The design of millimeter wave scanning reflector antennas

Designs for the main reflector and feed horn of a fixed feed scanning antenna system are studied. The shaping of the main reflector or a phase dielectric layer are used to correct the main reflector profile and maximize scanning performance. A comparision of the two reflectors reveals that the dielectric reflector has superior performance; however, it is heavier and costlier. The shape of the antenna feed horn maintains low sidelobe levels and symmetrical radiation patterns. The designs of Potter's (1963) dual-mode conical horn, Bailey's (1978) dual-mode conical horn, and a corrugated scalar horn are compared. The data reveal that the Potter horn has the lowest manufacturing cost, the Bailey horn has the most gain, and both conical horns have better radiation pattern symmetry than the scalar horn. Radome materials for the antenna subreflector support structure are evaluated.