Broad-band flared horn with low sidelobes

A circular horn antenna flared like a trumpet has been analyzed with the geometrical theory of diffraction and tested experimentally. Sidelobes are extremely low (-75 dB) and agree with theory. Low sidelobe performance is predicted to be broad-band and to improve with higher frequencies. The full aperture of the tested horn is about
50 \lambda
. Suggestions are made for even better low sidelobe antennas.