Keysight Technologies N9330B, Руководство пользователя

Страница: 31 / 107

Making Measurements
Calibrate the N9330B before making measurements
25
Calibrate the N9330B before making
measurements
Before making a measurement (SWR/Return loss/Cable
loss/DTF) in a specified frequency range or the full span,
you must calibrate your N9330B.
It is important to keep the calibration frequency range as
close as possible to the actual sweep frequencies
necessary for the measurements. Calibrating over a
larger frequency range than the actual measurement
range will reduce the accuracy of the test results. For
example, using a 1 GHz calibration range when the
measurement range is only few kHz.
Performing one calibration is acceptable provided the
calibration frequency range selected incorporates all
intended measurement frequencies. If the frequency
span is changed, a new calibration must be performed
for that measurement. A new calibration must be
performed if any components used in the calibration
setup are changed. For example, a short coaxial cable
used to connect the tester to the DUT.
Calibration Mode
The N9330B offers two calibration modes:
•
FullSpan Cal

Runs an open-short-load calibration across the full
frequency span (25 MHz to 4 GHz). 
A FullSpan Cal ignores the frequency changes during
measurements.
•
SelectedSpan Cal

Performs an open-short-load calibration across a
user-defined frequency span. A SelectedSpan Cal
requires a re-calibration of the tester, after changing
the measurement frequency range. Normally, the
selected span should be set as close to the actual
swept frequency range.
Key access:
[SYS] > {Cal Mode}