Dispersion diagram in CST 2014

Hello everyone,

I am trying to simulate a unit cell by eigenmode solver in CST 2014. I use steps as: "Eigenmode solver -> Parameter Sweep -> Results Template -> 2D, 3D Field results -> 3D eigenmode result". I obtained the plot of "frequency vs phase". My question is: How can i obtain the final dispersion diagram (frequency vs beta)? Is there a way in CST to get 1D dispersion diagram results or Do I have to make some calculation starting from frequency vs phase diagram?

I have read most of threads here, but i am not able to do it.
Any help would be great.
Thanks.