One example of a radar device includes a phase-locked loop for generating a radiofrequency signal. The phase-locked loop has a multi-modulus divider. The radar device furthermore comprises a delta-sigma modulator for generating a modulated signal for the multi-modulus divider, and a signal generator for generating an input signal for the delta-sigma modulator. The radar device has monitoring circuits, wherein a first monitoring circuit is configured to monitor a locked state of the phase-locked loop, a second monitoring circuit is configured to monitor the delta-sigma modulator, and a third monitoring circuit is configured to monitor the signal generator.