Simulation problem with shorting pin

I am simulation a paper attached using CST. Results are quite different especially with reference to return loss even with adaptive meshing.

Also tried with discrete port but no where near the fabricated results.


Regards!

Please have a nice look at
ahttps://www.edaboard.com/viewtopic.php?t=80010&start=0


It seem that CST or HFSS have problem with waveguide ports as results are not similar to alreasy meas one.

Any suggestion is highly appreciated.