A self-checking predictor-corrector algorithm for efficientevaluation of reflector antenna radiation integrals

An efficient algorithm for numerically evaluating diffraction integrals is presented. The algorithm employs a predictor-corrector scheme combined with Ludwig's (1968) integration procedure. The predictor-corrector eliminates the amplitude and phase ambiguities present in the real+imaginary algebra used in machine calculations and provides accuracy self-checking capabilities. The end result is a reliable and efficient integration method that does not require independent integrand phase information, can handle arbitrarily shaped integration domains, and is capable of monitoring its own accuracy as the integration proceeds. The performance of the algorithm is investigated by computing, using the physical optics technique, the electromagnetic field scattered by representative reflector antenna geometries. These tests demonstrate that the proposed algorithm is particularly efficient in the analysis of multi-reflector systems