Noise figure measurement in radar systems

A radar system comprising:

• a test signal generator configured to generate, as a test signal, a random signal modulated onto an RF signal, wherein a power of the random signal is configurable,
• a radar receiver channel including:
• an RF frontend that is configured to receive the test signal and to down-convert the test signal into a baseband to provide a baseband signal, and
• a baseband signal processing circuit configured to receive the baseband signal and to attenuate, by an attenuator circuit, the baseband signal with a configurable attenuation;
• a digital-to-analog converter configured to digitize an output signal of the baseband signal processing circuit;
• a system controller configured to control an operation of the test signal generator and to control the attenuator circuit to set the power of the random signal and the configurable attenuation of the attenuator circuit;
• and
• a processing circuit configured to:
• process the digitized output signal of the baseband signal processing circuit;
• determine a noise parameter of an output signal of the baseband signal processing circuit to obtain a first noise value, the noise parameter being determined to obtain the first noise value while the power of the random signal is set to a first power value and the configurable attenuation is set to a first attenuation value;
• determine the noise parameter of the output signal to obtain a second noise value, the noise parameter being determined to obtain the second noise value while the power of the random signal is set to a second power value and the configurable attenuation is set to the first attenuation value;
• determine the noise parameter of the output signal to obtain a third noise value, the noise parameter being determined to obtain the third noise value while the power of the random signal is set to the first power value and the configurable attenuation is set to a second attenuation value;
• determine the noise parameter of the output signal to obtain a fourth noise value, the noise parameter being determined to obtain the fourth noise value while the power of the random signal is set to the second power value and the configurable attenuation is set to the second attenuation value;
• and
• determine a value representing a noise figure of the radar receiver channel based on the first noise value, the second noise value, the third noise value, and the fourth noise value.