The Spectrum Application
FPC1000
59
User Manual 1178.4130.02 ─ 02
Defining the reference level
is the power level that the R&S
FPC1000 expects at the RF input.
When you select the reference level, make sure that you do not overload the
R&S
FPC1000 by applying a signal whose power exceeds the maximum reference
level.
As the power is measured with a small
bandwidth, it is still possible to overload the R&S
FPC1000, even if the trace is within
the measurement diagram. To prevent an overload, measure the occupied bandwidth
with the largest resolution bandwidth possible using the peak detector. If you set these
parameters, it is not possible for the trace to exceed the reference level.
To simplify operation and to prevent incorrect measurements, the R&S
FPC1000 has
an automatic routine for setting the reference level.
1. Press the "Meas" key to open the measurement menu.
2. Select the "Level Adjust" menu item.
The R&S
FPC1000 performs a measurement to determine the optimal reference
level.
It uses a resolution bandwidth of 1
MHz, a video bandwidth of 1
MHz and the peak
detector. After finishing the automatic measurement, the R&S
FPC1000 sets the
optimal reference level.
Changing the span
Usually, the span that the R&S
FPC1000 selects yields optimal results. But sometimes
you also need to see the spectrum outside the current span to detect other signal com-
ponents that you need to include in the measurement. Therefore, you can adjust the
span to up to ten times the channel bandwidth and hence still be able to see the spec-
trum outside the measurement channel.
1. Press the "Span" key to open the span menu.
2. Select the "Manual Span" menu item.
The R&S
FPC1000 opens an input field to define the span.
3. Enter the span you need.
Note:
The largest possible span for the channel power measurement is ten times
the channel bandwidth. At larger spans, the result of the channel power measure-
ment would be increasingly imprecise, because too few points of the trace would
be in the channel you are measuring.
9.2.2 Measuring the Occupied Bandwidth
Access
: "Meas" > "Measurement Mode" > "Occupied Bandwidth"
Remote commands to control the occupied bandwidth measurement:
●
Chapter 13.10.1, "Measurements and Result Displays"
Available with the optional "Advanced Measurements" application.
Measurements and Result Displays
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