Investigation of reflector-antenna radiation

The derivation and programming of mathematical models for both offset and symmetrical parabolic reflectors with either linear or circularly-polarized primary feeds is described. Feed location is constrained to the general vicinity of the geometric focus, and, in the case of the symmetrical (paraboloidal) reflectors, aperture blocking effects are modelled by the shadow-diffraction technique. Theoretical models were applied to study the radiation from a typical one meter diameter paraboloidal reflector-antenna operating at 12 GHz. Sources of cross-polarized radiation were identified.