Vector Circuit Theory for Isotropic and Chiral Slabs

Abstract

This paper discusses modelling of isotropic and chiral slabs by using vector circuits involving dyadic impedances and admittances and tangential field components. The analysis is based on the exact averaging method for the Fourier-transformed field equations of the slab. Then, by considering tangential electric and magnetic fields as voltages and currents, analogous vector circuits, such as equivalent two-port circuits, Thévenin and Norton circuits and T and II circuits, are given for isotropic and chiral isotropic and homogeneous and nonhomogeneous slabs. These vector circuits are most appropriate when calculating propagated and reflected fields for general excitation. In addition, different approximations related to slabs thin either in wavenumbers in the normal or in transversal directions or to slabs with different propagation constant ratios are considered. A case when a slab can be simulated by a sheet is also discussed. The results obtained can be useful in many practical situations, for example, for multilayered structures with small differences in parameters of the layers, or, vice versa, for slabs with contrast parameters.