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NI PXIe-5601 Calibration Procedure
25. Set the RF source power using the value from Table 30 for the RF attenuation index being
used.
26. Configure the NI PXI/PXIe-5652 frequency to the LO start frequency shown in Table 20
using the niRFSG Frequency property or the
NIRFSG_ATTR_FREQUENCY
attribute.
27. Wait 750 ms or until power sensor A settles to 0.1% of source power, whichever is greater.
28. Measure the
Channel A Power
. Calculate
RF Power
using the following equation:
RF Power
=
Channel A Power
+
RF Input Calibration Factor
Use the appropriate RF frequency for the channel A sensor. Calculation of the
RF Input
Calibration Factor
may require linear interpolation.
29. Measure and record the
IF Power
using power sensor B. Use the appropriate
IF Frequency
from Table 20.
30. Calculate
Gain
using the following formula:
Gain
=
IF Power
-
RF Power
31. Store the appropriate calibration constants using the
niRFSA Cal Adjust Reference Level Calibration VI or the
niRFSA_CalAdjustRefLevelCalibration
function. Set the following parameters:
•
ref level cal data type
—If
Mechanical Attenuator
from Table 20 is Enabled,
set to
Default
(or
NIRFSA_VAL_DEFAULT
). Otherwise,
set to
Mechanical Attenuator Disabled
(or
NIRFSA_VAL_EXT_CAL_MECHANICAL_ATTENUATOR_DISABLED
).
•
RF band
—Refer to Table 20.
•
attenuator table number
—1.
•
frequency
—Set to the corresponding frequency from step 15.
•
gain
—Computed in step 30.
32. Increment the RF start frequency and the LO start frequency by the specified
Step Size
from
Table 20. Repeat steps 14 to 31 for each RF frequency starting with 120 MHz up to and
including 6.6 GHz.
Note
Be sure to include the start and stop frequencies for each row before moving
to the next row in the table. This set of iterations should include rows 1 through 8 of
Table 20.
33. Repeat steps 14 to 32 for each
RF Attenuation Index
shown for the first eight rows of
Table 20.
Note
NI recommends keeping your RF signal generator enabled when repeating
steps unless making a connection change. Keeping the signal generator enabled
reduces the wear on the RF signal generator relays. After making a connection
change and enabling your generator, wait 5 seconds for the system to settle.
