Reconfigurable RF circuits are expected to become essential microwave components of next-generation wireless-communications and radar systems. In this paper, the usefulness of a tunable notch filter for interference mitigation is evaluated. In particular, the effects of an unintentional interference tone on the imaging performance of a coherent frequency-modulated-continuous-wave (FMCW) radar are assessed through simulation. The reported study serves to theoretically justify the operational benefits from the integration of reconfigurable notch filters into modern RF front-ends of coherent FMCW short-range radars. A specific experimental setup is also suggested for the practical verification of this analysis in a laboratory environment.