Shaping of the flat-topped element patterns in arrays of stepped horns with dielectric protrusions excited by TEM waves

A 2D problem of an infinite periodic array of stepped horns excited by TEM waves is considered. The array comprises narrow dielectric elements passing through the horns and protruding above the horn apertures. A hybrid algorithm of solution applying projective mode-matching over the transverse coordinate and one-dimensional finite element method over the longitudinal coordinate is developed. Some new numerical results for the array reflection coefficient and element pattern characterizing both the method of solution itself and capabilities of shaping the sector patterns by the horn-dielectric elements are presented and discussed.