HFSS - unite two materials

Hello,

I'm doing a simulation in HFSS 14 and I have a doubt.
I have two overlapping structures of different materials (say material_1 and material_2). When I unite the two structures the resulting body has either material_1 or material_2 dependeing on the order in which I unite them. There's a way to have a resulting structure maintaining each component's material?
Thank you.

Best regards.

no method for this because no one need to do that and if u want to adjoin to material u should place them in vicinity and avoid to overlap of them and u dont need to unit them

I'm a bit puzzled how best to handle two touching, but different materials. Lets assume material 1 extends for 0,0,0 to 0,0,1, and material 2 should go from 0,0,1 to 0,0,2. Do you end 1 at 0,0,1, and start 2 at 0,0,2, or perhaps have a very small gap between them, even though they are supposed to be touching. For example, should 1 end at 0,0,0.99999999 and 2 start at 0,0,`1.0000000001 ? I wonder what happens with rounding errors in the floating point processor some times.

Deborah

whats do u mean ? u mean we should combine material together?

Hi ferdows,

I have the following scenario. I have an antenna connected with a coaxial cable which ground is made from tinned copper wire. This ground, through connectors and PCB touches a major structure made of aluminium. I want to know how much this connection could affect my antenna but in HFSS I only have the option to have everything made of either aluminium or cooper. That's why I want to know if there's possible to have different materials.

Best regards.

Then you do exactly this. You can zoom into that edge and then you should see that the materials are touching each other without a gap.

Mersault, what behaviour do you expect when you unite two overlapping structures? Compare with reality, there you can only have material1 or material2, but not both at the same position.

as flanello said u should design with out gap and with out gap dont worried about result truth and attach a model patch antenna with coaxial here i hope it helpful for u and others

Hi,

I didn't know that designing without gap could serve. I believed that the "electrical" interaction could be only reached making a explicit union of two structures.
Many thanks for the help.

Best regards.

Instead of having a circular shape (from the coax) just touching the surface at one point (=zero area), it might be safer to add some extra, overlapping metal that ensures connectivity.