CST : Deembedding Discussion

Hi Forum,

deembedding in CST MWS 2009 is an easy way of getting
the signal phase inside your structure. However, I observed
some real issues with this tool:

If you have a structure, (micro strip , waveguide, etc.) with
two ports , in and out, and try to set the reference plance
of both ports to the middle of the structure, the phase should
be angle(S21)=0 degree. This is because the 2 reference planes
are on the same plane!

In CST I do not get this result, never!

Does anybody know this issue and resolved it ?

Thx. F.