EFFICIENT COMPUTATION OF GENERALIZED SCATTERING MATRIX FOR ANALYZING MULTILAYERED PERIODIC STRUCTURES

An efficient technique is proposed for the computation of the generali zed scattering matrix (GSM) of a dielectric interface with periodic me tallizations. The technique is based on a spectral domain moment metho d, but assuming multiple incident Floquet-harmonics and computing the GSM directly, Also, some symmetry properties are exploited, and the wh ole GSM is computed with similar computer effort as that required for a single scattering coefficient, The technique has been applied to the analysis of periodic surfaces involving rectangular and arbitrarily-s haped metallizations using entire- and sub-domain basis functions, res pectively. Losses in both dielectric layers and metallizations have be en included in the formulation. Multilayered periodic structures are a nalyzed in a very flexible and efficient way by cascading iteratively the GSM of each interface with or without metallizations considered as building blocks, Numerical results have been provided for different m ultilayered structures, and a good agreement with other experimental a nd theoretical data has been obtained, The proposed technique is very appropriate for the analysis of composite structures when the separati on between interfaces is small, and therefore higher-order Floquet-har monic interaction cannot be neglected.