Analytical modeling of a printed-circuit tensor impedance surface

Analysis of a printed-circuit tensor impedance surface is presented. The printed-circuit 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, and its dispersion equation is found. In addition, a method for extracting the tensor sheet impedance of an arbitrarily patterned metallic cladding is reported. The extraction method involves performing two normal-incidence scattering simulations with a full-wave solver, and does not require prior knowledge of the principle axes of the surface. By combining the tensor sheet 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.