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NI PXIe-5601 Calibration Procedure
d.
Calculate the
NI 5601 Calculated Gain
at each RF frequency using the following
formula:
NI 5601 Calculated Gain
=
Channel B Power
(or
Corrected Spectrum Analyzer Power
) -
(
Channel A Power
+
RF Input Attenuated Calibration Factor
)
Use the same
RF Input Attenuated Calibration Factor
that you used in Step 13a.
14. Recall the
NI 5601 Stored Gain
for each test frequency using the niRFSA Downconverter
Gain property or the
NIRFSA_ATTR_DOWNCONVERTER_GAIN
attribute.
15. Calculate the
Absolute Gain Accuracy
using the following formula:
Absolute Gain Accuracy
=
NI 5601 Calculated Gain
-
NI 5601 Stored Gain
16. Compare the
Absolute Gain Accuracy
to the
Verification Test Limits
in Tables 6 or 7, as
appropriate.
17. Repeat steps 8 to 16 for all the settings in Tables 2 and 3.
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.
18. Close the NI 5601 session using the niRFSA Close VI or the
niRFSA_close
function.
Reference Levels Greater than or Equal to -30 dBm
1.
Connect the RF source to the power splitter input through the 3.5 mm-to-3.5 mm cable.
2.
Connect the power splitter reference output to power sensor A.
3.
Connect the other power splitter output to the NI 5601 RF IN connector through the
3.5 mm-to-3.5 mm adapter.
4.
Ensure that the 50
Ω
terminator that shipped with the NI 5601 is connected to the NI 5601
LO OUT connector.
5.
Connect the NI 5601 IF OUT connector to power sensor B or to the spectrum analyzer
input. To choose which connection to make, refer to the following conditions:
•
Use the spectrum analyzer with the 3.5 mm-to-3.5 mm cable for RF frequencies
≤
120 MHz.
•
Use power sensor B with the SMA (m)-to-SMA (f) right angle adapter for
RF frequencies
≥
120 MHz.
Figure 4 shows the completed equipment setup.
6.
Create a new session for the NI 5601 using the niRFSA Initialize With Options VI or the
niRFSA_initWithOptions
function. Set the Driver Setup portion of the
option string
parameter to
DriverSetup=Digitizer:<external>
.
7.
Lock the NI PXI/PXIe-5652 to the Reference Clock used by the external test equipment.
Use the niRFSA Configure Ref Clock VI or the
niRFSA_ConfigureRefClock
function.
