How to simulate a dielectric immersed antenna in hfss

I have to simulate an antenna immersed in a dielectric.
what is the distrance for the dielectric box (radiation)? i noticed that the gain changes according with the distance...

You want to keep effective lambda / 4 for radiation boundaries and effective lambda / 10 for PMLs. However, if you want correct far field patterns, you will need to go to HFSS -> Boundaries -> Edit Global Material Properties and change the global material from air to whatever the immersed medium that the far field will be measured in.

Have Fun

Tallface

---------- Post added at 19:17 ---------- Previous post was at 19:17 ----------

Also, be aware that if your immersed medium has loss, it will matter ;)

thank you very much!