How to drawing Rotman Lens with HFSS or Autocad

Hi,
I am working in Rotman lens antenna. i want to know how can i draw it in HFSS and i hear that it is very difficult to do that .
i have been started to draw it but it was very Creepy.
So , i have read that it is simple to draw it by AutoCad and then import the dxf file in HFSS.
There is any help for Rotman Lens Drawing?
either HFSS or Autocad drawing?

Thanks in Advance.

Hamada.