Rohde & Schwarz ESW Series, User Manual

Page: 230 / 759

Common Analysis and Display Functions
R&S
®
ESW
230 User Manual 1177.6298.02 ─ 08
Marker # Min. amplitude decrease to either side of the signal
1 30 dB
2 29.85 dB
3 20 dB
4 10 dB
5 18 dB
In order to eliminate the smaller peaks M3,M4 and M5 in the example above, a peak
excursion of at least 20 dB is required. In this case, the amplitude must rise at least 20
dB before falling again before a peak is detected.
Marker peak list
The marker peak list determines the frequencies and levels of peaks in the spectrum. It
is updated automatically after each measurement. How many peaks are displayed can
be defined, as well as the sort order. In addition, the detected peaks can be indicated
in the diagram. The peak list can also be exported to a file for analysis in an external
application.
Automatic peak search
A peak search can be repeated automatically after each measurement in order to keep
the maximum value as the reference point for a phase noise measurement. This is
useful to track a drifting source. The delta marker 2, which shows the phase noise
measurement result, keeps the delta frequency value. Therefore the phase noise mea-
surement leads to reliable results in a certain offset although the source is drifting.
In the Receiver application, the R&S ESW provides an automatic peak search. In that
case, the R&S ESW searches for peaks when a scan is over. The search results are
added to the marker peak list as usual and are the basis for the final measurement. For
more information, see
Chapter 9.3.4, "Performing a Peak Search" , on page 122.
Using a peak as a fixed reference marker
Some results are analyzed in relation to a peak value, for example a carrier frequency
level. In this case, the maximum level can be determined by an initial peak search and
then be used as a reference point for further measurement results.
11.4.2 Marker Settings
Access : "Overview" > "Analysis" > "Marker"
The remote commands required to define these settings are described in Chap-
ter 15.7.4, "Markers" , on page 537.
● Individual Marker Setup ........................................................................................ 231
● General Marker Settings ....................................................................................... 233
Marker Usage