Why is differnt S parameters between HFSS and ADS?

Hi friend,
Anyone has experiment about different s parameter between HFSS and ADS?I simulated a passive filter in HFSS,and export the S parameters into ADS,I found the parameters are quite different.Can anyone share us the experience how to get the consistent parameter?
Thanks

Can you show us your setup & results?
How much difference you have found?

There shall be no difference analyzing an exported S-parameter file by a different CAD simulator.

I understand to be slightly differences in results when doing separate simulations, for the same circuit, using different CAD simulators.

Thanks,friends.i find the root cause.as what both of you said,it is the same.

Jeez, and just wait until you actually build and test it!

OK,Thanks!