Modeling of plasmonic coatings in RCS computations

As far as RADAR Cross Section (RCS) computations are concerned, meshing inclusions much smaller than the wavelength of interest λ to model microscopic details often leads to untractable problems when target dimensions are much greater than λ. Consequently equivalent material parameters are necessary, and they can be derived from “effective medium approximations” (EMA). In this work we focus on EMA introduced by Pendry et al. (“Mimicking surface plasmons with structured surfaces”, Science, vol. 305, p. 847, 2004) and further investigated by Garcia-Vidal et al. (“Surfaces with holes in them: new plasmonic metamaterials”, Journal of Optics A, vol. 7, p. S97–S101, 2005) in relation with perfect electrical conductors perforated with grooves. The EMA anisotropic dielectric permittivity can be deduced from extended Bruggeman theory. The EMA magnetic permeability must be modified to correct the effective index: the product εμ is forced to be equal to 1 so as to ensure a correct phase velocity in the grooves.