Noise Correction Spectrum (IQ-NC)
is the measured noise correction trace that will be applied when IQ Noise Correction is enabled and Analyzer Noise Correction Mode is selected.
This spectrum is displayed in dBm deciBels referenced to a milliWatt: dB relative to 1 milliwatt dissipated in the nominal input impedance of the analyzer/Hz and represents the noise present in the analyzer for the current setup (measurement span/center, RF Radio Frequency: A generic term for radio-based technologies, operating between the Low Frequency range (30k Hz) and the Extra High Frequency range (300 GHz). Path, Preselector, etc.). This noise includes only noise that is uncorrelated to the signal.
On some hardware, the noise spectrum can be measured using two different attenuations. If this is being done, the Noise Correction Raw Spectrum 1 and 2 traces will show the two different spectrum measurements. Along with the Noise Correction Spectrum trace, these can help the user determine if the noise spectrum is being measured correctly or if there might be some signal that is affecting the noise measurement. Other hardware may not need to use two attenuations and may be able to completely isolate the input from the signal. In this case, the two raw spectrum traces will be empty.
Some hardware may only be able to measure at a single attenuation and highly attenuate the input instead of terminate. You can view the Noise Correction Spectrum to check whether any signal appears present in the measured noise spectrum. If so, you may need to use a lower signal power.
If there is any problem measuring the noise correction spectrum, there will be a trace LED and a message if you click the LED.
Using Noise Correction will affect measurement speed. See IQ Noise Correction for more information.
See Also
