Analysis of the ADC resolution for radio astronomy applications

This paper discusses the optimization procedure and the selection of the resolution of the analog/digital converter (ADC) for the Square Kilometre Array (SKA) receiver chain. Once the optimum input voltage levels of ADCs with different resolutions are selected, the maximum interference levels and correlator integration time are investigated for a two-antenna system. The selection methodology, based on comparison with an ideal ADC, is outlined using the SKA as an example. This selection methodology can also be applied to other receivers with a different criteria. This work determines that the minimum required number of bits for an SKA ADC is 4 bits provided that the input signal level to the ADC is set properly.