Measurements and Result Displays
R&S
®
ESW
109
User Manual 1177.6298.02 ─ 08
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Generating subrange maxima (search method "Subranges").
The whole frequency range is divided into equidistant frequency subranges. A
selectable number of subrange maxima are determined for each subrange. In the
final measurement, the interference spectrum is further analyzed at frequencies
with the highest interference level of a frequency subrange.
1 = Subrange
2 = Subrange maximum
3 = Limit line
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Determination of a specific number of peak values relative to the limit lines with the
level values being independent of their frequency spectral distribution (search
method "Peaks").
Determining the level maxima irrespective of their distribution in the frequency
spectrum is suitable for measurement regulations that demand determination of the
relatively highest level irrespective of the distribution in the measured frequency
range, e.g. FCC.
If the prescan is performed in parallel with several detectors, typically Peak and Aver-
age, the maxima are determined separately for the two detectors so that the distribu-
tion of narrowband and wideband sources of interference can be taken into account.
For example, the frequency of the maximum determined with the average detector can
be used for the final measurement performed with the CISPR Avg detector and the fre-
quency found in the prescan carried out with the peak detector is taken for the final
measurement using the quasipeak detector.
Consideration of the limit lines ensures that the final measurement is not performed at
frequencies at which the inference level is far below the limit value. A margin below the
limit line can be defined (in dB). Peak values measured in the margin area are also
considered in the final measurement. The margin is valid for all limit lines. Each limit
line is allocated to a trace, i.e. different limit lines are taken for the different detectors.
If no limit lines are activated, the measurement procedure is as if all measured values
would exceed the limit line.
Data Reduction by Editing the Peak List
As an alternative method, it is possible to preset a list of frequencies at which the final
measurements are performed. A typical application is, for example, the statistical
analysis of several units.
Test Automation
