Hi Cherne-he,
I assume you are trying to excite a TEM mode, where your reference to TM and TE just specifies the direction of the electric field (the optical definitions). If this is the case:
- The electric field direction is specified by the integration line. Rotating it 90 degrees in the plane normal to the propagation direction will give the "other" polarization (TM or TE).
If this is NOT the case (and you are using the RF definitions of TM and TE):
- Exciting additional modes at the port (specify at least 2) will give you the modes that you're looking for.