Discrete Port Defintion in CST

Hello,
Has anyone ever worked with the discrete port in the CST enviroment.
When yes, could u please give me some suggestions on the definition and also some examples, thanks a lot :)

I used to use discrete ports for microstrip antennas simulation.
I select two points and define the discrete port between them.
In the attached file you can find a microstirp filter with discrete ports.
Bye