Numerical Results for the System Noise Temperature of an Aperture Array   Tile and Comparison with Measurements
  The purpose of this report is to document the noise performance of a complex beamforming array antenna system and to characterize the recently developed noise measurement facility called THACO, which was developed at ASTRON. The receiver system includes the array antenna of strongly coupled 144 TSA elements, 144 Low Noise Amplifiers (LNAs) (Tmin =35-40K) and the data recording/storing facilities of the initial test station that allow for off-line digital beamforming. The primary goal of this study is to compare the measured receiver noise temperatures with the simulated values for several practical beamformers, and to predict the associated receiver noise coupling contribution, antenna thermal noise and ground noise pick-up (due to the back radiation). 
M.V. Ivashina, E.E.M. Woestenburg, L. Bakker, and R.H. Witvers
astro-ph.IM