Difference b/t Microstrip Interdigital Capacitors

I would like to find out whether there are any differences between those simulation units.
#1

#2

Is there anyone who knows the difference between them?
From simulation results, they are almostly same.

I'd love to know the roles of MICAP3 and MICAP4.
I cannot see how can they be physically implemented.

Or, I guess they are just for the circuit simulation, not for physical layout.

I hope that someone help me soon, plz.

I am concerned about the layout... umm.. is it that difficult?

The models are described in detail in the ADS help. There, you can see the differences (number of ports and where the ports are physically connected to the ICAP).

Thanks for the answer. I already looked into it but it was unhelpful.
In the layout, MICAP3's port 2 is shaped as a colored line (meaning grounded).
I wish to know how to implement this ground stuff..

Have you looked at the footnotes? The ADS help describes what this ground is: it is a distributed "sheet" via to ground across the width of the ICAP. In your actual implementation, you might want to use multiple small circular vias instead of the "via sheet". Then, for best accuracy, EM simulate with your actual via configuration.

Thank you for your sincere answers. I have recognized what it is and how to deal with it. Now, I'm trying to approximate the model with several 'via' structures.