SNR Considerations for RF Sampling Receivers for Phased Array Radars

This paper considers the implementation of a digital receiver suitable for a Transmit/Receive (T/R) module in phased array radars. In particular, the achievable SNR performance of an L-band RF sub-sampling receiver will be investigated as a function of the Analogue to Digital Converter (ADC) sample rate. The SNR is measured per unit bandwidth, as it is assumed that the ADC is followed by a digital filter which limits the spectrum to the desired signal bandwidth. The SNR performance of a direct RF sub-sampling receiver is also compared against a single-conversion receiver using a mixer stage prior to ADC conversion.