Scattering by multilayered periodic structures containing asymmetric dielectric and metallic components

Studies of wave scattering by structures that exhibit a multilayered geometry along the vertical axis and a periodic variation along the horizontal one have been stimulated by problems relevant to radio-wave propagation in urban environments, light-beam processing in optoelectronic devices, antenna arrays and other areas. However, most studies have considered situations having symmetric periodicity cells only, or asymmetric cells that contain either dielectric or metallic materials, but not both. To explore a wider class of such configurations, we have extended a previously developed modal transmission line approach so that asymmetric cells that include both dielectric and metallic components can now also be treated. The metallic portions are assumed to be perfectly conducting but they can be thick and may have arbitrary forms. Our approach can address structures having any number of layers, but we illustrate it by considering a geometry that models the cross-section of a building wall.