Dispersion analysis of printed-circuit tensor impedance surfaces

Dispersion analysis of a printed-circuit tensor impedance surface is presented. The tensor impedance surface consists of a periodic, subwavelength-patterned metallic cladding over a grounded dielectric substrate. It is analytically modeled as a tensor sheet impedance over a grounded dielectric substrate. Its dispersion equation and an expression for the group velocity are found. In addition, a method for extracting the tensor sheet impedance of an arbitrarily patterned metallic cladding using a full-wave solver is reported. By combining the extraction method with the dispersion equation, the full dispersion characteristics of the periodic structure can be analytically predicted within the homogenous limit. The results are verified through full-wave eigenmode simulation.