Design of subreflectors to compensate for cassegrain main reflector deformations

There can be economic and technical advantage in compensating for measured errors in the main reflector of a Cassegrain antenna by refiguring the subreflector. A design procedure (realised as a software package) is described whereby, given a set of measured main reflector errors, ordinates defining a comprehensively checked redesign for the subreflector are provided. Efficient ray tracing and interpolation algorithms are included in the software package, which is illustrated with numerical results indicating the improvements in antenna performance to be expected when a Cassegrain subreflector is redesigned.