Differential CPW Problem (CST MICROWAVE)

Dear All,

I have imported a Differential trace into CST MWS, and I am using "Time Domain Solver" to get S-parameters and TDR measurements; the Problem is that we are getting wrong results.. we have used Polar software and the impedance is 100 Ohm differential.. but the TDR in CST MWS show a 3 Ohm impedance.

I am new to CST MWS, it seems the CST setting are wrong... can you please take a look at the attached file and let me know what's wrong.

Thanks in advance,

Ballimo