On divided-fitting method of large distorted reflector antennas based Coons surface

Best-fit paraboloid is usually adopted to analyze distorted reflector antennas, which, however, may make the big partial distortion of antenna reflector unnoticeable. Based on the shape of distorted reflector, a new divided-fitting approach is presented combining the hoop trigonometric function fitting and quadratic radial function fitting methods, and adopting Coons surface to fit each divided zone. By this way the reflector can be analyzed and fitted accurately. The derivation of required formulae to calculate the surface deviation is also submitted. The application of the divided-fitting method to analyze a 7.3-m large reflector antenna and the computation of its electrical performances are given in detail with right and useful results.