single mode Simulation of an antenna in CST

[yefj]

Hello,generally when we simulate an antenna using a waveguide port its set by default in excitation of 1 mode.
But how its makes an accurate simulation of a far field.
for example in a patch antenna basickly its a parralel plate waveguide.if we set a far field probe at 5Ghz
based on the geometry we can have more than one mode excited in real life radiation.
How setting the waveguide port to "1 mode" as shown bellow make an accurate sumation of an anttena?
Thanks.

 

[PlanarMetamaterials]

I think you are confusing excited modes of a source with the various resonating modes of a structure. The variable you're indicating there is the number of different modes excited by the source, for example, just the parallel-plate TEM mode.

This is independent of how the structure responds to such an excitation.

 

[yefj]

Hello,exactly why we excite only one mode by the source.
I know that there is a dominant mode,but how CST know to choose to excite the correct dominant mode?

 

[PlanarMetamaterials]

Im not sure what exact process in uses, but essentially it guesses -- unless you tell it otherwise.