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R&S FSH
Spectrum Analyzer Mode
Performing Spectrum Measurements
Operating Manual 1173.6275.12 - 30
51
3.1.2 Measuring the Channel Power of Continuously Modulated Signals
The channel power measurement selectively measures the power of modulated
signals. 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 FSH 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. The R&S FSH takes
the following parameters into account:
● display mode (absolute or relative)
● detector
● resolution bandwidth
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
narrow channel filter and so prevents out-of-channel emissions from affecting the
result.
► Press the MEAS key.
► Press the "Meas Mode" softkey.
► Select the "Channel Power" menu item.
The R&S FSH starts to measure the channel power.
By default, the 3GPP WCDMA standard is active. Two vertical lines show the
channel bandwidth.
Screen layout for channel power measurements
1
Standard
2
Channel bandwidth
3
Channel power numerical
4
Channel bandwidth graphical (blue lines)
5
Channel power measurement softkey menu