Liu, LeiLeiLiuGrainge, KeithKeithGraingeNavarrini, AlessandroAlessandroNavarrini2020-09-232020-09-232017978-1-5090-4837-3http://hdl.handle.net/20.500.12386/27467This paper focus on the analysis of S parameter and beam pattern of an array of Vivaldi antennas used by a cryogenically cooled phased array feeds for radio astronomy application. The low-noise cryogenic front-end operates across the 4 – 8 GHz band and can simultaneously form four independent beams. Signals from the dual-polarized Vivaldi antenna array are combined by an analog beamformer located inside the cryostat. The vacuum window consists of a dome-shaped structure made of Plexiglas. We report on the results of the investigation of mutual coupling between the antenna elements and how the dome affects S parameter and beam pattern.ELETTRONICOenConference paper10.1109/NEMO.2017.79642442-s2.0-85028502730https://ieeexplore.ieee.org/document/7964244FIS/05 - ASTRONOMIA E ASTROFISICA