corrugated waveguide using hfss

hi
i am designing a wave guide whose side walls are sinusoidal corrugated. the corrugation of the walls depend on several parameter parameter, one is called delta which supposed to be very small. i design a matlab code that generate the same result of hfss but only for small values of delta, and an upper bound on value of delta need to be known by comparing the figures from both matlab and hfss. the problem is for matlab it take values for example 0.01 but in hfss it start works correctly from 0.06.

is there that can make it work correctly
regards

Hi
I couldn't find out what kind of parameter delta is, but you can define the delta in project variables and then use it in optimization.

Try setting up a fine seed mesh, it may be convergence.