An analysis of diffraction effects in a Cassegrain antenna with a mesh subreflector

A method is presented for analyzing two-reflector antennas with allowance for edge diffraction effects in a wire-mesh subreflector. The method involves solving numerically an integral equation describing the effect of diffraction at the edges of the subreflector as well as the effect of the subreflector curvature and the mesh size. It is shown that the use of a mesh in which the mesh size increases gradually toward the reflector edge makes it possible to substantially reduce the edge diffraction effects.