An apparatus, including processing unit (PU) cores and computer readable storage devices storing machine instructions for determining a distance between a target object and a radar sensor circuit. The PU cores receive a beat signal generated by the radar sensor circuit and compensate for a phase difference between the received beat signal and a reconstruction of the received beat signal to obtain a phase compensated beat signal. The phase compensated beat signal is then filtered to remove spurious reflections by demodulating the phase compensated beat signal using an estimated frequency of the phase compensated beat signal. The PU cores then apply a low pass filter to the demodulated phase compensated beat signal, resulting in a modified beat signal. The PU cores then determine the distance between the target object and the radar sensor circuit using the modified beat signal.