Help! hfss err: Typically a lumped port contains 2 conductors ...

Hi, I want to design a patch on the outside surface of a cylinder(Please check the attached file), it includes only one port, which connects the inside and outside surface.

Then I get an err:"Fast sweep setup, process hf3d: '1' conductors touch lumped port '1', typically a lumped port contains 2 conductors. Please verify conducting boundaries and objects are correctly assigned and touch the port. If a Radiation boundary touches the port and it is desired for use during the port solution, select 'Use Radiation Boundary on Ports' under the Advanced tab in the Solution Setup"

the air box is larger than the substrate, so I don't what's the problem, Please help me, I really need your help! Thanks a lot!

The lumped port does not touch the ground. Try to extend it

Thanks! I understand it: the inside and out side of the surface should be circular, but it is represented by polygons, so the radius of the inside surface is not 77mm which it should be, so the port does not touch the ground.
Now I don't konw how to let the port touch the ground, I try to draw the port and let it connect the ground directly, but I can't get the exact radius of the inside surface at that point.
May you tell me how to do? Thank you very much!