Plane-wave Scattring Analysis of Artificial Anisotropic Dielectric Sandwiched by Metallic Cross-dipoles Grating

摘要

Double-screen metallic grating with artificial anisotropic dielectric is analytically and experimentally studied. The artificial dielectrics are composed of two alternating isotropic dielectrics. Proper choosing of these dielectric constant leads to realizing tunable uni-/biaxial anisotropic media. Such an artificial anisotropic medium is employed as a substrate of a double-screen grating composed of cross-dipoles patches. The optic axis of this artificial anisotropic material is perpendicular to the metallic grating's period due to its more complicated analysis. Scattering of plane-waves by such a structure is analyzed by Galerkin's Method of Moments (MoM). In this analysis, the dyadic Green's function is evaluated by a Fourier-domain model of Transmission Line (TL). Using MoM-TL technique, the induced currents on patches and electromagnetic field distributions are calculated. It is shown that by suitable choosing of their structural parameters, one can obtain tunable frequency filter. To validate the analytical results, a double-screen metallic cross-dipoles grating with an artificial uniaxial anisotropic substrate is fabricated and measured.