How to analysis the coupled factor between twp parallel differential pairs?

There are two diff pairs, one transfers about 400M signal, and the other transfers 200MHz signal.
The two pairs are parallel, i.e. the four traces are parallel. The structure is coplanar.
I want to analysis the coupled factor in dB with AWR software, assume the trace width are all 60um, the separation in the diff line is 120 um. The separation between the two pairs' edge is 300um. The Cu height is 20um, and the upper Er=1, and the lower Er=4.3, the both heights are 60um. With Cu as the upper GND and as the down GND.
The question are as the following:
(1). should I must use EM structure?
(2). How to set the diff terminations?
(3). How to calculate the coupled factor in dB? That's something the same as the coupled factor in two parallel microstrip.
I am studying how to do EM simulation in AWR.
Hope you can help me, thanks.

You can consider your structure Directional Coupler therefore you should use EM simulation to find the coupling coefficients and directivity and return losses etc.
But I guess there isn't any diff. port definition and that's why you should use single ended ports and then simulate it ina schematic view.But in this case Zoo and Zee and their combinations won't be calculated.

Is there any way to use ADS or HFSS?
How to define diff ports in these software? And how to calculate the coupled factors?

tony_lth said:

(1). should I must use EM structure?

Click to expand...

Yes, this is a must, since your mutual coupling between circuits and lines can not be easily modeled by adjust your circuits anymore.

(2). How to set the diff terminations?

Click to expand...

You might find my posts at (https://www.edaboard.com/threads/263775/) useful, I think I asked exactly the same question.

(3). How to calculate the coupled factor in dB? That's something the same as the coupled factor in two parallel microstrip.

Click to expand...