Receiver Mode
R&S
®
ESR
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be switched to interactive. Measurement settings can not be changed. The advantage
is that the measurement runs on its own.
Control of the final measurement is possible in interactive final measurement mode.
In interactive final measurement mode, the R&S
ESR stops on each frequency of the
peak list. If required, the frequency can be fine tuned, e.g. if the interferer has shifted.
For fine tuning, the bargraph display can be used to find the new peak value. The level
measurement is performed only after initialization by the user.
It is possible to start with an automatic measurement and later change into interactive
mode. Likewise, it is possible to start measuring in interactive mode and later change
into automatic mode.
5.1.6
Spectrogram
In receiver mode, the R&S
ESR provides a spectrogram result display for scans and
for IF analysis. For both result displays, the spectrogram allows you to view and evalu-
ate the signal characteristics over time.
5.1.6.1
How a Spectrogram Works
A spectrogram shows the spectral density of a signal in the frequency domain and over
time simultaneously. It provides an overview of the spectrum over time and so allows
for an easy detection of anomalies and interfering signals.
The horizontal axis represents the frequency span. The vertical axis represents time.
Time in the spectrogram runs chronologically from top to bottom. Therefore, the top of
the diagram is the most recently recorded data. A spectrogram also shows the power
levels that have been measured. To display the level information, the R&S
ESR maps
different colors to each power level that has been measured.
Creating a spectrogram consists of several stages.
●
Data acquisition based on the scan or the IF analysis
●
Result coloring
●
Data processing
The stages occur simultaneously.
Data acquisition
The spectrogram uses the traces of the scan or the IF analysis as its data basis. The
data capture process is therefore the same as that of these two measurements.
Note that if you use the Scan or IF Analysis result displays, the R&S
ESR saves spec-
trogram data even if the spectrogram result display is off.
After the data has been captured, the R&S
ESR transforms the data of the traces into
the spectrogram result display.
Measurements and Result Displays
