Equivalent Circuit Model of Frequency Selective Surfaces Embedded in Non-homogeneous Dielectric Slab

In this article equivalent circuit model of frequency selective surface (FSS) embedded within a multilayered slab is investigated. The slab and FSS are supposed to be lossless and therefore the equivalent circuit model of FSS is consisted of purely imaginary elements. First, a square patch FSS is considered in free space and values of inductance and capacitance elements are obtained by Genetic Algorithm (GA) from reflection response in a wide frequency band. Then this FSS embedded within a non-homogeneous multilayer dielectric slab is simulated. A mathematical formula is obtained to calculate the capacitance of FSS from the capacitance of FSS in free space and relative permittivity and thickness of each layer. It is shown that the circuit model based on this formula can obey the simulation results with good agreement.