HFSS problem!!!

Hi!
I have the problem of HFSS 9.2. I simulation a monopole antenna and get the reflection coefficient and radiation pattern. But I can not use 3D polar plot to get 3D field. I ever use smae way on dipole and it is no problem.
Do anyone help me!

Thanks

Hi,
Check if you defined at least one radiation boundary and properly defined a Far field sphere for the far fields and also if you saved the fields forthe frequency for which you need to plot the pattern.

-svarun

I have the same problem.
So how do I define a far field sphere?

will some budy plz tell me how to increase the bandwidth of PIFA antenna...and example if...

thanks