using only a geometrical symmetry in HFSS
I want to simulate an antenna placed inside a metallic cavity in HFSS. The whole system has a geometrical symmetry. I wonder if it is possible to reduce the memory usage and the computation time by applying only a "geometrical" symmetry plane. I know that I could use an E or H symmetric plane, but since I don't know a priori which one to use (maybe there are several modes coexisting in the cavity at the operating frequency), I prefer not to use such boundaries.
That's why I wonder if I can use a "simple" geometrical symetry plane to reduce the complexity of the model. If it is possible, how can I do it?
Many thanks in advance for your help
Best regards
You should be able to, assuming the antenna itself can be reduced by a symmetry plane.
While serval modes could exist, only some will be excited by your antenna -- the ones that can be reduced by the same symmetry plane as your antenna.
Just make sure that the symmetry planes work for the antenna, and you should be good to go -- just assign perfect E or perfect H boundaries where appropriate.
Hello
Thank you very much for your reply.
However I don't know how to determine which modes can be present inside my cavity due to the antenna radiation.
Do I have to:
1/ assume the cavity modes independant of the antenna (and its radiation) placed inside. The modes only depend on the cavity configuration and the frequency of interest. I could then compute the modes, at the frequency of interest, by simulating the cavity with a "testing" antenna (small loop, small dipole, a punctual source...). Then I could determine the orientation of the E field vector inside. And hence the kind of symetry planes to apply afterwards with the actual antenna inside the cavity.
2/or if I compute the E-field vectors at the vicinity of the antenna when it is in free space, I can deduce the kind of symetry planes to apply afterwards with the actual antenna inside the cavity?
I guess the reality is more complex...
Thank you very much for your reply
The reality is usually more complex, unfortunately, but I don't think much more so in this case. #2 should be the correct process, although if you wanted additional confirmation, you could do #1 as well.
Good Luck!