NI PXIe-5611 Calibration Procedure
26
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Note
If the instrument specified is
Power Meter & Spectrum Analyzer
, then you
must measure the power with the power meter and the spectrum analyzer simultaneously.
These measurements are used to correct the spectrum analyzer’s inaccuracy.
11. Compensate only the power meter measurement for the loss of the
power splitter by subtracting the loss measured in the
section from the power meter measurement in
step 10 in this section.
12. Call the niRFSG 5611 Adjust RF Gain Calibration VI, and pass
the measurements from step 11 to the
Power Meter
Measurement (dBm)
and/or
Spectrum Analyzer Measurement
(dBm)
parameter.
13. When the spectrum analyzer measures a level of
≤
–110 dBm, increase
the sweep time for each measurement to 200 ms. The sweep time can
return to 20 ms when the
Measurement Instrument
parameter of the
niRFSG 5611 Configure RF Gain Calibration VI returns a value of
Power Meter
. The sweep time should alternate several times between
20 ms and 200 ms as these conditions are met.
Note
Only the instrument indicated by the
Measurement Instrument
parameter is
actually used. Values passed for the inactive instrument are ignored. The power meter is
used for higher power measurements, and the spectrum analyzer is used for lower power
measurements.
14. Repeat steps 8 through 12 until the
RF Gain Calibration Complete
parameter returns a value of TRUE. Additional averaging is required
on the spectrum analyzer to minimize the effects of noise at the lower
power levels. After a level of –90 dBm or less is measured, increase the
sweep time to 200 ms for the remaining measurements of the
procedure.
15. Call the niRFSG Close External Calibration VI to close the session and
store the results to the EEPROM on the NI 5611.
You have finished adjusting the NI 5611. Repeat the
section to
reverify the performance of the NI 5611 after adjustments.