Measurements
R&S
®
FSW
226
User Manual 1173.9411.02 ─ 19
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"To perform an MSR SEM measurement"
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"To perform a Multi-SEM measurement"
To select an SEM measurement
► Press the MEAS key, then select the "Spectrum Emission Mask" measurement.
To perform an SEM measurement according to a standard
► Load the settings file as described in
"How to load an SEM settings file"
on page 229 and start a measurement.
To configure a user-defined SEM measurement
1. Define the span of the signal to be monitored in the general span settings.
2. Split the frequency span of the measurement into ranges for signal parts with simi-
lar characteristics.
Starting from the center frequency, determine which sections of the signal to the
left and right can be swept and monitored using the same parameters. Criteria for
such a range definition may be, for example:
● The signal power level
● The required resolution bandwidth or sweep time
● Transducer factors
● Permitted deviation from the defined signal level, i.e. the required limit values
for monitoring
If the signal consists of a transmission channel and adjacent channels, the channel
ranges can usually be used for the range definition.
3. If the signal power level to be monitored may vary and the limits will vary accord-
ingly, define power classes. For each range of levels that can be monitored in the
same way, define a power class.
a) Select the "Overview" softkey, then select the "SEM Setup" button and switch
to the "Power Classes" tab.
b) Add a power class by selecting the "Add" button.
c) Enter the start and stop power levels to define the class.
d) Select the power classes to be used for the current measurement: either a spe-
cific class, or all classes, to have the required class selected automatically
according to the input level measured in the reference range.
4. Select the "Sweep List" tab of the "Spectrum Emission Mask" dialog box.
5. Insert the required ranges using the "Insert before Range" and "Insert after Range"
buttons, which refer to the currently selected range (the reference range by
default).
If the signal trace is symmetric to the center frequency, activate the "Sym Setup"
option to make setup easier and quicker.
Spectrum Emission Mask (SEM) Measurement
