Keysight Technologies N4374B, User Manual

Page: 77 / 164

Making Measurements
Keysight
N4374B Lightwave Component Analyzer, User’s Guide 75
Calibrating the Network Analyzer before Measurements
About measurements
Please refer to “Optimize a measurement” and “Calibrate a
measurement” in the documentation for the network analyzer.
• Always perform an electrical calibration of the network
analyzer or load an existing calibration set before making
measurements.
• Always make sure that, on the network analyzer, in the sweep
setup menu, that “Stepped sweep - sweep moves in discrete
steps” is selected.
• After completing the calibration, do not alter the test port
power, IF bandwidth, start frequency, stop frequency,
measurement point number or other settings.
You may get measurement errors if you change the
parameters.
Keep the following points in mind during network analyzer
electrical calibration.
• To get the best S/N ratio for your measurements, use highest
RF power your network analyzer can output without showing
a “source unlevelled” error. In many case this is more then
the maximum specified output power of the network
analyzer.
• Decreasing the IF bandwidth improves the S/N ratio of the
measurement. However, doing so increases the calibration
and measurement times, so a suitable IF bandwidth should
be selected.
• Apply appropriate averaging or smoothing for your
application.
Electrical calibration for single-ended measurements
To ensure the specified performance of the LCA, you need to
perform a full two-port electrical calibration using the
automated electronic calibration kit 85092C #00F or 85092C
#00A.
N O TE
When in EO, OE or OO measurement mode, you need to return to EE
measurement mode first before you can perform an electrical calibration