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Deembedding and reflection coefficient - RF Cafe Forums

Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views. It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if you would like to post something on RF Cafe's Facebook page, please do.

Below are all of the forum threads, including all the responses to the original posts.


RF-Ban
Post subject: Deembedding and reflection coefficient Posted: Wed Jan 11, 2006 10:51 am

Captain

Joined: Sat Feb 26, 2005 5:24 pm
Posts: 16
Location: Lille, FRANCE
Hello,
I am trying to deembed measurements from TDR and i don't see why i can't get the results i want.
I explain my problem:
I have measured through a VNA the reflection coefficients of 3 standards (S0L), and 3 other components. I made a TDR measurement of those components and standards.
From the TDR of the standardsi apply a fft and thanks to the current and voltage i get the measured reflection coefficient of each:
a=(V+ZI)/sqrt(Real(Z));
b=(V-ZI)/sqrt(Real(Z));
S11m=b/a;
Knowing their true reflection coefficients thanks to the VNA, i compute the error vectors:
b=e11;
c=e22;
a=e21-e11*e22;

The problem is that when i use those vectors with TDR of the standards i find back the good s-parameters of the standards, but when i do this with other components i don't find at all.
with :
S11a=(S11m-b)/(a+c.*S11m);

Note : the time span and step, and frequency span and step permits to work one with each other.
Can someone help me ? Thank you




Posted  11/12/2012
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