Low loss dual polarized matched zero index metamaterials for microwave applications

Planar multilayer dual polarized zero index metamaterials using cascaded frequency selective surface screens were presented. Two structures with three and four screens, respectively, were optimized by a genetic algorithm to have a very low effective refractive index and an effective impedance matched to free space. Fabrication constraints on the screen geometry and the dielectric layers were included to guarantee that the design can be correctly fabricated.