VNA GUI reference
R&S
®
ZNL/ZNLE
401
User Manual 1178.5966.02 ─ 19
By default, the reference impedance of a physical port is set to the reference impe-
dance of the connector type assigned to the port. However, it can be defined as an
arbitrary complex value (renormalization of port impedances). By changing the refer-
ence impedance, it is possible to convert the measured values at 50
Ω (75
Ω) into val-
ues at arbitrary port impedances.
For balanced ports, it is possible to define separate complex reference impedances for
differential and for common mode.
Balanced
port
Single-
ended port
Differential mode
Z
ref
= Z
0d
Common mode
Z
ref
= Z
0c
DUT
Single-ended
(unbalanced) port
Z
ref, default
= Z
connector
2
3
}
1
2
Physical Port
no.
Logical Port
no.
Analyzer
1
Balanced port:
Single Ended Mode / Common Mode / Differential Mode
Defines arbitrary reference impedances.
"Single Ended Mode" is available for single-ended logical ports only, "Common Mode"
and "Differential Mode" impedances for balanced ports only.
The default values for the balanced port reference impedances are derived from the
(real) default reference impedance Z
0
= 50
Ω of the (single-ended) physical analyzer
ports:
●
The default value for the differential mode is Z
0d
= 100 Ω = 2·Z
0
.
Meas softtool
