SMA connector CST modeled

I am trying to model and simulate the effects of a SouthWest Sma connector. Design is quite simple, two connector and a piece of coplanar microstrip. I don't know what I am doing wrong, but I get very bad results, very far from the desired ones.
It is modelled in CST, I have checked boundary conditions and probably it is where the problem is. I would appreciate your help.
Thank you in advance.
Clara

Just a general observation:
You may have nothing wrong with the simulation and it may be accurately describing the situation. I would suggest two avenues to explore. Build and test a sample if that is practical and/or simulate the same situation in another software package. that may aid you in deciding where things are going wrong.
Coax to CPW transitions are not trivial, particularly as you get well into the microwave band. You may also need to consider vias and a lower groundplane.
I cannot speak directly to CST issues as I use a different software suite.

hi clara,
if u had solved this problem plz send me ur CST file
best regards