Measurements and Result Displays
R&S
®
ESW
123
User Manual 1177.6298.02 ─ 08
Defining peak characteristics (or "When is a peak a peak?")
If a signal is, for example, very flat, contains a lot of noise or does not contain many
peaks, the R&S
ESW might miss potential peaks or detect peaks that really are no
peaks.
To avoid such situations, you can define what a peak is according to the following crite-
ria.
●
Peak excursion
The peak excursion is a relative threshold. The signal level must increase by the
threshold value before falling again before a peak is detected.
To avoid identifying noise peaks instead of a real signal peak, enter a peak excur-
sion that is higher than the difference between the highest and the lowest value
measured for the displayed inherent noise.
●
Limit lines
(not mandatory)
The signal level must be above the limit line (= fail the limit check) to be considered
as a peak.
●
Limit margin
(only if a limit line is active)
The level margin defines the distance relative to a limit line that a signal may at
most have so that it will be identified as a peak.
Figure 9-11: Peak definition
1 = Limit line
2 = Peak excursion
3 = Limit margin
Thus, a potential peak is written into the peak list under the following conditions.
Measurements without limit lines:
●
If a signal meets the condition defined by the peak excursion.
Measurements with limit lines:
●
If a signal level fails a limit check and meets the condition defined by the peak
excursion.
●
If a signal level passes a limit check, but is within the limit margin ("x dB below the
limit"), and still meets the peak excursion.
In the diagram, the peaks are labeled with a colored symbol. Color and type of symbol
depend on the trace the peak is on.
Test Automation
