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.

 

based on the geometry we can have more than one mode excited in real life radiation.

Using online calculators which is the basis of your questions is incorrect you believe online calculators are absolute. You yourself based on your past questions should know by now. There's no substitute for the innovation of the human mind in being precise for calculations that are methodical and relevant to the particular application at hand. The answers you wish are among the equations that must be applied to the particular application. If this is your only source to educate yourself then it is a very poor source although your questions are advanced using online calculators will impede your knowledge. Because I must not only answer your question but to explain why using online calculators is a poor choice. I use online calculators because I know the answer and wish confirmation, from online calculators but when the answer comes up diametrically opposed to one another! Then who is right? And now you are lost. Restructure your question and the answer you will have.

 

I think you answered the post you did not intented.
i did not asked about online calculators

 

my mistake