Hello Sweetchoto, thanks a lot for your help. I had a (quick) look on your pdf and it helps but honestly I don't have the answer of my question. To make sure I asked properly my question, look at **broken link removed** on page 41. There is an asymmetry which is taken to make "the Direct-Transmission Method" (driven mode) according to what I understand.
I guess that Driven mode and "the Direct-Transmission Method" is the same thing because you extract the dispersion diagram (with a formula) from S parameters, right ? Actually I want to use this technique because 2D dispersion diagram takes too much time.
Do you have an idea ? Thanks !!