Thin composite matched impedance magneto-dielectric metamaterial absorbers

Low loss magneto-dielectric substrates when used as substrates for patch antennas are shown to miniaturize the aperture size of the patch antennas while preserving or improving the operational bandwidth [1]. In [2], we demonstrated that the properties of a PEC backed low loss matched impedance magneto-dielectric metamaterial slab with frequency dependent permittivity and permeability could effectively be achieved using a multi-layered thin composite structure. In this paper, we demonstrate that modified equations from [2] can be used to optimize thin composite structures to design high loss matched impedance magneto-dielectric metamaterials for absorber applications above 1 GHz. The design technique is based on using a genetic algorithm (GA) to optimize thin multi-layered metallo-dielectric metamaterial slab comprised of a periodic array of electrically small metallic frequency selective surface (FSS) screen sandwiched between two different dielectric materials, one of which is backed by a perfectly conducting ground plane. Examples will be presented to demonstrate the effectiveness of the optimized absorber structures.