Conical horn antenna having a mode generator

摘要

A conical horn antenna is disclosed having dual dielectric bands mounted therein for improving the rotational symmetry or elipticity of the radiated beam as well as the efficiency. The first and second dielectric bands are coaxially mounted to each other and to the conical horn. The lengths of the bands are determined by the frequencies being propagated. A circularly polarized dominant wave such as TE11 mode is applied to the antenna and excites a series of higher order waves such as the TM11 mode. The circularly polarized dominant and the higher order modes are propagated toward the aperture where they are in phase and therefore add vectorially. The dual dielectric band acts as a slow wave structure and higher order waves which in turn provide an improved phasing between the dominant modes.