Simulate odd mode/even mode impedance using 4 port S/Z/ABCD parameters

[vlsi_design2]

Hi, I am designing a coupled line coupler and I want to simulate Zoe and Zoo vs freq. How can I express using S or Z or ABCD parameters?

 

[vlsi_design2]

Can I use an ideal balun and reduce it to a two port problem and do s param -> ABCD pram and the use sqrt(B/C) to find Zoo. Can I use center tap of the balun to evaluate Zoe?

 

[ferdem]

Can I use an ideal balun and reduce it to a two port problem and do s param -> ABCD pram and the use sqrt(B/C) to find Zoo. Can I use center tap of the balun to evaluate Zoe?

It looks correct to me. If you excite the line differentially (two lines excited at 180 degree out of phase), the impedance you observe will be the odd mode impedance. Similarly, if you excite the lines in even mode (two lines excited with the same phase with respect to a third node called common node), that is, you apply the same sinusoid to the both lines, you will observe the even mode impedance.
From ABCD parameters, you can calculate the impedance as you stated.