A non-transitory computer-readable storage device stores machine instructions which, when executed by a processor, cause the processor to determine a chirp period Tc for radar chirps in a radar frame. The chirp period Tc comprises a rising period Trise and a falling period Tfall. The processor determines, for each radar chirp in the radar frame, a corresponding randomized frequency characteristic during Tfall, and causes a radar sensor circuit to generate the radar chirps in the radar frame based on Tc, Trise, Tfall, and the corresponding randomized frequency characteristics. In some implementations, the machine instructions to determine the corresponding randomized frequency characteristic comprise machine instructions to determine a frequency step having a frequency f_step and a period Tstep. At least one of the frequency f_step and the period Tstep is dithered across radar chirps in the radar frame.