Diffraction synthesis of dual-reflector antennas considering array feed, blockage, and near-field effect

A diffraction synthesis technique for reflector shaping based on orthogonal global surface expansion and optimization techniques was presented by Y. Rahmat-Samii and J. Mumford (1989). The key step is to parameterize the antenna system under investigation, and determine the optimum values of these parameters using an optimization algorithm. A diffraction analysis computer program is used to compute the radiated fields in the course of optimizing an object (cost) function defined by the computed and the desired field quantities. An important feature of this optimization approach is that no more approximations than those assumed in the analysis are required. This implies that, in contrast to the geometrical optics (GO) synthesis methods, diffraction phenomena, near-field effect, and blockage effect can be taken into account automatically. In the present work, typical results on the application of this versatile diffraction synthesis technique to dual-reflector antennas fed by a single point source or array horn feeds are presented.<>