Arrays of finite or infinite extent in multilayered media for use as passive frequency-selective surfaces

Passive frequency-selective surfaces consisting of a finite or infinite array of metallic patches embedded in a plane multilayered dielectric medium are investigated. The analysis starts with the exact Green´s function for multilayered media formulated in the spectral domain. The integral equation for the patch currents is solved by the method of moments. For finite arrays, the scattered field is given as a continuous spectrum of plane waves, for infinite periodic arrays, it is nonzero only for discrete angles.