Coaxial feed with slot antenna

Hi everyone! I need to connect the coaxial feed with a slot antenna...I used a parametric surface as you can see in the picture but it doesn't work...How can I solve the problem? Thank you
In the picture you can see the lumped port on the coaxial feed and I used every surface as a PEC.

Thanks, do comments please because I am new to this and I need to learn more about.