computational em
Hi, Smithchart:
There are many ways. I documented a few ways in my Ph.D. thesis (Jian-Xiong Zheng, Dept. of ECE, Univ of Coloardo at Boulder, 1990). Some of them are from other users and some of them came up to me. One simple way I came up was the 3-point method:
You solve the current at 3 uniformly spaced points Ja, Jb, Jc. The current should be free of higher order modes.
J = a * exp ( - gamma * z ) - b * exp( gamma * z )
If you calculate (Ja+Jc) / Jb, you will be able to find gamma. From gamma, you can find a, and b.
This will allow you to find the relative incident and reflected wave on one port at an excitation state. Using some linear algebra, you will be able to find the s-parameters of a general N-port structure. The detail is in my thesis. Interestingly, I even do not keep a copy of it.
Best regards,