System design for SKA capable aperture arrays

Aperture Arrays are a major collector technology for the Square Kilometre Array, SKA, covering both the low, 70-450MHz, and mid-frequencies, 400-1450MHz. They provide the very high survey speed performance and ability to have extremely large collector areas at the low frequencies. Aperture arrays consist of a large number, up to millions, of small, fixed receiving elements arranged into logical stations, providing many independent beams on the sky. The station design to deliver SKA performance is a processing and communications challenge and rely on the technology advances predicted by the ICT industry. This paper considers the system design for a low frequency array, to be deployed in SKA Phase 1, its extension to the full SKA and the implementation of the very challenging mid-frequency array for deployment in the full SKA in the early 2020´s.