Spectral estimation of noise in radar apparatus

A circuit arrangement, comprising:

• a first radio frequency (RF) oscillator configured to generate a first RF signal;
• a second RF oscillator configured to generate a second RF signal;
• a mixer configured to receive the first RF signal and the second RF signal as input signals and generate a mixer output signal based thereon;
• an analog-to-digital converter, connected downstream of the mixer, configured to digitize the mixer output signal provided by the mixer to generate a digitized mixer output signal;
• and
• a computation unit, including at least one processor, configured to:
• receive the digitized mixer output signal and to calculate an estimate of a power spectral density of the mixer output signal based on the digitized mixer output signal, and
• calculate an estimate for a noise power spectral density based on the estimate of the power spectral density of the mixer output signal, the estimate for the noise power spectral density characterizing noise contained in the first RF signal and noise contained in the second RF signal.