Rohde & Schwarz FPC1000, User Manual

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The Spectrum Application
FPC1000
89
User Manual 1178.4130.02 ─ 02
9.6.1 Sweep Time
The sweep time (or measurement time) is the time that the analyzer requires to acquire
and analyze the data in the selected frequency span . Large spans require more time to
measure than small spans. Generally, the R&S FPC1000 requires at least 20 ms for
every 600 MHz of span.
In addition to the frequency span, the measurement time also depends on the selected
resolution bandwidth : smaller resolution bandwidths require more time to settle than
large ones. If the measurement time is too short, the resolution filter has no time to set-
tle. In that case, the displayed levels will be too low.
In its default state, the R&S
FPC1000 automatically selects a measurement time that
makes sure that the measurement results for the selected span and resolution band-
width are correct and valid. If you change span or resolution bandwidth, the
R&S FPC1000 adjusts the measurement time accordingly.
In the time domain (span = 0), the R&S FPC1000 shows the video voltage over time.
The horizontal axis becomes a time axis that starts at 0 s and ends at the measure-
ment time that you have selected.
Defining the sweep time
1. Press the "Sweep" key to open the sweep menu.
2. Select one of the "Sweeptime: <x>" menu items.
● "Sweeptime: Manual"
Opens an input field to define the measurement time.
A manually selected measurement time is indicated by a blue dot in front of the
"SWT" label in the status bar.
Figure 9-12: Indicator of a manual sweep time
● "Sweeptime: Auto"
Automatically selects an appropriate measurement time depending on the cur-
rent
frequency span and resolution bandwidth .
Tip:
When you press the "Sweep" key, the R&S FPC1000 automatically opens an
input field to define the sweep time. If the input field is inactive, you can open it with
the "Sweeptime: Manual" menu item.
9.6.2 Sweep Mode
The sweep mode defines how often the analyzer measures the frequency spectrum.
In continuous mode, the R&S
FPC1000 repeats the measurement of the selected span
over and over until you stop it deliberately. The measurement results are updated
accordingly.
In single sweep mode, the R&S
FPC1000 measures the frequency spectrum once and
then stops without updating the results any longer. Another measurement starts only
when you deliberately initiate it. Note that in case of the average trace mode , a single
Sweep Configuration
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