Circuit approach for a general study of frequency selective surfaces

This paper presents an equivalent circuit approach to study the scattering characteristics of frequency selective surfaces (FSS). The derivation of this equivalent circuit comes from the recognition of a minimal-order configuration that accounts for the interaction of the impinging plane wave with the higher-order Floquet harmonics excited by the periodically repeated unit cell. Key in this approach is to find the appropriate connection of the different transmission lines that model the above interaction.