System Crosstalk Test - Agilent Technologies E8362C Service Manual

Tests and Adjustments
Performance Tests (Agilent N7840A Software Package)

System Crosstalk Test

Function of the Test: To measure the level of signal leakage between the analyzer's test ports.
Specification Tested: Test Port Input–Crosstalk
Equipment Used: A calibration kit and a test cable.
Description of the Test:
1. The analyzer is tested in both directions at various frequency segments.
2. The analyzer sweep is set for the desired frequency and number of points at a 10 Hz IF bandwidth. The
power level is set to the lesser of either the maximum specified power level for the driving port or the
maximum input power level for the receiving port.
3. A test cable is connected between the driving and receiving ports.
4. The analyzer is set for a ratioed through measurement (S21 for example) with log magnitude display and
a sweep is taken and stored to memory (MEM).
5. The trace is set to data divided by memory (DATA/MEM).
6. The test cable is removed and shorts are placed on both ports.
7. The average of 16 sweeps is taken.
8. The resultant log magnitude trace represents the system crosstalk in dB for the frequency range or
segment tested.
If the Analyzer Fails this Test:
• A failure of this test usually indicates one of the following:
• a loose cable connection
• degradation of signal isolation in the receivers
• degradation of signal isolation on the A35 receiver motherboard
• Remove the covers from the analyzer and tighten all RF cable connections and tighten all screws on the
receivers and repeat this test. Refer to
Modules and A49 IF Multiplexer Board" on page 7-54
for illustrations of the cable and screw locations.
• If the analyzer still fails this test, replace the receiver associated with the port that is failing and repeat
this test. Refer to "Removing and Replacing the A31, A32, A33, and A34 Receiver Modules and A49 IF
Multiplexer Board" on page
• If the analyzer still fails this test, replace the A35 receiver motherboard and repeat this test. Refer to
"Removing and Replacing the A35 Receiver Motherboard" on page
3-36
"Removing and Replacing the A31, A32, A33, and A34 Receiver
7-54.
PNA Series Microwave Network Analyzers
for instructions on how to remove the covers and
7-56.
E8362C, E8363C, E836C
Service Guide E8364-90038