Imitate the radiation pattern of an antenna

Hi,

I am quite new on Comsol and i am trying to imitate the field emitted by the radiation pattern of an antenna.

In other words, I have a radiation pattern antenna, and I would like to have the same field on COMSOL without importing the geometry of my antenna.

I have read all the models of the library but i have not yet find the good way to do it.
Someone has any tips for me?

Cordially,
Xavier