Consider the following statements regarding feed which is the Key component of a reflector antenna as it has a decisive bearing on the overall-performance:
1. For a horn-feed antenna the reflector focus must coincide with horn-feeds phase centre, which for a wide-flare horn lies in the plane of horn aperture.
2. The feed must have minimal radiation outside the angular aperture of reflector.
3. In print focus or cassegrain systems, the main or sub-reflectors should be in Fraunhofer zone of the feed antenna.
Which of the statements are correct?