First of all, many thanks for your prompt response.
It would be excellent to get the possibility for calculating TE and TM modes of dispersive waveguides. TE and TM as it will allow to calculate every possible mode in hollow waveguides.
The simulation is very helpful for using the scattering matrix approach (first order approximation) for calculation of e.g. microstrip to waveguide transitions or cavities or taper etc.
The simulation is quite simple as shown in attached picture. I did this by using the “old” QUCS.