EME Solver Selecting TE vs TM modes for Rib Waveguide
I am going through the 1x2 MMI example provided by Ansys. In order to calculate S-matrix for TE and TM polarizations, the example simply selects symmetric and anti-symmetric boundary conditions on z min bc. In the provided example, the waveguide is a strip waveguide and I sort of understand why this work. In my case, I am using a rib waveguide which is not symmetric across z-axis. How would I for the EME solver to select TE or TM modes separately in order to extract s-matrix from the parameter sweep?
Rib waveguide for my simulation the structure isn't symmetry across z axis:
I am stuck and couldn't find a way forward. I have tried several different options, such as selecting user defined modes on the input and output ports and select them all to be TE or TM, but the S-matrix I get from that run is very different than what I get using the symmetric/asymmetric z min bc (even for the strip waveguide). Any help would be appreciated.