Concepts and Features
R&S
®
ZNB/ZNBT
121
User Manual 1173.9163.02 ─ 38
Unbalance-balance conversion avoids the disadvantages of real transformers:
●
There is no need to fabricate test fixtures with integrated baluns for each type of
DUT.
●
The measurement is not impaired by the non-ideal characteristics of the balun (e.g.
error tolerances, limited frequency range).
●
Calibration can be performed at the DUT's ports. If necessary (e.g. to compensate
for the effect of a test fixture), it is possible to shift the calibration plane using
length offset parameters.
●
Differential and common mode parameters can be evaluated with a single test
setup.
4.3.5.1
Balanced Port Configurations
Defining a balanced logical port requires two physical ports.
All physical ports (on the VNA and connected
) are equivalent
and can be freely combined. Moreover, it is possible to assign arbitrary, independent
reference impedance values to each unbalanced port and to the differential and com-
mon mode of each logical port.
Measurement Results
