Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 377 / 813

R&S
®
ZVA/ZVB/ZVT Channel Menu
1145.1084.12 4.215 E-6
Generators (Gen 1, Gen 2, ...) must be configured explicitly in the System Configuration –
External Generators dialog before they appear in the list. Behind the source, a message
indicates the status of the power calibration.
•
Take Cal Sweep initiates a calibration sweep for the selected wave quantity and source. The
progress of the sweep is monitored in the Sweep progress bar.
•
Abort Sweep stops a running sweep. The data acquired in the aborted sweep is discarded.
The accuracy of the receiver power calibration depends on the accuracy of the source.
Depending on the test setup and reference plane, it is recommendable to perform a source
power calibration before the receiver power calibration.
Remote control: [SENSe<Ch>:]CORRection:POWer:ACQuire
[SENSe<Ch>:]CORRection:POWer:AWAVe[:STATe]
[SENSe<Ch>:]CORRection:POWer:DATA
[SENSe<Ch>:]CORRection:POWer[:STATe]
Status Messages for Power Calibration
The status of a power calibration is indicated in the trace list and in the Used Source panel of the
Receiver Power Cal dialog. The following messages can be displayed:
•
PCal denotes an active power calibration with unchanged sweep points (no interpolation or
extrapolation).
•
PCai denotes an active, interpolated power calibration (at least one calibration step is
interpolated).
•
PCa? denotes an active power calibration with changed step attenuator setting and disabled
ALC.
•
PCao denotes an active power calibration with a changed source power (in at least one
calibration step).
•
PCax denotes an active, extrapolated power calibration (in at least one calibration step).
•
Uncal denotes an uncalibrated source (not available for traces).
The labels appear in the trace list, provided that the measured quantity is an S-Parameter, wave
quantity, ratio, or a derived quantity (stability factor, PAE), and that the necessary calibrations have
been performed.
Necessary Calibrations
A trace is marked as power calibrated as soon as the analyzer assumes that the effects of an
inaccurate source or receiver power have been consistently removed. The conditions for consistency
depend on the measured quantity (see also
Data Flow) :
•
S-parameters S
xy
represent the ratio of a received wave b
x
to a driving wave a
y
. The system
error correction for S-parameters generally includes a receiver power calibration, however, a
source power calibration can still improve the accuracy. Therefore S-parameters are assumed
to be power calibrated as soon as the driving wave has been power calibrated. The same holds
for quantities derived from S-parameters, e.g. stability factors.
•
For wave quantities, ratios, and derived quantities (e.g. the PAE), the driving waves and all
receivers must be power calibrated.