VNA calibrated by 50Om - nominal port impedance
On measure S parameters possible calculate get Z parameters (by known Z0 = 50)
Next possible calculate from this Z new S` parameters but use Z` != 50 Om
This process named as renormalization and allow see now DUT work on other system impedances
This work on all S11 and S21 - so possible see how work filter on non 50 Om systems, or see SWR for 75Om and so on
