Derivation of Circuit Models with Canonical Topology for Frequency Selective Surfaces with Multiple Resonances

Periodically patterned metallic surfaces have been widely used in Microwave Engineering as well as Optics due to their ability to control the associated scattering by conveniently adjusting their geometrical and structural parameters. Typical examples are diffraction gratings, frequency selective surfaces, and similar structures as partially reflecting surfaces, metasurfaces, etc, which find application in many practical devices like antennas and absorbers. Computational methods for the analysis of these periodic structures are certainly very mature and included in today's most popular commercial electromagnetic simulation software packages. However, a purely numerical analysis can become computationally expensive and most often provides little valuable insight into the physical mechanisms behind the behavior of the structure being studied. Therefore, the development of relatively simple reduced order models is still a worthy effort that can help to overcome some of the disadvantages of the intensive full-wave numerical approaches.