Effects of chiral loading on a frequency selective surface comprised of a two dimensional array of crossed dipoles

The use of resonant crossed dipoles in forming frequency selective surfaces (FSS) is well known. A FSS comprised of crossed dipoles arranged in a two dimensional array on a dielectric slab behaves as a solid metal reflective surface over a single resonant frequency band when illuminated by a normally incident plane wave. On the other hand, a FSS made up of an array of rings exhibits multiple reflection resonances having narrow bandwidths when the supporting dielectric slab is replaced by an isotropic chiral, slab. In this paper the results obtained in a theoretical investigation is presented of the scattering by a FSS comprised of an infinite array of conducting crossed dipoles arranged in a doubly periodic square grid and backed by a chiral slab. The boundary value problem is formulated by relating the fields scattered from the FSS to the surface currents induced on the crossed dipoles for an arbitrarily polarized plane wave incident from any oblique angle.