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National Instruments Corporation
19
NI PXIe-5611 Calibration Procedure
3.
Connect one available port of the power splitter to the power meter.
Caution
The port used to connect the power splitter to the 6 dB attenuator in step 9 of the
Characterizing the Power Splitter
section must be the same port used to connect the power
splitter to the power meter in step 4 of this section.
4.
Connect one available port of the power splitter to the 6 dB attenuator.
5.
Connect one available port of the 6 dB attenuator to the spectrum
analyzer RF INPUT front panel connector.
6.
Disconnect the NI 5450 CLK IN front panel connector from the
NI 5652 REF IN/OUT front panel connector.
7.
Generate a single-sideband tone with a +1 MHz offset from the carrier
with the following NI-RFSG property settings:
•
Frequency (Hz): 85 MHz
•
Power Level (dBm): 5 dBm
•
Generation Mode: Arb Waveform
•
Reference Clock Source: ClkIn
8.
Use the power meter to measure power splitter-compensated output
power.
9.
Repeat steps 7 through 8 for every frequency from 85 MHz to 6.6 GHz
in 20 MHz increments, including endpoints.
10. Set the NI-RFSG Power Level property to
0
dBm, and repeat steps 7
through 9.
11. Set the NI-RFSG Power Level property to
–30
dBm, and repeat steps 7
through 9, measuring the power using both the power meter and
spectrum analyzer. Use the following parameter settings for the
spectrum analyzer:
•
Center frequency: frequency in step 7 + 1 MHz
•
Reference level: –30 dBm
•
Frequency span: 0 Hz
•
Resolution bandwidth: 500 Hz
•
Sweep time: 20 ms
•
Reference clock source: External
•
Attenuation: 5 dB
•
Preamplifier: On
12. Use the power meter measurements to calculate a correction for the
spectrum analyzer inaccuracies and attenuator loss.