Guilin Sun
Ansys Employee

This is due to the fact that when the object dimension changes the mesh will change. So if you monitor the field quantities then the matrix will change. To aovid this, you can use an override region to cover the largest region for your sweep.

One note: usually it is not necessary to extract the near field spatial distribution. for a waveguide, you may need to monitor other quantities such as neff or transmission/reflection.