This is a calculator to determine Noise Figure of a device using the Y-Factor method.
Test setup:
For accurate measurements, you need to know what the Net Noise Figure is from the output of your DUT to the input of your Spectrum Analyzer (LNA plus all RF cabling). Call this NFLNA.
Analysis:The Net Noise Power (linear) of the entire chain is:
where Y (dB) = |Phot - Pcold| (dBm), and ENR (dB) is listed in a table on your ENR source as a function of frequency. Phot and Pcold are the noise powers observed on the Spectrum Analyzer when the ENR source is turned ON then OFF.
By re-arranging the Noise Cascade equation, the Noise Power of the DUT, FDUT, is:
*Note: All components of this equation are linear, not dB.
In review, this is what you need to measure:
Test setup:
For accurate measurements, you need to know what the Net Noise Figure is from the output of your DUT to the input of your Spectrum Analyzer (LNA plus all RF cabling). Call this NFLNA.
Analysis:The Net Noise Power (linear) of the entire chain is:
where Y (dB) = |Phot - Pcold| (dBm), and ENR (dB) is listed in a table on your ENR source as a function of frequency. Phot and Pcold are the noise powers observed on the Spectrum Analyzer when the ENR source is turned ON then OFF.
By re-arranging the Noise Cascade equation, the Noise Power of the DUT, FDUT, is:
FDUT = Fnet - (FLNA-1)/GDUT
*Note: All components of this equation are linear, not dB.
In review, this is what you need to measure:
Why linear and not dBm?
ReplyDelete