Beam diffraction by parabolic reflector

It is noted that wide-angle radiation patterns of a parabolic reflector can now be efficiently calculated with the uniform geometrical theory of diffraction. In this approach edge diffracted fields are conveniently assumed those of an isotropic source at the focus with amplitude equal to feed radiation in the edge directions. While accurate for diffraction in the forward and rear directions, this assumption can be less accurate for lateral radiation and spillover lobes of the pattern. With the complex source point method the approximation of an isotropic source is no longer necessary. Beam diffraction by the edge can now be predicted simply and accurately. This is demonstrated for two-dimensional beam diffraction by a parabolic cylinder reflector.<>