HFSS Eigen or Driven Mode to find Resonant Frequency?

Hi,

I want to find the resonant frequency of a DGS structure. But HFSS is showing two different results, one for Driven modal and the other one for Eigen Mode. Can someone say which is the exact resonant frequency and why there is this deviation?

I am yielding 5GHz in Eigen mode (mode1) and 6GHz in Driven modal solution.

Can anybody help me in correcting this error?

It will be hard to tell without looking at the design. But based on the help on HFSS, both solution types should produces similar resonances.