how can i get the input impedance of a structure in CST

hi
I'm trying to simulate a cavity radiator with CST.But there seems something wrong with VSWR. So i'd like to see the input impedance of my stucture. how can i get it in CST?
3ks a lot :)
regards

Mcaro -> Z matrix calculation.

Regards,

to asdfaaa
your reply does help! thanks very very much!