Design of profiled corrugated horns

The design principles used to realize smoothly profiled corrugated horns are described. The smooth profiling causes power to be converted to higher order HE/sub 12/ modes which radiate to produce high sidelobes in the copolarization patterns. A computer-aided spherical modal-matching technique is used to study the higher-order mode conversion. The results show good agreement with measurements. A profiled horn using a series of discrete conical sections is proposed to eliminate most of the mode conversion. A horn designed in this way is presented and shown to possess improved performance characteristics in comparison to a smoothly profiled design.>