hfss waveguide

Hi,

i want to mesh the reflection and transmission of a normal rectangular waveguide.

Frequency 50GHz

Length 20mm
Heigth 2mm
Width 4mm => Cut-off-Frequency is 37.5GHz

Normaly the reflection under the Cut-off-Frequency has to be 0 db but Hfss show me a S11 factor of -60 db. This cant be right and i believe my misstake handles about the waveport settings. I do not Renormalize. But when i renormalize for example of 570 Ohm ( the Zf of 50 GHz) , the values under the cut-off Frequency and at 50Ghz are rigth but at all other frequency it is wrong because the programm calculates Zf=570 Ohm at 40GHz and 60GHz what is definitiv wrong.

So can somebody teach me, how i can designing a rectangular waveguide with the rigth settings for S11 and S21...please

thanks...

would you please upload your file!

Hi,

here is my Project.

So the Problem is the Parameter S11. Under the Cut-off-Frequency, the incident Wave has to be reflected by 100% so at 0dB, but not in hfss...why? Belive something wrong with Z0.

2. Question: What is the reason for the ripple between 40 and 70 GHz. I has expected a even rising line. Maybe it deals with the mesh refinement?

Where are my misstakes?

thanks..

Project was designed by hfss v10

Hi jonny1
I dont have access to HFSS right now but I can recommend you one thing.
Check the HFSS tutorial for waveguide simulation.
May be you will find what is going wrong.
Example shows how to excite waveguide,& do port setttings.
You will findwave guide tutorials in this forum or google it.