CST Microwave Studio - Axial ratio using s-parameters

Hi everybody!
I have had some problems while i simulated an OMT. Port number 1 is a circular waveguide and port 2 and 3 are rectangular. I dont know how I could calculate the axial ratio in port number 1. I know i can obtain the axial ratio using post processing and farfield but what i'm trying to do is to use the results of my s-parameters to calculate it (without exporting it to Matlab). Is it possible?
Thank you all.
Bye.

Hi,
I don't think that is possible to calculate the axial ratio from s-parameters if you don't know the E-fields map from your wave-guide modes...
BR

what is the OMT ?

@ferdows: http://en.wikipedia.org/wiki/Orthomode_transducer

But how can i do to obtain the E-fields in my circular wave-guide and not in far field? Then, there is any form to use the results of the s-parameters to create an equation?
Thank you.

Hi,
Maybe you could use the 'E-field monitor' in CST MWS : then you can extract the E-field components with post-processing...
Good luck...

which type of equation u want to extract from S parameter ?