Thanks for responding guys@vks & @Evan Merkel. This helped me a lot.. but im still facing some challenges..
I have the data from Sonnet software, but the data file is not in the same format as the SP file. I tried to convert it to the correct format, but I encountered an error during simulation: "an error on line 2: syntax error."
So I tested simulating with an exported S-parameter file from Cadence, but I encountered the same error.
Could you please check with me if there is something I should consider?