Agilent Technologies N5242A Service Manual page 314

General Purpose Maintenance Procedures PNA Series Microwave Network Analyzers
Error Terms N5242A
Isolation (Crosstalk) (E and E )
XF XR
Isolation, or crosstalk, is the uncorrected forward and reverse isolation error terms that
represent leakage between the test ports and the signal paths. The isolation error terms
are characterized by measuring transmission (S , S ) with loads attached to both ports
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during the measurement calibration.isolation errors affect transmission measurements
primarily where the measured signal level is very low.
The measurements most affected by isolation error terms are DUTs with large insertion
loss. Since these terms are low in magnitude, they are usually noisy (not very repeatable).
Typical Cause of Failure A loose cable connection or leakage between components in the
test set are the most likely cause of isolation problems.
After verifying the cable and its connections, suspect the analyzer switch splitter, step
attenuator, coupler, or receivers, and associated cabling.
To troubleshoot, refer to "Checking the Receiver Group" on page 4-37 or to "Checking the
Signal Separation Group" on page 4-33.
8-12 Service Guide N5242-90001