A hybrid PO/NF-FF method to estimate the blockage effects on the performance of spacecraft mounted reflector antennas

This paper addresses a hybrid PO/NF-FF method using near-field to far-field transformation combined with -fill hypothesis to estimate the effect of blockage on the far-field pattern and beam efficiency of reflector antennas. The main advantage of this method is that it can be potentially used for any arbitrary shape of blockage or side components. To estimate the blocking effect on the beam efficiency, a new definition of beam efficiency is introduced based on the total forward radiated power in the near-field measurement plane. A new parameter, "power ratio", is also defined for the cases where the blocking effect of deployed components can not be observed easily. Lastly, the results are shown for a case study in which the effect of some side panels is estimated on the reflector performance.