Help: HFSS port problem-no conductors

Hi, dear all,
When I am using the HFSS v11, one error occurs and I cannot assign port.
The error information:

No conductors were found on port, so auto assignment of conductors on that port cannot proceed.


In the model, I use Vacuum and do some operations like "unite", "subtract", and thus there should be conductors since the boundaries are pec. Also, I define some parameters. Somebody seems saying that due to the definition of parameters in the model, the above problem occurs.

How to solve this problem. I have nearly ten parameters in the model. I don't want to remove them.

Waiting the resolution online.

Thanks.

Hi y99lx
you can't assign excitation on the boundary that it's perfect boundary
(total reflection)

thanks. But i don't think so.

y99lx.