Different S-parameters with Ansoft Designer and Agilent ADS

Hi,

I am simulating the same circuit with Designer and ADS and am not finding the same S-parameters... The core of the model is a 112 ports S-matrix stored in a Touchstone file - the same file is used for both simulations of course, using the S112P_Diff component in ADS and the standard SnP with differential ports in Designer.

My circuit is quite complex and it's possible I messed the design in one of the software, I spent considerable time checking that both models are the same though. In general however, what could explain significant differences (i.e., > few percent) between S-parameter simulations with different software? The ports have to be read in the same order in the SnP file of course, but I am assuming that both Designer and ADS read Touchstone files the same way. What about the model that's used to fit the data - again I doubt it's a problem since I am only plotting the S-parameters on the data point, not in between, but we never know- ? What about issues of non-passivity, return path to ground etc...?

If anyone has experience with this and has suggestions on how to make both simulations agree, other than checking both models again and again - please let me know!

Thanks,

Bastien

Hi bastpg,
while working with data files (such as SnP in ADS), interpolation is done by the software to provide as desired result. Kindly check it in ADS and Ansoft Designer, weather interpolation options affects your simulation.
Hope this helps...