Rohde & Schwarz FPC1000, User Manual

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The Spectrum Application
FPC1000
56
User Manual 1178.4130.02 ─ 02
Remote commands to control channel power measurements:
●
Chapter 13.10.1, "Measurements and Result Displays" , on page 179
Available with the optional "Advanced Measurements" application.
The channel power measurement selectively measures the power of modulated sig-
nals. Unlike a power meter that performs measurements over its entire frequency
range, the channel power measurement measures the power of a specific transmission
channel. Other signals in the frequency spectrum don't show in the results.
When measuring the spectrum within a channel, the R&S
FPC1000 uses a resolution
bandwidth that is small compared to the channel bandwidth. It then determines the
total power of the channel by integrating the results on the trace.
That means that you can compare the result to the result that would have been
obtained from a thermal power meter. The small resolution bandwidth acts like a nar-
row channel filter and so prevents out-of-channel emissions from affecting the result.
Selecting the channel power measurement
1. Press the "Meas" key to open the measurement menu.
2. Select the "Measurement Mode" menu item to select the measurement.
3. Select the "Channel Power" menu item.
The R&S FPC1000 starts to measure the channel power.
Two vertical lines indicate the channel bandwidth.
The channel power measurement shows the results and various other information
about the measurement in the diagram header.
●
Power
/
Max Power
Shows the power level measured within the channel. The label changes depending
on the power mode you have selected.
●
Channel BW
Shows the currently selected channel bandwidth.
The diagram footer shows the currently selected center frequency and span .
● About the Measurement ..........................................................................................56
● Configuration ...........................................................................................................57
9.2.1.1 About the Measurement
The following prerequisites and settings are necessary to obtain correct results for the
channel power measurement.
●
Define the correct channel bandwidth.
Only the signal to be measured should be visible in the diagram. An additional sig-
nal would falsify the measurement.
●
Define a sufficient resolution bandwidth .
●
Select the RMS detector .This ensures that the power measurement is always cor-
rect irrespective of the waveform being investigated.
Measurements and Result Displays
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