthesis of artificial magnetic conductors by using multilayered frequency selective surfaces

In this letter, the combination of a multilayered dielectric structure, a capacitive frequency selective surface (FSS) and a perfectly electric conducting (PEC) ground plane is proposed for realizing high-impedance surfaces. These surfaces behave like an artificial magnetic conductor (AMC) in a specific frequency range; the inclusion of the dielectric layers allows us to enhance the angular properties of the AMC as well as the frequency bandwidth of the device. In order to obtain the proper values of the design parameters, a genetic algorithm (GA) is employed that makes use of an electromagnetic solver based on the method of moments (MoM) to evaluate the scattering properties of the structure. A key step in the design procedure is the inclusion in the fitness function of the electromagnetic response of the high-impedance surface with respect to the illumination angle. The synthesized structure shows the desired frequency performance and reveals robust as concerns the stability of the solution with respect to a wide interval of illumination angles.