Aperture arrays for the Square Kilometre Array

The radio astronomy community is entering a new era with the design and planned construction of the Square Kilometre Array (SKA). The SKA will have 10-100 times improved sensitivity and 10⁵ survey speed compared to existing radio telescopes. Besides a large number of dishes, Aperture Arrays (AA) are being considered, promising the potential of a very large Field of View (FoV): the FoV for AA´s is in theory only limited by the computing power. Aperture arrays are therefore the preferred solution for low frequency astronomy, where a distinction is made between AA-low, specified to run from 70 to 450MHz, and AA-mid, specified for 400-1420MHz.