R&S FSH
Spectrum Analyzer Mode
Performing Spectrum Measurements
Operating Manual 1309.6275.12 - 14
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2 Spectrum Analyzer Mode
The default operating mode of the R&S FSH is the spectrum analyzer. The spectrum
analyzer provides the functionality to perform measurements in the frequency domain,
e.g. to identify the power of signals.
2.1 Performing Spectrum Measurements
In addition to basic spectrum measurements, the R&S FSH provides several specific
measurements. These measurements, also in combination with one of the available
accessories, allow you to perform advanced and more complex measurement tasks.
2.1.1 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:
C
display mode (absolute or relative)
C
detector
C
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.
M
Press the MEAS key.
M
Press the "Meas Mode" softkey.
M
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.
