Critaria to define meshing in HFSS

Hello
and sorry for my english

I'm designing an IFA 868Mhz with HFSS, and I would know how we define the meshing for simulation and how we assign it
--it is preferable to use the defaults values?
for assign meshing operation: we assign it just for boundaries or all the design (cooper, substrate)

-- for sweep: solution frequency: is it in my case 868 Mhz, or I can chose an other frequency

many thanks

If you don't kow very well how to use it, default mesh is a good option in my opinion.
Solution frequency is your frequency of interest, in your case 868MHz.

10x for your answer

I have an other question, how I can verify the convergence after simulation?

In your design go to Results>Solution Data. A window with differece tabs pop up. One tab is convergence.
There you can find Convergence, in my opinion is easy to look for the plot.

I have to say that in the Analysis Setup I always select : Options>Adaptative Options>Minimum Converged passes: 2. (Maybe it is by default)

I 've tried with solution freq 868 MHz but I didn't get the right resonant frequency but whith freq solution =200 I get it,
!

S11 is only -13db how can I get the right value of S11 knowing that Ive already simulated the same antenna with ADS and I got S11=-30 db

ADS is a method-of-moments based solver and ideally suited for 2D applications. HFSS is a frequency domain solver and can handle complex designs better than ADS Momentum. Differences between the two solvers are expected.

Think of your solution frequency (or rather its wavelength) as determining the size of the mesh cells. The higher your solution frequency, the more dense your mesh will be.

If your antenna is supposed to work at 868 MHz, then do NOT set your solution frequency to 200 MHz. If you set to 200 MHz, the answer might not be dependable/accurate.

Check the impedance of your input port, or the re-normalization value. It will depend on whether you use waveguide port or lumped port. This might be affecting your S11 values.

Take into account that in ADS Momentum Ground plane is infinite,not the same in HFSS, so as jeedur says, a difference is expected.

I know that ADS uses an infinite Ground plane, but in my simulation I ve introduced my own ground plane and with this methos we can have a finite ground plane