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NI PXI-5663 Calibration Procedure
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© National Instruments
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13
13. Set the source to the center frequency shown in Table 4.
14. Adjust the RF source power so that:
Channel A Power
+
RF Calibration Factor
=
Reference Level
±1 dB
Reference Level
is the value from Table 3. Use the appropriate RF frequency for the channel
A sensor. Calculation of the
RF Calibration Factor
may require interpolation.
Note
Set the signal generator to its maximum power if it doesn’t have sufficient
power to reach the reference level.
15. Record the channel A power.
16. Set the NI 5663 to read the power spectrum using the niRFSA Read Power Spectrum VI or
the
niRFSA_ReadPowerSpectrumF64
function.
17. Get the spectrum information using the niRFSA Get Spectral Info for SMT VI or the
niRFSA_GetSpectralInfoForSMT
function.
18. Perform a peak search using the SMT Spectrum Peak Search VI. Set the peak threshold to
20 dB below the NI 5663 reference level.
19. Sort the peaks and record the maximum. Save this value as
RFSA Power
.
20. Calculate the
Absolute Accuracy
using the following formula:
Absolute Accuracy
=
RFSA Power
- (
Channel A Power
+
RF Input Calibration Factor
)
Calculation of the
RF Input Calibration Factor
may require interpolation.
21. Compare the
Absolute Accuracy
to the Verification Test Limits in Table 5.
22. Repeat steps 9 to 21 for all the settings in Tables 3 and 4.
23. Close the NI 5663 session using the niRFSA Close VI or the
niRFSA_close
function.
Table 5.
Absolute Accuracy Verification Test Limits
Frequency
As-Found Limit
As-Left Limit
10 MHz to <120 MHz
±2.20 dB
±1.70 dB
120 MHz to <400 MHz
±1.70 dB
±1.00 dB
400 MHz to <3.0 GHz
±1.60 dB
±0.97 dB
3.0 GHz to <5.5 GHz
±1.70 dB
±1.03 dB
5.5 GHz to 6.6 GHz
±1.60 dB
±0.93 dB