R&S FSH
Spectrum Analyzer Mode
Configuring Spectrum Measurements
Operating Manual 1309.6275.12 - 14
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2.2.5.2 Selecting the Detector
The number of measurement results collected in a single sweep usually is very high,
especially if the span is large. However, the display of the R&S FSH can display only
631 results in horizontal direction, as it is limited by the number of pixels that are
available on the display. Therefore, it has to combine measurement results to fit them
on the display. In that case, one pixel represents a frequency range = span/631.
The detector determines the way the R&S FSH combines and displays the results for
one pixel. The data base is the video voltage of the analyzer.
The R&S FSH provides several types of detectors.
C
Auto Peak
If the auto peak detector is active, the R&S FSH displays both the maximum and
the minimum power levels that were measured in the frequency range covered by
a pixel.
Therefore, the auto peak detector loses no information. If a signal power level
fluctuates (e.g. noise), the width of the trace depends on the magnitude of the
signal fluctuation.
The auto peak detector is the default detector.
C
Max Peak
If the max peak detector is active, the R&S FSH displays only the maximum power
levels that were measured in the frequency range covered by a pixel.
The max peak detector is useful for measurements on pulse or FM signals, for
example.
C
Min Peak
If the max peak detector is active, the R&S FSH displays only the minimum power
level that were measured in the frequency range covered by a pixel.
The min peak detector displays sine signals with the correct level and suppresses
noise. Therefore it is useful to find sine signals in the vicinity of noise.
C
Sample
If the sample detector is active, the R&S FSH shows one random power level that
was measured in the frequency range covered by a pixel.
The sample detector is useful for measurements in the time domain (span = 0 Hz)
as it provides the only way to represent the timing of the video signal correctly.
In the frequency domain, the sample detector is a good way to measure noise
power because noise usually has a uniform spectrum with a normal amplitude
distribution.
Signals may get lost if you are using the sample detector for measurements with a
span that is greater than "RBW*631".
