Hi.. I want to ask how I correctly Identify the number of floquet modes in the port for my structure in CST studio 2022 frequency solver?. I notice that when I increase the number of modes in the port the S parameter spectrum result starts to change but I don't know if I should trust the results or not, if anyone knows the formula or the rule for setting up the floquet mode correctly, kindly let me know. Thank you. Apologies if I am posting in the wrong community 

CST Studio Suite ​​​​​​​