18 N9069C Noise Figure Measurement Guide
Making Noise Figure Measurements
Making Basic Measurements
If any input frequencies are in high band, that is above 3.6 GHz, the
Calibrate process will optimize the preselector at these frequencies and
use these preselector adjust values in the calibration acquisition results
and when acquiring the measurement results. This reduces the error
corrected results since the preselector is set at the same place for
acquiring the calibration and measurement results. The Optimize
Preselector function (
Meas Setup
,
Optimize Preselector
) allows the
adjusted values to be collected again without the calibration acquisition
results.
If you do not have either a High Band Preamp, or an external preamp and
you are calibrating above 3.6 GHz, the calibration data will vary
significantly. Measurements made with this calibration data might be
valid, but only if the device you are testing has a high gain. If this is not the
case, the measurement accuracy will be poor.
When using external preamplifiers or high-gain DUTs, ensure that neither
the external preamp (or the high-gain DUT) nor the internal preamp go into
compression as this will affect the accuracy of your measurements. If you
suspect that one or another of the preamplifiers is going into compression,
use attenuation prior to that preamplifier to prevent compression. The
analyzer’s internal attenuator will only affect compression occurring in the
internal preamplifier. It will not have any effect on any compression
occurring in the external preamplifier.
Step
Action
Notes
Summary of Contents for CXA N9000B
Page 4: ...4...
Page 8: ...8 Contents...
