Curved-aperture Corrugated Conical Horn
Image of the Curved-aperture Corrugated Conical Horn.

The smooth wall conical horn antenna is popular in the microwave band, where it is commonly used as a feed for communication or satellite dishes and radio telescopes. Its mechanical body of revolution symmetry supports any polarisation of the excited fundamental (TE11) mode - including circular (excited by using two orthogonal coaxial to waveguide transducers driven in phase quadrature).

While normal smooth-wall horns present problems that can be eliminated by corrugating the walls, the performance of simple linear corrugated horns may be improved through a number of techniques - one of which involves profiling the flare. Such a profiled flare has a number of advantages - most importantly the reduction of cross-polarisation.

Typical applications for the antenna include frequency reuse applications in satellite and terrestrial communications, where the cross-polar sidelobe level of -30dB or better over the band is required. When properly designed, curved aperture profiled horns can achieve a cross-polar sidelobe intensity below -50dB at the centre of the operating band.

The implementation of the design in Antenna Magus allows the degree of sidelobe reductions to be selected as ‘Low’, ‘Average’, ‘Good’ or ‘Best’ along with frequency. This selection impacts on the profile and corrugation design allowing for a trade-off between performance and complexity/size of the structure. Further refinement of the profile and corrugations can be completed using the parametric export model if needed.

Curved conical corrugated horn antenna with 3D gain pattern at the centre frequency
Gain comparison at centre frequency for all design cases