How to find out resonant freq in HFSS?

i m using HFSS 9.2 and i have to find out resonant
frequency of a copper ring using eigenmode ..

i have tried it but HFSS is giving a warning that

"Solving inside solid with such a high conductivity
would require a large mesh..."

so how to create this large mesh..

i have reduced the length of tetrahedral elements
using length based mesh analysis but of no use...so
please guide me in this matter.

with thanks

Do not solve inside the metal unless you are very worried about conductor loss or that the metal is thinner than the skin depth. Just uncheck solve inside for the metal ring.