4 port rectangular waveguide switch

Hi,
Can anyone help me design a 4 port rectangular waveguide switch in CST microwave studio?There is no example given in the tutorial.I tried designing it,but the s-parameters are showing erroneous results.

Can you please explain a bit what you mean when you say four port rectangular waveguide switch? Do you mean four port circulator ?

I am attaching a photo of the waveguide switch