Complete characterization of corrugated elliptical horns for millimeter wave antennas

A novel hybrid "mode matching"-"multiple multipole"-technique is introduced for the analysis of both the internal and the external characteristics of corrugated elliptical horns which are used for illuminating millimeter wave reflector antennas. The method is based on expanding the electromagnetic field inside the corrugated horn in terms of the eigenmodes corresponding to the different waveguide sections comprising the corrugation. The external (radiation) field on the other hand is expressed as a multiple-multipole expansion. The continuity of the electromagnetic field at both the aperture and the metallic boundaries of the horn are enforced using a point matching procedure. A computer code based on the above described method is integrated into an optimization algorithm giving rise to a complete software for the analysis and optimization of this type of primary radiators.