Concepts and features
R&S
®
ZNB/ZNBT
197
User Manual 1173.9163.02 ─ 62
larger bandwidths are restored after the sweep. The analyzer measures the power at
each sweep point, compares the result with the nominal power of the source, and com-
piles a correction table.
At the end of the calibration sweep, a checkmark symbol next to the calibrated source
indicates the status of the measurement receiver calibration. After a change of the
sweep points or sweep range, the analyzer interpolates or extrapolates the calibration
data.
4.5.6.3
Power calibration labels
Power calibration labels in the trace list for wave quantities and ratios inform you about
the status and type of the current scalar power calibration. The labels appear in the fol-
lowing instances:
●
For a-waves, if a source power calibration is available.
●
For b-waves, if a measurement receiver power calibration is available.
●
For ratios between a- and b-waves, if both a source power and a measurement
receiver power calibration is available.
Calibration of S-parameters
S-parameters and derived quantities (e.g. impedances, admittances, stability factors)
are assumed to be linear; otherwise they must be corrected by a SMARTerCal.
Therefore, a scalar power calibration is not applied to S-parameters and derived quan-
tities; no power calibration labels appear in the trace list.
Table 4-14: Power calibration labels
Label
Meaning
PCal
A scalar power calibration is available and applied without interpolation or extrapola-
tion (see below).
This means that a set of measured correction data is available at each sweep point.
PCai
The power calibration is applied, however, the correction data for at least one sweep
point is interpolated from the measured values. This means that the channel settings
have been changed so that a current sweep point is different from the calibrated
sweep points. It is not possible to disable interpolation.
PCao
The power calibration is applied, however, the source power (channel base power)
was out of tolerance.
PCax
The power calibration is applied, however the calibration data is extrapolated. The
current stimulus range exceeds the calibrated stimulus range. The power calibration
data of the first calibrated sweep point is used for all smaller stimulus values; the
power calibration data of the last calibrated sweep point is used for all larger stimulus
values.
PCa<l|i|o|x> S
Like PCa<l|i|o|x>, but only a source flatness calibration is available
PCa<l|i|o|x> R
Like PCa<l|i|o|x>, but only a receiver calibration is available
PCal Off
The power calibration is no longer applied (e.g. deliberately turned off in the "Calibra-
tion > Use Cal " softtool panel).
Calibration
