National Instruments NI PXIe-5673E, Процедура калибровки

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PXIe-5673E Calibration Procedure | © National Instruments | 19
9. Use the spectrum analyzer to measure the mean amplitude of the second close-in IMD tone
at 87.6 MHz (LO + 2
F
2
-
F
1
). Name this value
I
2
. Use the following spectrum analyzer
parameter settings:
•
Center frequency: (Frequency in step 4) +
F
2
• Reference level: 0 dBm
• Frequency span: 0 Hz
• Resolution bandwidth: 500 Hz
• Sweep time: 5 ms
• Reference clock source: External
10. Calculate output IMD using the following equation:
Output IMD
=
Large IMD tone power (I
1
or I
2
)
-
Small fundamental tone power (P
1
or P
2
)
11. Compare the
Output IMD
value from step 10 to the corresponding limit in Table 8.
12. Repeat steps 4 through 11 for the following frequency ranges in 250 MHz increments,
including endpoints:
•
PXIe-5650: 85 MHz to 1.3 GHz
• PXIe-5651: 85 MHz to 3.3 GHz
• PXIe-5652: 85 MHz to 6.6 GHz
Store the resulting measurements.
13. Repeat steps 4 through 11 with a power level of -30 dBm and a spectrum analyzer reference
level of -30 dBm.
Table 8. Intermodulation Products Verification Test Limits
with -6 dBm per Tone
CW Source LO Frequencies R3 Upper Limits (dBc)
PXIe-5650/5651/5652 85 MHz to 250 MHz -49
>250 MHz to 1.3 GHz -53
PXIe-5651/5652 >1.3 GHz to 3.3 GHz -48
PXIe-5652 >3.3 GHz to 6.6 GHz -47