Effective medium modeling method for gridded square loop FSS

This paper presents an effective medium modeling method for frequency selective surface (FSS). The proposed method only retrieves the electromagnetic parameters of the effective medium once, then the reflection/transmission coefficients under arbitrary incidence can be calculated. Compared with previous works, the proposed method reduces the modeling and calculation time by equating the complex FSS to single-layer or multi-layer dielectric slabs. For verification, we built an effective medium model for gridded square loop FSS and obtained a modeling empirical formula. The calculated results are in good agreement with CST and better than the equivalent circuit method.