Service Guide E8361-90001 A-15
PNA Series Microwave Network Analyzers Error Terms
E8361A Error Term Data
Isolation (E
XF
and E
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
21
, S
12
) with loads attached to both ports
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 4-52 or to “Checking the
Signal Separation Group” on page 4-49.
Figure A-8 Typical E
XF
/E
XR
with 10 Hz Bandwidth