analysis of stacked structures composed of arrays of thick slits: an accurate analytical circuit model

In this paper, a stacked structure composed of periodic arrays of one-dimensional thick slits embedded in a conventional dielectric medium is investigated in the subwavelength regime. arrays of thick slits are known to support extraordinary transmission resonances. when periodically embedded in multilayered structures, they demonstrate band gap properties, which can produce flat passband regions in some structures, applicable to filter designs. in addition, by adjusting the parameters of the structures, they can be designed to create epsilon-near-zero and negative permittivity metamaterials. the analysis is carried out based on a simple and accurate analytical solution. the employed circuit model includes a transmission line corresponding to the slits, terminated by two surface admittances at the interfaces. the surface admittances assume the role of the diffractive modes and dominate the limitations of the usual analytical surface admittances obtained through heuristic approaches. a π network of lumped elements equivalent to this circuit model is introduced in the present paper. this network helps to find the source of extraordinary resonances. finally, the electromagnetic wave transmission through the stacked structure is studied and the effects of the thickness of the slits and dielectric slabs on the transmission spectra are analyzed. the results are compared to those obtained by full wave simulations, showing good agreement.