LNA mixed-signal mode Noise Figure de-embeding

[fred3991]

Hi everyone,

I was wondering if it is possible to get NF from Single-ended to differential LNA measurements using Friis formula?

The complete measurement setup looks like this

I need to determine the NF for the LNA.


I have checked this solution using matlab.
(lets Assume that the NF for this LNA is 4 dB***)

Result in matlab

Is this approach acceptable and correct, or should other deembedding techniques be used to determine NF for LNA?


Thanks in advance for any information and ideas provided.

 

[BigBoss]

It's principally correct. Either single ended or differential, the Friis Equation is always identical.
I didn't check Matlab script, no idea.

 

[fred3991]

It's principally correct. Either single ended or differential, the Friis Equation is always identical.
I didn't check Matlab script, no idea.

In matlab I just symbolically solved the NF of stage 2 (LNA) from Friis, and then solved this equation and got again the value of NF =4 dB