Specifications

2. Check DUT mating connector(s) condition and pin depth.
3. Measure an alternate known good DUT, if possible.
4. Check if the environment is stable enough for the accuracy required
for the DUT measurement.
5. Check that the system has not been subjected to
greater-than-specification variations in temperature.
6. Check that the system has not been placed in direct sun light or
next to a changing cooling source, such as a fan or air conditioning
unit.
7. Check the calibration using known good components from the cali
-
bration kit. If measurements of these devices do not produce good re
-
sults, perform Steps 8 and 9.
8. Check the throughline cable stability, including condition and pin
depth. Replace with a known good cable, if necessary.
9. Check the condition and pin depth of the calibration kit components.
Replace them with known good components, if necessary.
10. Check the system performance as follows:
q
Perform the Signal Path Tests that are part of the Operational
Test.
q
Perform the Performance Verification Test.
6-7 NOISE FIGURE
MEASUREMENT
PROBLEM
This section describes some commonly encountered noise figure measure
-
ment problems and their solutions.
Problem The NOT ALLOWED error message is displayed when selecting NOISE
FIGURE WITH 12 TERM under the PERFORM CAL menu:
Solution Perform a new 12-term S-parameter calibration between 50 MHz and
6 GHz (50 MHz and 3 GHz with Option 4).
Noise Figure is only available between 50 MHz and 6 GHz. S-parameter
calibrations outside this frequency range generates the NOT ALLOWED
error message.
Problem Negative Noise Figure:
Solution Use the same Source Power setting in both the Transmission/Reflection
and Noise Figure setup.
6-24 MS462XX MM
NOISE FIGURE MEASUREMENT PROBLEM TROUBLESHOOTING