Propagation and radiation behaviour of dual-depth corrugated horns

A study of the propagation and radiation behavior of dual-depth corrugated horns is reported. These horns have radiation characteristics with pattern symmetry and low crosspolarisation in two separate frequency bands. They are analysed using a space-harmonic formulation, which enables a parametric study of the influence of the geometry of the horn on the crosspolar characteristics to be undertaken. The dual-depth horn is predicted to operate over a ratio of frequency bands between 1.3 and 2.0. The number of slots per wavelength should be about seven in the high-frequency band, in which case a performance similar to a single-depth corrugated horn is expected.