Greetings all,

In a project I am designing a cassegrain antenna.

To do so, I already setted up the bidirectional hybrid simulation (3 iterations) in which I am designing a reflector+a circular waveguide with feeder. The reflector has been already developed and will use an integral solver. On the other hand, the circular waveguide with a feeder will be simulated with the transient solver.

If I excite only one TE mode on the waveguide, there is no problem with the results. But how could I evaluate the simultaneous excitation of 2 phi-angle perpendicular modes with the time-domain solver?

Because if I opt for the normal way of multi-mode excitation in the waveguide port of the feeder I defined (having inserted the desired angle and 2 as number of modes) I don't get what I am looking for. When I go to combine the two far-field results, CST says me that they are somehow "talking" with each other like if they are not purely perpendicular in phi angle.

Do someone has a fix/walkaround about this issue?

Mattia

CST Studio Suite ​​​​​​​