Resonant Cavity in HFSS

Hi
Is it possible to run solver at particular frequency (or do a sweep frequency which is better) but without determining a port of excitation? Such like in eigenmode.

No: if there's no excitation, nothing would happen. Why would you even want to do such a thing?

I want to look what is the distribution of fields when I power with particular specific frequency. When I do eigenmodes I don't need to point excitation. I want to do something like eigenmode but at frequency specified by me. In FEKO it is possible

Electromagnetic power propagates in modes: discrete forms of electric and magnetic fields, determined by the structure and surroundings under observation. "power[ing] with particular specific frequency" does not mean anything, as frequency is not equivalent to power.

Do you mean exciting your structure with an incident plane wave?