Fast prediction of aperture efficiency and sidelobe levels in shaped reflector systems through model based output space mapping

This paper presents a fast method to accurately predict the aperture efficiency and sidelobe levels of shaped dual reflector systems over a wide region of the shaping parameter space. Only a few full evaluations of the system, at different points in the shaping parameter space, are needed to construct the model used for the predictions. The output space mapping technique is used to correct the responses obtained from a simple geometric optics model of the system for any desired point in the shaping parameter space by using the expected aperture edge taper information available from the shaping mapping and the feed pattern. The method is evaluated for a range of feeds, frequencies, and parameter spaces and shown to provide significantly improved results over the geometric optics predictions, while being orders of magnitude faster than full wave or asymptotic methods.