HFSS instantiate design in a design

Hi,
I've the design of an antenna and the design of the SMA connector. I'd like to instantiate the SMA inside the design of the antenna. How can I do this? Cant find a way to do it...
Thanks

To my best knoledge, the only way to do it is by going to one model and copy all its conten, and then past it to the other mode