Improving the Strut Modelling of the European Space Agency Deep Space Antennas to Evaluate Efficiency and Sidelobe Impact

Large reflector antennas necessitate the presence of struts to support, according to the configuration, feeds or sub-reflectors. This paper presents the results of an investigation, in terms of sidelobe level and efficiency, of the impact on the antenna performance of the struts, considering the upcoming European Deep Space Antenna 4 (DSA4). In particular, for the first time in the framework of the DSA4 project, the strut model includes a tapering of the diameter of the strut itself, and a service platform and ladder (needed to reach the sub-reflector for maintenance), thus modeling with greater accuracy the real situation. The simulations presented here, carried out using Physical Optics, represent a rare opportunity to investigate these aspects, most often discarded due to the large computational time, and show that the impact on the antenna performance, for such high-end antennas, may be not negligible.