© National Instruments Corporation 19 NI PXI-5600 Calibration Procedure
6. Loop 121 times. Include the following steps in each loop:
a. Call
niTuner_CalGetStepFrequency with the following
inputs:
• startFrequency =
88 MHz (in terms of Hz)
• stopFrequency =
112 MHz (in terms of Hz)
• numberOf Steps =
121
• index = current index of the loop (first iteration is 0)
The return value is the frequency of the current loop iteration.
b. Set the signal generator frequency to the frequency (in Hz)
returned by
niTuner_CalGetStepFrequency in step 6a.
c. Set channel A on the power meter to the frequency returned in
step 6a minus 85 MHz.
d. Set channel B on the power meter to the frequency returned in
step 6a.
Note Refer to your power meter user documentation for instructions on setting the
frequency.
e. Wait 200 ms for the signal generator and the power meter to settle.
f. Acquire channels A and B on the power meter. Send them as
inputs to
niTuner_CalAdjustExternalCalibration with
the following values:
• IFOutputPower = channel A power (in dBm)
• RFInputPower = channel B power (in dBm)
• calibrationProcedure =
1 (IF frequency response
adjustment)
Table 7. IF Adjustment Settings
Calibration
Iteration
Signal
Generator
Amplitude
NI PXI-5600
Parameters
Reference
Level
Mixer
Level
1 –14 dBm –20 dBm –30 dBm
2 –4 dBm –10 dBm –20 dBm
3 6 dBm 0 dBm –10 dBm
4 6 dBm 10 dBm 0 dBm
