waveguide port of hfss?

it is not WAVEGUIDE port, but WAVE port! It feeds waveguides and all kind of transmision lines ( microstrip lines as on the picture)

I actualy prefer lumped port, for microstrip lines. wave port often gives acuracy problems.

actually, the results of simulation using lumped port and wave port have small differences. That means both can be applied for ML, provided that single mode propagation is considered.

choosing waveport or lumped port for any design is really a little complex problem. anyway my opinion is whenever ur design is with in some boundary then u shall choose lumped ports for the same and if the design is external to any boundary then u shall choose waveports. this is what hfss specifies. anyway choosing waveport or lumped port doesnt matters a lot, it causes very small difference at last.