R&S ZVB - Page 382

R&S
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ZVA / R&S
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ZVB / R&S
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ZVT GUI Reference
Channel Menu
Operating Manual 1145.1084.12 – 30 367
5. Noise Figure Calibration opens the Noise Figure Calibration dialog to assess and compensate the
internal noise at the NWA receiver and source.
6. S-Parameter Calibration opens the Calibration wizard for the previously selected input and output ports
and the Cal Method. If this step is skipped, the previous power and noise figure calibrations effectively
ensure a transmission normalization; the noise figure trace line contains no calibration state label (except
Pcal or another power calibration state label). With an additional One Path Two Port or Full Two Port
calibration, the system error correction of the gain G
D
(and thus the noise figure measurement in total) is
improved. The trace lines for the calibrated ports indicate Cal; the noise figure trace is labeled Cal NCal
(see Noise Figure Calibration State Labels). A Full Two Port calibration requires more calibration
measurements but provides best accuracy; see section Calibration Types.
Port <n> Pwr Offset is enabled if Preamp or Direct Receiver Access Used is checked in the Receiver
Power Calibration panel. <n> is the DUT output port number. The power offset increases or decreases the
source power at port <n> during the calibration. If a generator step attenuator is available at port <n>, it
also selects the Low Noise step attenuator mode. If a pre-amplifier is used in the receiver path, a power
reduction (negative value of the Port <n> Pwr Offset) may be required to prevent excess power levels at
the input of the pre-amplifier or at the NWA receiver port during the calibration.
Note: An S-parameter calibration is required for S-parameter measurements in parallel to the noise figure
measurement. The large IF bandwidth required for noise figure measurements limits the accuracy of the
calibration and the subsequent S-parameter measurements; the AVG detector can improve the results.
7. Configure Traces provides a selection of traces which are commonly of interest for the noise figure
measurement. The selected traces are created and displayed when the Replace or Add buttons are
clicked. Moreover, the DUT input port (e.g. P 1) appears in front of the power values in the channel line
The noise figure trace (NF21) is smoothed automatically (label SMO in the trace line). The large IF
bandwidth limits the accuracy of the S-parameter measurement; the AVG detector can improve the
results. Use the Trace – Measure menu if you wish to modify the trace settings.
To avoid misleading results, S-parameter selection is enabled only after an S-Parameter Calibration has
been performed.
Mixer Noise Figure Setup Guide
The Noise Figure Setup Guide for mixers is similar to the setup guide for noise figure measurements on
non-frequency converting DUTs described above. The basic steps will be outlined in the following.