The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Measurements >> Other Measurements >> Niose Parameters not listed with S-Parameters ?
https://designers-guide.org/forum/YaBB.pl?num=1216991572

Message started by Stanley on Jul 25^th, 2008, 6:12am

Title: Niose Parameters not listed with S-Parameters ?
Post by Stanley on Jul 25^th, 2008, 6:12am

I have a question that I cannot find a good answer to; Why when you go the manufactures web site for a transistor or FET they give you the S2P file with the S-Parameters, but they do not include the noise parameters? (Fmin, Γopt, Rn, freq) Is their a way to get Γ[sub]opt and R[sub]n from knowing F[sub]min and the S-parameter for that frequency.
Every design book I have for LNA says that they give this information to you.

Title: Re: Niose Parameters not listed with S-Parameters ?
Post by pancho_hideboo on Jul 25^th, 2008, 6:55pm

Stanley wrote on Jul 25^th, 2008, 6:12am:

Why when you go the manufactures web site for a transistor or FET they give you the S2P file with the S-Parameters, but they do not include the noise parameters? (Fmin, Γopt, Rn, freq)

This is because noise parameters are not stable and need high cost in measurement compared to s-parameters.

Stanley wrote on Jul 25^th, 2008, 6:12am:

Is their a way to get Γ[sub]opt and R[sub]n from knowing F[sub]min and the S-parameter for that frequency.

You can't derive Γopt and Rn from Fmin and S-parameters.