The Spectrum Application
R&S
®
FPC
73
User Manual 1178.4130.02 ─ 07
The R&S
FPC opens a dialog box to select the standard.
3. Select one of the available standards.
The R&S
FPC loads the configuration of the selected standard. It automatically
sets the span, resolution bandwidth, video bandwidth, sweep time and detector
required by the standard.
If the measurement is not according to the selected standard anymore (for exam-
ple if you change a parameter), the R&S
FPC shows a blue dot in front of the stan-
dard display.
Defining the reference level
is the power level that the R&S
FPC expects at the RF input. When
you select the reference level, make sure that you do not overload the R&S
FPC 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
FPC, 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
FPC 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
FPC 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
FPC sets the optimal
reference level.
Changing the span
Usually, the span that the R&S
FPC selects yields optimal results. But sometimes you
also need to see the spectrum outside the current span to detect other signal compo-
nents 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 spectrum
outside the measurement channel.
1. Press the "Span" key to open the span menu.
2. Select the "Manual Span" menu item.
The R&S
FPC 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.
Measurements and Result Displays
