Extracting RLCG values from S-parameter data

[elmo jenkins]

rlcg to s parameter

Hello designers,

I am trying to design a lossy transmission line but I am having trouble obtaining RLCG values from s-parameter data from a 2-port network I am using. My frequency range is 0.02 GHz to 4.05GHz, is there any one who has RLCG values for this range; Or can help me extract this values from s-parameter data.

 

[sergio mariotti]

I'm not sure if the r,l,c,g, parameters are computable from 2port spar.
Of course you can extract Zo and loss.
Zo=√L/C , but an infinitely large pair of value satisfy this ratio
Also the Loss contribution is the sum of two contribution, namely dissipative loss on the conductor (related to R) and the polar dissipation on the dielectric (related to G) but once again an infinitely large ombination of this two value give the same loss.
But to find G and R you may do more.
If conductor is a non-magnetic metal and dielectric has constant εr vs. freq. and no DC hysteresys, there is a model (not a phisycal law!) that say the metal loss (in dB) is proportional to √Freq and the loss of dielectric is proportional to freq.

So from 2 port spar find:
1) group delay ... electrical lenght
2) The center of the rotational circle of s11 on Smith Chart ... it's Zo
3) The Available Gain vs freq, then find the contribute proportional to √Freq and the contribute proportional to Freq and normalize for unit lenght.

I'm not able to help you more.