hfss boundary condition

If I have antenna inside box 1, then both antenna and box 1 are inside box 2.

For HFSS simulation, do I need to subtract box 1 space from box 2? Please advise.

I did simulation with and without subtraction, the results were the same.

Thank you for help.

you need to subtract ( with keep clone) option.
other wise HFSS will give error.
What is the material for your boxes?
If they are same then why are you drawing two boxex?!.
How result wil lchange for two boxex of same materials?

Abhishekabs:

Box 1 is air and box 2 is sand, then both boxes are inside air radiation box.

I tried to subtract box 1 from box 2, the simulation results are the same with or without subtraction.

I talked with HFSS support. They said if there is not intersection on the two boxes. then you don't need to substract.

Please try an experiment for yourself and let me know. Thanks.

In this HFSS project files you may be find something usefull about your questions

Give me some time. I will let you know.