Dispersion of surface waves supported by truncated metasurfaces

The effects introduced in the dispersion of surface waves supported by a metasurface consisting of a negligible thickness perfectly conducting screen perforated with a finite array of slots are studied by means of a very efficient implementation of Galerkin's version of the Method of Moments with a Delta-Gap excitation. A family of higher frequency modes each of which is periodically repeated in the momentum spectrum with decreasing amplitude is found in contrast to the single mode dispersion obtained for an infinite array.