How to get ideal capacitor s-parameters to produce similar results to the built in capacitor element in Serial Link Designer in MATLAB R2022a and beyond?

I have created a new project in Serial Link Designer and swapped out the auto-generated diff-pair element with capacitor s-parameter elements. These capacitor s-parameters represent an ideal capacitor. Why does the generated statistical eye diagram show significantly more degradation than when running the model with the built in capacitor elements from the SI toolbox? How can I get the model with s-parameter ideal capacitors to show similar results to the model with SI toolbox capacitors?

Built-in Capacitor Results:

 

S-Parameter Ideal Capacitor Results (would expect to be very similar to the statistical eye diagram above):

Answer 1

[MathWorks Support Team]

To resolve this issue, try one or both of the following when creating S-Parameters (even for non-ideal capacitors):

1. Remove the 0Hz point from the ideal capacitor S-Parameter file. If there is a discontinuity between the 0Hz point and the higher frequencies of the S-Parameter file this could be what is causing the excessive degradation seen in the statistical eye diagram.
2. When creating S-parameters, include the equivalent series resistance (ESR), equivalent series inductance and other parasitics to create more realistic low frequency behavior that the network solver can handle better.