Convergence Problem?

I am learning about EM Simultor. And one of the big problem often comes is :
The convergence problem.
Can somebody help me to understand what is it?

Thanks

Hallo,

the mathematical algorithm, your em tool uses for solving the field problem
in a numerical way did not converge to one definitive solution.

You See. It's a rather general error.

The way you set up the problem doesnt lead to a solution.

Thanks elektr0

But If the sofware converge to one solution, it may not see other solution (or part of it)
Also if using differential equation you need to find the proper constant...

hi

if the solution doesnt converge you can increase NUMBER OF PASSES in the menu you
select operating frequency and MAX ΔS PER PASS .
default=3
a better choice=6 even 9

I would recommend using more than 3 adaptive passes as a default. For HFSS, I usually set deltaS to 0.005 and maximum number of passes to 10 or 12. Check the convergence before viewing the results. It is a good habit to get into.

Also remember that converging on input impedance is no guarantee that the radiation boundaries (and therefore gain, radiation efficiency, etc.) have been adequately sampled. This is a common mistake when analyzing radiation problems.