A Model for RF Coupling on Spacecraft Antennas

Satellites antenna farms are becoming very critical in terms of antenna accommodation requirements, due to the high level of integration of the satellite and due to multi band operations required from customer missions. The optimal payload performances drive an early design of RF filters and antenna placement. Once the satellite integration goes in advanced phase, the antenna replacement becomes costly and impacts timing. Sometimes the decoupling level requested between two antennas is challenging and has to be predicted and verified by very accurate and reliable modeling tools [3]–[9] with the aim to minimize and optimize the testing at satellite level due to accessibility issues and to schedule constraints. Scope of this paper is to show an effective approach to predict antenna coupling factors applying EM simulation tools on a real industrial case where a possible EMI risk between a very large SAR array and Data Downlink antenna in X-band was studied. The GALILEO-EMT [1] suite was applied in this activity that ended with a coupling test on a representative satellite Mockup designed by Thales Alenia Space Italia team in the frame of a Low Orbit Earth Observation Satellite qualification (i.e. COSMO-SkyMed, a program managed by the Italian Space Agency (ASI) and co-funded by ASI and the Italian Minister of Defence).