GUI Reference
R&S
®
ZNB/ZNBT
255
User Manual 1173.9163.02 ─ 53
Tip:
The default reference impedance of the physical analyzer ports is Z
0
= 50 Ω.
The default reference impedances for balanced ports are derived hereof. You do
not need to change this value unless you want to renormalize the port impedances;
see
Chapter 5.3.2, "Reference Impedances"
3.
Select the measurement parameters and the diagram areas.
Depending on the test setup selected in
, the wizard offers different sets of S-
parameters. Each S-parameter trace is displayed in a separate diagram. For trans-
mission parameters, the wizard always selects dB magnitude format. For reflection
parameters, you can select between Smith or dB magnitude format.
Tip:
You can always use the "Back" button to return to previous wizard steps and
modify your settings.
4.
Select the sweep settings.
, the
5.
Select the measurement bandwidth and source power.
Choose a typical
values. A smaller measurement bandwidth increases the dynamic range but slows
down the measurement. If necessary, select a smaller source power to protect the
input port of the analyzer.
Note:
The predefined bandwidths and source powers have been selected according to
the following criteria:
● The large measurement bandwidth ("Fast Sweep") ensures that the noise of an
S
21
trace at minimum source power and 0 dB attenuation is smaller than 0.1
dB.
● The default source power for a passive DUT ensures that the analyzer receiver
is in its linear range (no compression) if a passive DUT with 0 dB attenuation is
measured. The default source powers for active DUTs ensure no compression
if an active DUT with 20 dB or 40 dB gain is measured.
If the actual gain of the DUT is higher than 50 dB, then the default source
power of -40 dB is still too high. It must be changed after finishing the wizard.
6.
Perform a calibration (optional).
Allows you to perform a calibration. The "S-Parameter Wizard" proposes a full n-
port calibration of the test ports selected in
. Automatic calibration is also
possible (if a calibration unit is available).
Tip:
You can skip the calibration step (select "Finish now without Calibration") if one of
the following applies:
● A valid calibration is already assigned to the active channel
● You want to apply a valid calibration stored in the cal pool.
● You do not want to use a calibration, e.g. because the factory calibration is
accurate enough for your measurement.
Meas Softtool
