Noise Factor Measurement on 50 Ω

This chapter discusses the procedure for performing noise factor measurements for a source impedance Z
_S
= R
₀
= 50 ohm. The source impedance value is not a choice, but it is the only possible value if a tuner is unavailable to vary the value of the source impedance. A Keysight N9320A spectrum analyzer with the built‐in amplifier option is used to measure noise power. When making a noise factor measurement for a given source impedance with a noise diode, it is necessary to measure two noise powers N
_C
and N
_H
which respectively correspond to the noise power measured at the output of the device under test, With regard to the value of the noise factor of the adapted attenuator, it is possible to compare measurements of parameters S made to the network analyzer.