An apparatus for monitoring radio frequency (RF) signals is disclosed. The apparatus includes an RF splitter, a set of track-and-hold circuits, a set of analog-to-digital circuits (ADC) and a frequency tracking module. The RF splitter splits a set of incoming RF signals into multiple RF signal paths. Each of the track-and-hold circuits, which is clocked at a different frequency than others, samples the incoming RF signals from a respective one of the RF signal paths. Each of the ADCs receives the sampled data from a respective one of the track-and-hold circuits. Each of the ADCs is also clocked at same frequency as a corresponding one of the track-and-hold circuits. The frequency tracking module determines a frequency of the incoming RF signals.