[error] Fast sweep setup, process abc3d

I'm trying to analize a coaxial to circular waveguide transitions and when I try to do a fast sweep, HFSS shows the next message:


[error] Fast sweep setup, process abc3d : "LumpPort1" mode 1 crosses cut-off in the specified fast sweep range. Consider splitting the sweep into multiple ranges. Use a port-only discrete sweep to locate the cut-off frequency.

What does this mean?

Thanks and Regards.

Hi,

In Waveguides use waveports. Set more than one mode, and you wil be able to see the frequency ranges of each mode.

Itai

hi
why more than one mode should be used? what is the advantage?
thanks.

I am Analysing a coaxial to rectangle waveguide transitions and I am using rectangles for aproximating the coaxials. The design doesn't permit me using wave ports (I think. Please, see the design). What can I do?, Could I use wave port in this design?, How?.

Regards and Thanks.