Spectral-domain analysis of a finite frequency-selective surface with cross-shaped conducting patches

The authors consider the problem of a finite frequency-selective surface comprised of cross-shaped elements that are capable of responding to both polarizations of the incident field. A plot of the magnitude of the surface current density along a cut through the center of a five-patch by seven-patch frequency-selective surface is presented. The overlay is the corresponding current of a five-cell-wide frequency-selective surface, which assumes that the structure is infinite along y. The cross-polarized component of the current is greatly enhanced due to the truncation of the surface. The effect of increasing the number of cells in the y direction from 7 to 21 is illustrated. As expected, the agreement between the 21-cell case and the periodic result is much closer than it is for smaller structure.<>