how to extract lumped model from coupled line s parmeters?

how to extract lumped model from coupled line s parmeters? I have simulated two lines in vicinity and have 4 port s parametrs?thanks.

What kind of model are you looking for?
Is the line short compared to the wavelength, so that a simple pi model works?

Some circuit simulators like PSpice or Spectre also offer a coupled line model which takes R'C'L'G' values.

Yes the lines are short with respect to wavelength.

I want to know, through equations how can I extract R,L,G, C and coupling coeffcient, k, from s -parameters so that I can build a lumped model?

Here is a paper which describes the pi model extraction:

J. C. Rautio, "Synthesis of Lumped Models from N-Port Scattering Parameter Data," IEEE Tran. Microwave Theory Tech., Vol. 42, No. 3, March 1994, pp. 535-537

PDF Download:
http://www.sonnetsoftware.com/suppor...TransMar94.pdf

The algorithm is built into the free student version of the Sonnet simulator, called Sonnet Lite. You can load your *.snp files into the response viewer and export the pi model from there.

Thanks for the paper. Interestingly, this paper leaves out how to calculate mutual coupling which is what I want. I want to hand calculate it to learn. Please let me know if you have come across such routine in book or paper? thanks.

Hello again,

unfortunately, I do not have additional references. The mutual coupling k between inductors is implemented in the software, but I have no other description about the underlying equations.