Is it possible to calculate a transmission spectrum from a plane wave excitation in cst studio? My experiement is in free space so i cant really use a waveguide port as it would change the experiement.
You can have plane wave excitation, and I think you can also plot the far-field scattering for this, which gives the directional spectrum. You can ask for far-field at different frequencies which will give the frequency spectrum. Probably the best way to get the frequency spectrum is with post-processing.