National Instruments PXI-5650, Calibration Procedure

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NI PXI-5650/5651/5652 Calibration Procedure | © National Instruments | 7
2. Connect the PXI-5650/5651/5652 RF OUT front panel connector to the power meter
thermal sensor.
3. Call the niRFSG 5652 Get Calibration Frequencies.vi located in the
labview\
instr.lib\niRFSG\niRFSG5652Calibration\SubVIs
directory. In the
Calibration procedure
control, specify
Attenuators
, and in the
Model
control, specify
the device model name as
NI PXI-5650
,
NI PXI-5651
, or
NI PXI-5652
. A frequency
array is generated.
4. Build another frequency array for the appropriate device model using the frequencies listed
in Table 5,
Low-Level Accuracy Test Points and Limits ( ≤ -40 dBm) .
5. Concatenate the frequency arrays from step 3 and step 4. Pass the result into the niRFSG
Sort Array and Remove Duplicates (DBL).vi located in the
labview\instr.lib\
niRFSG\commonCalibration
directory. Record the resulting list of frequencies that is
generated.
6. Generate a signal at -35 dBm, and measure the power at all of the frequency test points
recorded in step 5.
7. Connect the rubidium 10 MHz frequency reference signal to the spectrum analyzer REF IN
rear panel connector.
8. Connect the 6 dB precision attenuator to the PXI-5650/5651/5652 RF OUT front panel
connector.
9. Connect the spectrum analyzer RF INPUT connector to the 6 dB precision attenuator.
10. Generate a single-tone signal after setting the following NI-RFSG property settings:
• Frequency (Hz): 500 kHz
• Power Level (dBm): -35 dBm
• Generation Mode: CW
• Reference Clock source: RefIn
11. Use the spectrum analyzer to measure the mean power of the RF output using the following
spectrum analyzer settings:
•
Frequency: NI-RFSG frequency (Hz) value obtained in step 10
• Reference level: -38 dBm
• Resolution bandwidth: 30 Hz
• Frequency span: 0 Hz
• Reference Clock source: External
• Trace averaging: 20 averages
12. Repeat step 11 for each of the frequencies in the array that you recorded in step 5.
13. Calculate the
Spectrum Analyzer Correction Factor by subtracting each measurement in
step 11 from the corresponding measurement in step 6 at the same frequency. Record the
result.
Tip
The numbers will be positive if the subtraction is performed correctly.