placement of radiation boundary for a chip enclosure

I have a simulation model in HFSS that consists of a printed dipole antenna on a substrate but enclosed with a cover ( ceramic material). Such a model is to emulate an antenna inside of a chip.

I am not sure whether to place the radiation boundary at the outer faces of the cover or create an air box surrounding the model and place the radiation boundary on the faces of that air box.

I would really appreciate your input and feedback.

Attached is a a cross section of the model.

Thanks!

Hi wr233608,

You generally want the radiation boundary at least 1/4 wavelength away from the nearest radiating edge, which could include the ceramic in this case. So you want an air layer around the outside of the cover for best results.