Concepts and Features
R&S
®
ZNC
90
User Manual 1173.9557.02 ─ 13
Label
Meaning
PCao
The power calibration is applied, however, the source power (channel base power) was
changed.
PCax
The power calibration is applied, however the calibration data is extrapolated. The cur-
rent 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.
PCal Off
The power calibration is no longer applied (e.g. deliberately turned off in the "Calibration
> Use Cal " softtool panel).
A lower label in the list has priority over the higher labels (e.g. if the power calibration is
interpolated and the source power is changed, then the label PCao is displayed).
Interpolation and extrapolation
The analyzer can interpolate and extrapolate power correction data so that a source or
receiver power calibration can be reused after a change of the frequency sweep range:
●
At new sweep points within the calibrated sweep range, interpolation is applied to
calculate the correction data. A label "PCai" in the trace list indicates an interpolated
power calibration.
●
At new sweep points outside the calibrated sweep range, the correction values are
extrapolated: Sweep points below the lowest calibrated frequency are assigned the
correction value of the lowest frequency. Sweep points above the highest calibrated
frequency are assigned the correction value of the highest frequency. A label
"PCax" in the trace list indicates an extrapolated power calibration.
3.5.6.4
Extended Test Setups
The power calibration data can be modified to account for an additional two-port device
in the test setup. The known transmission coefficients of the two-port can be entered
manually or automatically ("CHANNEL > CAL > Pwr Cal Settings > Transm. Coeffi-
cients"). The R&S ZNC supports two different test scenarios.
A: Two-port at DUT (during measurement)
Calibration