An Equivalent Circuit Model to Interpret The Coupling Between FSS Layers

An equivalent circuit model to explain the coupling between FSS (frequency selective surface) is presented in this paper. The proposed method of establishing equivalent circuit models is suitable for the modeling of multi-layer FSSs and has higher rationality and accuracy than the most existing methods that do not consider coupling. Meanwhile, empirical equations are proposed to build the relationship between the coupling coefficients and the distance between layers. By using the empirical equations, the transmission/reflection coefficients of the FSS structure can be obtained directly without full-wave simulations. Simulations show that these equations are still valid when the size of the unit cells is changed.