How to choose the waveport size and the boundary size for bandgap transmission line?

I am trying to build a bandgap transmission line(CPW (w=0.2mm,g=0.1mm,h=0.5mm,ξ=11.6)), but I donot think the result is correct espacially above 30 GHz. I think there are some problem in my defining of the size of waveport.

Could you help and tell me how to choose the waveport size and the boundary size, and also which kind of boundary should I choose, perfect E or perfect H?

Thank you very much!

If you are referring to HFSS analysis, the waveport for a CPW feedline must contact the side grounds in order to set up the proper modes on the line. The bottom boundary should extend down to the groundplane if it is grounded CPW and past the dielectric bottom if it is ungrounded CPW. The recommended port width is 3*(2g + w) and minimum port height is 4*h.

Be careful not to make the port width greater than λ/2 in any direction or a waveguide mode will also be supported.