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Measurement Basics
R&S
®
FSW-K40
26
User Manual 1173.9286.02 ─ 15
1. Half decade averaging.
The application measures each half decade a particular number of times before
measuring the next one.
2. Cross-correlation
The application performs a certain number of cross-correlation operations in each
half decade.
3. Sweep Count.
The application measures the complete measurement range a particular number of
times.
It again includes half decade averaging as defined.
After the measurement over the sweep count is finished, the application displays
the averaged results.
4. Trace smoothing.
Calculates the moving average for the current trace.
4.5.1 Half Decade Averaging
Define the number of measurements that the application performs for each half decade
before it displays the averaged results and measures the next half decade.
In combination with the RBW, this is the main factor that has an effect on the measure-
ment time. Typically you will use a small number of averages for small RBWs because
small RBWs already provide accurate results and a high number of averages for high
RBWs to get more balanced results.
4.5.2 Sweep Count
The sweep count defines the number of sweeps that the application performs during a
complete measurements.
A sweep in this context is the measurement over the complete measurement range
once. A complete measurement, however, can consist of more than one sweep. In that
case the application measures until the number of sweeps that have been defined are
done. The measurement configuration stays the same all the time.
In combination with the Average trace mode and half decade averaging, the sweep
count averages the trace even more.
4.5.3 Trace Smoothing
(Software-based)
smoothing
is a way to visually remove anomalies in the trace that
may distort the results. The smoothing process is based on a moving average over the
complete measurement range. The number of samples included in the averaging proc-
ess (the
aperture
size) is variable and is a percentage of all samples that the trace con-
sists of.
Trace Averaging