A dielectric hybrid mode antenna feed: A simple alternative to the corrugated horn

A hybrid-mode horn antenna has been analyzed theoretically and experimentally. It consists of a conical metal horn with a dielectric core inside, separated from the metal wall by another dielectric layer with lower permittivity than for the core material. It is characterized by a very simple design and excellent electrical performance. The horn can support the balanced hybrid HE11-mode, and exhibits low cross polarization and low sidelobes over a wide frequency range. Compared to corrugated horns, the new horn has a simpler design, is easier to analyze, and has the potential of similar cross-polar bandwidth as for corrugated horns with ring-loaded corrugations. Drawbacks are the effects of dielectric losses. Thus the new horn represents an attractive alternative to the corrugated horn antenna.