Slotted ground plane boundary condition problem in HFSS

Hi All,

I am new to HFSS, and trying to simulate a ring patch antenna with four rectangular slots in ground plane. I drew the four slots and subtracted them from the ground plane ( the ground plane is a sheet with a 'Perfect E' boundary condition). It seems like the program does not 'see' the slots. Just wondering if I need to assign any boundary to the slots, if so, what should that be? Or what else can I do?

I also used a radiation box under the slotted ground plane, is that OK to do that?

I have attached the geometry.

Thank you in advance.

How did you figure out that HFSS is ignoring the slots ?

To answer your question - You can assign Perfect H boundary to the slots. Do not subtract them from the ground plane. When Perfect H boundary is internal - It behaves like a aperture. For more info- See HFSS Help

Yes, Radiation boundary mimics free space.