Ultra Gaussian Corrugated Horns
Recent developments made by Graham Smith in St. Andrews, connected with the need for very low standing waves in QO systems have lead to the development of what we call Ultra-Gaussian Corrugated horns, producing very low sidelobe axially symmetric beams.
A CORRUG design for a 5 GHz (low frequency for us) Ultra-Gaussian Horn for Cosmic Microwave Background workMore details can be found here