Efficiency of arrays composed of high-gain reflector antennas

Arrays composed of high-gain reflector antennas are used for radio-astronomical purposes and, more recently, are proposed as ground station for deep space communications. This latter application requires a precise knowledge of the degradation that phase, amplitude and pointing fluctuations impose on the capability of the array to combine coherently the signal received or transmitted from each antenna. In this study, an analytical model for the fluctuation of each parameter (phase, amplitude and pointing) is derived and it is used to predict the efficiency of an array composed of an arbitrary number of high-gain reflector antennas. The analytical models are verified by numerical simulations and applied to an array layout currently proposed as possible future ground stations for the European Space Agency.