Prediction of Far-Field Pattern Characteristics of Phased Array Fed Reflector Antennas by Modeling Only a Small Part of the Array — Case Study of Spaceborne Radiometer Antennas

In this work we present an approach for the prediction of far-field pattern characteristics of phased array fed reflector antennas by modeling only a small part of the array. In this approach, the simulated EEPs of the FPA are modeled as the phase-shifted versions of the simulated embedded element pattern (EEP) of the central element, and thereafter combined with the optimum weighting coefficients in order to find the total pattern of the feed. Although, the EEPs of dense array antennas are generally not identical (due to the array antenna mutual coupling and edge truncation effects), for typical FPA excitation scenarios, where the array edge elements have relatively low weights to produce the desired illumination of the reflector, this simplified approach has been found sufficiently accurate.