coax to monopole antenna interface

Hi I am new to HFSS and I am trying to simulate a monopole antenna fed from a typical coaxial cable. Does anybody have a suggestion or an example for guidance?

Typically the coax is placed under the groundplane (connect shield and groundplane) and the center conductor becomes the monopole (sometimes as a "fat" rod).

If you can, the ground plane should be around 3-4 wavelenghts in diameter. Jasik has a figure showing the elevation pattern as a function of the ground diameter vs elevation pattern. It is worth running down and studying.

Thanks for the handbook suggestion. I have ordered it from the library already, it seems quite helpful.