SKA Aperture Array Digital Beamforming Technique

The Square Kilometre Array (SKA) [1] telescope will be built in two phases: initially the SKA1 will include a large low frequency phased array operating from 50MHz to 350MHz (SKA1-Low) and the Full SKA will have a larger low frequency array and is anticipated to deploy a mid-frequency phased array, AA-mid, operating up to ∼1.5GHz. The SKA1-Low array will have 131,072 antennas arranged as 512 stations of 256 antennas with a flexibly allocated bandwidth of 300MHz; this is anticipated to be extended to > 1 million antennas with a greater capability in numbers of beams and total usable bandwidth in the Full SKA. The AA-mid is even more ambitious with a possible “all-digital” implementation of up to 8 million antennas likely to be arranged in 1024 stations. The total processing required for AA-mid will be very high with ∼ 1GHz bandwidth and hundreds of independent beams.