8
|
ni.com
|
PXIe-5673 Calibration Procedure
13. Subtract the power measurements from step 12 from the measurements in step 5 for each
corresponding frequency, as shown in the equation below. Store the resulting calculations
as
splitter loss [i]
(dB). The result is an array representing the loss through the splitter for
the entire needed frequency range in 5 MHz increments.
splitter loss [i]
(dB) =
direct [i]
-
splitter [i]
Note
This array is later used to compensate measurements and correct for splitter
loss. If you do not find the exact frequency needed in the splitter correction array, use
the loss corresponding to the next closest frequency.
You have successfully characterized your splitter.
As-Found and As-Left Limits
The as-found limits are the published specifications for the PXIe-5673. NI uses these limits to
determine whether the PXIe-5673 meets the device specifications when it is received for
calibration.
The as-left limits are equal to the published NI specifications for the PXIe-5673 less guard bands
for measurement uncertainty, temperature drift, and drift over time. NI uses these limits to
determine whether the PXIe-5673 meets the device specifications over its calibration interval.
Verification
This section describes the steps you must follow to verify the published specifications for the
PXIe-5673.
Verification tests the following PXIe-5673 specifications:
•
LO output power accuracy
•
Modulation impairments
•
Modulation bandwidth and impairments
•
Output power level accuracy
•
Intermodulation products
•
Noise floor
•
RF harmonics
•
Baseband linearity-related spurs
•
Phase noise
•
Frequency accuracy
Note
Ensure that the PXIe-5611, PXIe-5450, and PXI-5650/5651/5652 are
properly connected and associated in MAX, as indicated in the
NI RF Signal
Generators Getting Started Guide,
before starting verification.
