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R&S ZVL
GUI Reference
Trace Menu
Operating Manual 1303.6580.32-06
139
It is possible to select, define and display up to ten different evaluation ranges for each setup.
Full Span
means that the search range is equal to the
sweep range.
The statistical and phase evaluation take into
account all measurement points with stimulus values x
i
between the
Start
and
Stop
value of the evaluation
range:
Start
x
i
Stop
The evaluation ranges are identical to the marker search ranges. For more information see Search
Range Dialog.
Remote control:
CALCulate<Chn>:STATistics:DOMain:USER <numeric_value>
CALCulate<Chn>:STATistics:DOMain:USER:STARt <numeric_value>
CALCulate<Chn>:STATistics:DOMain:USER:STOP <numeric_value>
Smoothing On
Activates the smoothing function for the active trace, which may be a data or a memory trace. With active
smoothing function, each measurement point is replaced by the arithmetic mean value of all measurement
points located in a symmetric interval centered on the stimulus value. The width of the smoothing interval
is referred to as the
Smoothing Aperture
and can be adjusted according to the properties of the trace.
The sweep average is an alternative method of compensating for random effects on the trace by
averaging consecutive traces. Compared to smoothing, the sweep average requires a longer
measurement time but does not have the drawback of averaging out quick variations of the measured
values.
Remote control:
CALCulate<Chn>:SMOothing[:STATe] <Boolean>
Smoothing Aperture
Defines how many measurement points are averaged to smooth the trace if smoothing is switched on.
The
Smoothing Aperture
is entered as a percentage of the total sweep span.
An aperture of n % means that the smoothing interval for each sweep point i with stimulus value x
i
is equal
to [x
i
– span*n/200, x
i
+ span*n/200], and that the result of i is replaced by the arithmetic mean value of all
measurement points in this interval. The average is calculated for every measurement point. Smoothing
does not significantly increase the measurement time.
Finding the appropriate aperture
A large smoothing aperture enhances the smoothing effect but may also average out quick variations of
the measured values and thus produce misleading results. To avoid errors, observe the following
recommendations.
•
Start with a small aperture and increase it only as long as you are certain that the trace is still
correctly reproduced.
•
As a general rule, the smoothing aperture should be small compared to the width of the observed
structures (e.g. the resonance peaks of a filter). If necessary, restrict the sweep range or switch
smoothing off to analyze narrow structures.
Remote control:
CALCulate<Chn>:SMOothing:APERture <numeric_value>