I am using the 80SSPAR software and the Iconnect S-parameter Wizard software and only getting 4 GHz (frequency range). Why don't I get a higher Fmax frequency?

I am using the 80SSPAR software and the Iconnect S-parameter Wizard software and only getting 4 GHz (frequency range). Why don't I get a higher Fmax frequency?

The available frequency range is determined by the risetime of the reference waveform.  To get faster risetime, use shorter SMA cables and shorter traces on the test / cal fixture.