ANALYSIS AND DESIGN OF RADIAL RIB REFLECTOR ANTENNAS

The radiation characteristics of radial rib reflector antennas are studied. This type of antenna can be used as a large deployable satellite antenna. The radiation patterns of a axi-symmetric reflector are computed using both an exact physical optics analysis and a simplified approximate analysis in order to understand the behaviour of the rib-related sidelobes which have a cyclic behaviour in the azimuthal direction. A parametric study is conducted. A shaped sub-reflector is designed using diffraction profile synthesis to compensate for some of the errors introduced by the main radial rib reflector.