Analysis of reflector antenna systems with arbitrary feed arrays using primary field superposition

In contrast to secondary pattern superposition, where the fields reflected from the main reflector arising from each element are superimposed in the far field of the reflector, the approach presented here sums the primary fields at the reflector surface before the physical optics radiation integral is performed. The method allows each feed array element to have arbitrary position, orientation, pattern, and excitation (magnitude and phase). In addition, it is inherently efficient because evaluation of only one time-consuming radiation integral is required, rather than one per feed element as in secondary superposition. The method allows for accurate calculation of the power radiated from the feed, permitting the reflector gain and spillover efficiency to be determined within the context of a single computer program. The accuracies and characteristics of this method are demonstrated with several examples