W9068A Datasheet, PDF (8/16 Pages) Keysight Technologies – Phase Noise X-Series

08 | Keysight | Phase Noise X-Series Measurement Application N9068A & W9068A - Technical Overview
Other measurement
features
Displayed average noise
level (DANL) measurements
The DANL floor of a signal/spectrum
analyzer sets limitations for measur-
ing the smallest input signal because
it may negatively affect phase noise
measurement accuracy at the far-
out offset frequencies. When the
amplitude of a signal under test gets
closer to the DANL floor, a signifi-
cant measurement error can occur,
invalid-ating the measurement. To
help ensure
the measurement is valid, the phase
noise measurement application mea-
sures the DANL floor noise
plot (Figure 5).
Figure 6. DANL measurement
The DANL measurement mode
allows you to:
–– Measure and reference the DANL
of the X-Series signal analyzer to
the carrier amplitude
–– Display the DANL floor together
with the log plot phase noise to
determine the valid measurement
range
–– Easily store and recall traces
Reference trace subtractions
By using the trace subtraction func-
tion, you can subtract the DANL floor
or phase noise of the X-Series signal
analyzer or MXE EMI receiver.
DANL subtraction
Subtract the signal analyzer's internal
broadband noise from the com-
pounded measurement result to see
the phase noise of the DUT at the
offset frequency where the noise
level of the signal analyzer and DUT
is close. Recall the stored DANL data
to subtract from measured data
(Figure 6).
Figure 7. Phase noise plot with subtraction of DANL; the DANL trace is in
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