Concepts and Features
R&S
®
ZNB/ZNBT
129
User Manual 1173.9163.02 ─ 53
●
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.
5.3.6.1
Balanced Port Configurations
Defining a balanced logical port requires two physical ports.
The physical ports (on the VNA and connected
lent and can be freely combined to balanced (logical) ports. Moreover, it is possible to
assign arbitrary, independent reference impedance values to each unbalanced port
and to the differential and common mode of each logical port.
Example:
2 physical ports
: Reflection measurements on 1 balanced port
Bal.
port
Differential mode
Z
ref
= Z
0d
Common mode
Z
ref
= Z
0c
DUT
Balanced port:
Log.
VNA
port
3 physical ports
: Reflection and transmission measurements on 1 balanced port
Bal.
port
Differential mode
Z
ref
= Z
0d
Common mode
Z
ref
= Z
0c
DUT
Balanced port:
Log.
VNA
port
Single
ended
port
Single-ended
(unbalanced) port
Z
ref
= Z
connector
4 physical ports
: Reflection and transmission measurements on 1 or 2 balanced ports
Bal.
port
Differential mode
Z
ref
= Z
0d
Common mode
Z
ref
= Z
0c
DUT
Balanced port:
Log.
VNA
port
Single
ended
ports
Single-ended
(unbalanced) ports
Z
ref1
= Z
connector1
Z
ref2
= Z
connector2
Bal.
port
Differential mode
Z
ref
= Z
0d
Common mode
Z
ref
= Z
0c
DUT
Balanced port:
Log.
VNA
port
Bal.
port
Differential mode
Z
ref
= Z
0d
Common mode
Z
ref
= Z
0c
Balanced port:
Log.
VNA
port
A balanced port configuration is defined in two steps: First, select the pairs of physical
ports that you want to combine to form balanced ports. Second, define the two refer-
Measurement Results
