Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 372 / 813

Channel Menu R&S
®
ZVA/ZVB/ZVT
1145.1084.12 4.210 E-6
Calibration procedure
The source power calibration requires an external power meter, to be connected via GPIB bus, USB or
LAN interface. The power sensor can be connected directly at the reference plane or to any other point
in the test setup where the signal power is known to be proportional to the power at the reference
plane.
The source power calibration involves several steps:
5. The analyzer performs a first calibration sweep at the source power that is likely to
produce the target power ( Cal Power) at the reference plane. A known attenuation or gain at
the source port and in the signal path between the source port and the reference plane is taken
into account.
6. The power measured at the reference plane is displayed in the calibration sweep
diagram and compared to the Cal Power. The comparison serves as an input for the correction
of the source power.
7.
Steps 1 and 2 are repeated for a specified Number of Readings or after the deviation
between the measured power at the reference plane and the Cal Power is below a specified
Tolerance.
8. After the last calibration sweep, it is possible to perform an additional Verification
Sweep in order to check the accuracy.
After a power calibration one can expect the power at the reference plane to be within the range of
uncertainty of the power meter. After a change of the sweep points or sweep range, the analyzer
interpolates or extrapolates the calibration data.
The Source Power Cal dialog provides the following control elements:
•
Calibrate – Source contains all analyzer ports or external generators which can be used as a
source for the calibrated wave quantity. The list contains all analyzer ports Port 1 to Port n .
Generators (Gen 1, Gen 2, ...) must be configured explicitly in the System Configuration –