For HFSS, it uses FEM method. the frequency solution is the estimed frequency you want for your antenna application. I advise you not to make simulation on the whole band frequency. it will be less accurate but divide the band into subbands.

for a given band, you prefer an arithmetic mean

Generally, the frequency solution is the esteemed resonant frequency of your antenna, or the center frequency of your band in the case of a wide band antenna.

the solution frequency of the antenna is the frequency for which u designed the antenna.. that is your resonant frequency..  for frequency sweep, u can give the band in which your resonant frequency will come as the center frequency.

For wideband structures, it is better to set maximum frequency of the sweep, but for resonant structures, it is recommended to set the resonance frequency as your solution frequency.

Good luck!

It depends on the sweep type you are using. For narrow band structure the fast sweep type is recommended and in that case solution frequency will be your resonant frequency. For wideband structures interpolating sweep is preferred and in that case the maximum frequency of your sweep is your solution frequency. Discrete sweep is the most accurate but time consuming sweep type if you are doing discrete sweep you can keep any solution frequency( resonant or higher)

Hello

You can open your project in HFSS software then do the steps below: 

1- In the hfss bar menu, click on HFSS , you will have a list.

2- Click on Analysis setup .

3- Then click on Add solution setup...

You will have the solution setup icon, where you can change or enter your solution frequency.

Good luck my friend.

My answer is right and would probably be wrong. My answer is wrong and would probably be right.

Underneath you can see a pictures.

If ultra wide band is for 1GHz to 50GHz then what would be solution frequency for simulation in HFSS?

26GHz for discrete analysis.