Derivation of Canonical Equivalent Circuits for Multiresonant FSSs with Cross Polarization

We extend our previous formulation for frequency-selective surfaces to the general case with cross polarization and derive the topology and circuit elements of the equivalent two-port network. A canonical Foster representation of the network, together with semi-analytical formulas for all circuit elements, could be obtained by using the resonant current profiles as basis functions for the unknown surface current at the FSS metallizations. For comparison purposes, we have also implemented a standard method of moments (MoM) for the analysis of this structure. A very good agreement has been obtained between the MoM results and the values calculated from the proposed frequency-dependent Foster network for both the co- and cross-polar components, thus validating the proposed procedure.