ASKAP Beamformer

The SKA will be the mainstay of centimeter astronomy much of this century. It will have a sensitivity that is more than an order of magnitude greater than current radio telescopes. A second area for improved performance is the field of view (FoV). For frequencies above 1GHz a greater FoV may be achieved by placing a Phased Array Feed (PAF) at the focus of each of the SKA dishes. The design of the signal processing chain to convert the signal from a PAF to multiple independent beams on the sky is a major challenge. This paper describes the approach used by the Australian SKA Pathfinder (ASKAP) to achieve this. The approach leads to a telescope that has a 30 square degree field of view at 1.45GHz.