NI PXIe-5693 Calibration Procedure
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© National Instruments
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21. Measure the channel A power using the appropriate calibration factor for the power sensor
frequency.
22. Calculate the RF input tone 1 power using the following equation:
RF Input Tone 1 Power
=
Channel A Power
+
Sensor/20 dB Attenuator/Splitter Tracking
23. Turn off the RF source 1 output power.
24. Turn on the RF source 2 output power.
25. Set the RF source 2 power level to have a -5 dBm target tone power at the DUT input
connector using the following equation:
RF Source 2 Power Level = Target Tone Power +
RF Source 2 through Splitter and Combiner Path Loss
26. Measure the channel A power using the appropriate calibration factor for the power sensor
frequency.
27. Calculate the RF input tone 2 power using the following equation:
RF Input Tone 2 Power
=
Channel A Power
+
Sensor/20 dB Attenuator/Splitter Tracking
28. Adjust the RF source 2 power level until the difference between RF input tone 1 power and
RF input tone 2 power is less than 0.1 dB.
29. Turn on the RF source 1 output power.
30. Set the spectrum analyzer center frequency to the IMD fre 1.2 MHz.
31. Measure the spectrum analyzer peak amplitude. This value is the
Output IMD Power
.
32. Correct all spectrum analyzer readings using the
Cable and 10 dB Attenuator Loss
values
from steps 8 through 9 in the
Characterizing the Spectrum Analyzer (with Cable and 10 dB
section.
33. Read the NI 5693 downconverter gain value. This value is the
DUT Gain
.
34. Calculate the delta using the following equation:
Delta
=
RF Input Tone 1 Power - (Output IMD Power - DUT Gain)
35. Calculate the out-of-band TOI using the following equation:
Out-of-Band TOI = RF Input Tone 1 Power + (Delta/2)
36. Repeat steps 15 through 35 for all remaining frequencies in Table 10.
Note
For frequencies >700 MHz, use the high frequency power combiner in place
of the low frequency power combiner.
37. Repeat steps 15 through 36 for all frequencies in Table 10 with the NI 5693 preamp
enabled and the RF source 1 and RF source 2 power level set to -25 dBm. For steps 20
and 25, adjust the RF source target tone power to -25 dBm.
