Hello everyone, I use the noise option '029' to make noise power measurements for a measurement chain composed of an LNA and an impedance tuner just at the input of the LNA. I am trying to determine the output noise power (from the chain only) for each tuner position. Basically i have two questions to ask

1- What is the appropriate parameter that allows to do this measurement because there are two parameters that are "DUTNPDI and DUTNPD" knowing that my noise calibration is done at the end of cable of port 2 with a noise source and also at the level of reference plan of DUT?

2- can I say that these two parameters are the total noise power available at the output and which is the power of noise available at the output due to the sources (KTB Ga) + the internal noise power of the chain ?

Ga: available gain of the measurement chain

T: ambient temperature

K : Boltzmann constant

B: bandwidth (1Hz)

Thank you so much

Cordially

1- What is the appropriate parameter that allows to do this measurement because there are two parameters that are "DUTNPDI and DUTNPD" knowing that my noise calibration is done at the end of cable of port 2 with a noise source and also at the level of reference plan of DUT?There are two noise power measures: Available noise power density (DUTNPD, power to a conjugately matched load) and Incident Noise power (DUTNPDI, power delivered to the a non-radiating non reflective load, e.g. 50 ohm). Normally you want to use DUTRNPI. But in some cases you might want available noise power, for example, to get the equivalent temperature of the noise. A resistor at a temperature T, will have available noise power of kTB, but will deliver Incident noise power to a 50 ohm load of the value kTB*(1-|GammaLoad|l^2). For a 50 ohm resistor, gamma=0 and DUTNPDI=DUTNPD. We measure S22 of the DUT to determine gamma of the load to make the computation (and for some other stuff too).

2- can I say that these two parameters are the total noise power available at the output and which is the power of noise available at the output due to the sources (KTB Ga) + the internal noise power of the chain ?Sorry, I'm a little confused by the question.

(only DUTNPD is available, DUTNPDI is incident from the DUT). They both measure the total noise power received by receiver, including kTB*G plus and added noise. They exclude the noise generated in the PNA receiver (that's the difference between DUT and SYSNPD). There is no distinction from the input generated noise, as it is a total noise power measurement.can I say that these two parameters are the total noise power availableIn noise figure, we do account for the incident noise caused by the input termination, and this portion of the noise (times the gain) is in-essence subtracted from the total noise to determine the Te of the DUT. But only done as a NF measurement and not as a Noise Power measurement.