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PXIe-5665 Calibration Procedure
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© National Instruments
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37
4.
Set the PXIe-5665 center frequency according to Table 16.
5.
Set the PXIe-5665 channel coupling, RF attenuation, device instantaneous bandwidth,
span, resolution bandwidth, sampling ratio, and number of averages according to Table 17.
6.
Commit the PXIe-5665 settings to hardware.
7.
Read the power spectrum from the PXIe-5665. Convert the power spectrum to a power
spectral density (dBm/Hz) value.
8.
Remove five points from around the center of the power spectral density from step 7.
9.
Convert the power spectral density with the points removed to watts/Hz, take the mean, and
then convert the result back to dBm/Hz. This value is the
PXIe-5665 Average Noise
(dBm/Hz)
.
10. Repeat steps 4 to 9 for all frequencies in Table 16.
11. Repeat steps 4 to 10 for frequencies less than or equal to 3.6 GHz with the PXIe-5665
preamplifier enabled.
12.
(PXIe-5665 14 GHz VSA)
Repeat steps 4 to 10 for frequencies greater than 3.6 GHz with
the PXIe-5665 preselector enabled and preamplifier disabled.
Note
The PXIe-5665 preselector has a maximum instantaneous bandwidth of
47 MHz. For steps that call for a 50 MHz instantaneous bandwidth, use a 40 MHz
instantaneous bandwidth when using the preselector.
Table 16.
Average Noise Level Verification Test Frequencies
Start Frequency
Stop Frequency
Step Size (MHz)
10 MHz
90 MHz
20
100 MHz
3.6 GHz
500
4 GHz
14 GHz
500
Table 17.
PXIe-5665 Settings for Average Noise Level Verification
Test Frequency
Device Instantaneous
Bandwidth
Span
OSP Sampling
Ratio
10 MHz to <100 MHz
300 kHz
100 kHz
32
100 MHz to
≤
3.6 GHz
300 kHz
100 kHz
32
50 MHz
*
5 MHz
1
3.8 GHz to 14 GHz
50 MHz
*
5 MHz
1
*
Set the PXIe-5665 Device Instantaneous Bandwidth to 25 MHz for the PXIe-5665 with
25 MHz bandwidth.