How to get the freq-wavenumber diagram for EBG in CST.

freq-wave number

Does anyone know how to get the ω-β diagram for EBG structure (like the picture below) in CST 2007. It also be called as dispersion diagram. I've searched in this forum but this topic still hasn't had a clear answer.
I'm looking forward to a reply and thanks in advance.

how to get the wavenumber

In the figure, there are 2 curves which named as freq mode 1 and freq mode 2. I wonder if they are correspondent to TM and TE wave or not. When simulating in CST, for freq mode 1, 2 or so on, in eigenmode solver by choosing add watch/freq mode... we have 2 curves simultaneously. However if they are TE/TM we must change the boundary to Et/Ht in z+ plane and get the 2 result curves sequently. So I don't know what the correct method is.
when running in eigenmode solver, each time we will get a piece of the result curve (Γ-X, X-M, M- Γ). Each result is showed in the Table (freq mode 1) in the Navigation Tree. But I don't know how to save the result for each simulation, for example we have just had the Γ-X and now want to have the X-M... I right click on the 1D result folder and Add new tree folder but they didnt work. please help me.