The quadruple-ridged flared horn: A flexible, multi-octave reflector feed spanning f/0,3 to f/2.5

In this paper, we present four quadruple-ridged flared horn designs achieving 6-1 frequency bandwidth with good match and near-constant beamwidth in E- and D-planes. Nominal 10 dB beamwidths of the designs range from 32 to 115 degrees. Such design flexibility makes the quad-ridge horn a very attractive reflector antenna feed candidate, especially for next generation radio telescopes.