antenna wire simulation rfid hf
Hi Artem -- Going from 10 mil (about 0.254 mm) thick to 1 mm thick is a big change. If you keep the same 10 mil gap, you need more sheets in the thickness model.
For your original circuit, 10 mil gap and 10 mil thick, usually 2 sheets is plenty. This puts a sheet of current on top and a sheet of current on the bottom to model thickness. We recommend 2 sheets when gap and thickness are about the same.
For 1 mm thick, I think you might need at least four sheets because the gap is 1/4 the thickness. The way to find out is to include more sheets and see if the answer change is significant.
There are many different thickness models, and they all have advantages and disadvantages, as discussed in several threads elsewhere on this forum. Keep in mind that when anyone says that their model is nearly perfect, they are speaking as salesmen, not as engineers.
I did not use em simulation software before. Could we trust the simulation result ?
NEVER trust any software or what any person (including me) says! (In God we trust, all others must have proof!)
First, all EM analyses give the wrong answer. Every single one of them. This is absolutely 100% guarenteed. Anyone who says an em analysis gives the right answer is doing sales. When they say the answer is right to within X%, and they have some data to backup the X%, now they are doing engineering.
The way to figure out X for Sonnet is to repeat the analysis and cut the cell size in half. If you are using thickness, double the number of sheets. The percent difference between the two results is X.
This called convergence analysis. If thickness is important, it is critical to refine the thickness meshing too!
Just had another thought. The box sidewalls might be close enough to lower the resonant frequency. You should also try doubling the size of the box (keep the cell size the same) and see how things change.