R&S FSL Setting Traces – TRACE Key
1300.2519.12 4.41 E-11
This mode is not available for statistics measurements or if the TV trigger is active and the TV Free
Run On/Off softkey is set to ON (option TV Trigger, B6).
• Average
The average is formed over several sweeps. All available detectors can be selected. If the detector
is automatically selected, the sample detector is used. For details see also "Description of the
averaging method" on page 4.41.
This mode is not available for statistics measurements or if the TV trigger is active and the TV Free
Run On/Off softkey is set to ON (option TV Trigger, B6).
• View
The current contents of the trace memory is frozen and displayed.
If a trace is frozen, the instrument settings, apart from level range and reference level (see below),
can be changed without impact on the displayed trace. The fact that the trace and the current
instrument setting do not correspond any more is indicated by the enhancement label "*" at the left
edge of the grid.
If level range or reference level are changed, the R&S FSL automatically adapts the measured data
to the changed display range. This allows an amplitude zoom to be made after the measurement in
order to show details of the trace.
• Blank
Hides the selected trace.
Description of the averaging method
Averaging is carried out over the measurement points derived from the measurement samples. Several
measured values may be combined in a measurement point. This means that with linear level display
the average is formed over linear amplitude values. The sweep mode (continuous or single sweep, for
details see "Configuring the Sweep Mode – SWEEP Key" on page 4.24) and running averaging apply to
the average display analogously. In principle, two methods for calculating the average are used:
continuous averaging and averaging over the selected number of sweeps.
• sweep count > 1
Depending on the relation of the following two parameters, two different situations exist:
n = number of sweeps performed since measurement start
c = sweep count (number of sweeps forming one statistics cycle)
– n
c
In single sweep or continuous sweep mode during the first statistics cycle, averaging over the
selected number of sweeps is performed. The average trace n is calculated at each
measurement point according to:
)(
1
)1(
1
)( nCurr
nAvg
n
nAvg +
= Equ. 4–1
with Avg = average trace; Curr = current trace
Until the first statistics cycle is completed (n < c), a preliminary average is displayed which
represents the arithmetic mean value over all measured sweeps. With n increasing, the
displayed trace is increasingly smoothed since there are more single sweeps for averaging.
When the first statistics cycle is completed (n = c), the average trace is saved in the trace
memory.
– n > c
To Next Page
Loading...
