Surrogate modeling techniques for frequency-selective surfaces and metamaterials design

In this paper we propose a method based on the Kriging surrogate modeling technique for the generation of a multi response model which determines the correspondence between the RCLG values of a generalized transmission line and the geometrical features (dimensions) of a specific frequency selective surface (FSS) or metamaterial structure (MTM) operating within predefined frequency ranges. In the past forty years there has been an extensive research to generalize transmission line (TL) models for FSS and recently also for metamaterials. Nevertheless, given the complexity of the phenomena involved, the equivalence of the TL-model with a specific FSS or metamaterial structure, in the majority of the cases, can be found only for simple geometries and single layer material systems. In most instances the equivalence is also limited to the case of perpendicular incidence and to specific polarization angles. The method presented in this paper is meant to overcome these difficulties. In a most generalized form, the method is proposed for the design and optimization of periodic sub-wavelength structures in the general case of arbitrary incidence and polarization angles as well as for multilayer material systems. An example of design of a metamaterial structure by using the proposed method will be analyzed and future work discussed.