Aperture-field uniformity and cross-polarization level of dual parabolic cylindrical reflectors

Abstract

For dual parabolic cylindrical reflectors, the field distribution over the aperture is calculated. This aperture-field distribution is a function of the feed orientation, and feed radiation pattern, the feed polarization, and the geometry of the configuration, in particular, the focal lengths of the two reflectors and the angle between them. The effects of these parameters on the uniformity of the co-polar component and the level of the cross-polar component of the aperture field are studied, and some representative results are presented. It is shown that by a proper selection of the geometrical parameters of the system, a high degree of co-polar field uniformity on the aperture can be maintained. Therefore, the system can be used as a compact antenna range to test large antennas.