Measurements and Results
R&S
®
FSW
241
User Manual 1173.9411.02 ─ 43
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The maximum number of ranges is 30.
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The minimum number of ranges is 3.
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The reference range cannot be deleted.
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Center the reference range on the center frequency.
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The current "Tx Bandwidth" defines the minimum span of the reference range (see
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Define frequency values for each range relative to the center frequency.
To change the start frequency of the first range or the stop frequency of the last range,
select the appropriate span with the [SPAN] key. You can define a span that is smaller
than the combined span of all ranges. In this case, the measurement includes only the
ranges that lie within the defined span and have a minimum span of 20
Hz. The first
and last ranges are adapted to the given span as long as the minimum span of 20 Hz
is not violated.
Changing the frequency range of the measurement using external mixers
If you change the used frequency range of the measurement by activating or deactivat-
ing an external mixer, the R&S
FSW automatically adapts the span to full span. Thus,
the ranges for the SEM measurement can change, as well.
Sweep points
You can define a minimum number of sweep points for each range. The total number
of available sweep points is then distributed among the ranges in consideration of the
minimum values. If the total number of sweep points is not enough to satisfy the mini-
mum sweep point requirements in all ranges, the R&S
FSW adjusts the global number
of
accordingly. By default, each range has a minimum of one sweep
point.
This allows you to increase the resolution within a specific range for detailed analysis.
You do not have to increase the overall number of sweep points and thus the measure-
ment time for the SEM measurement.
Symmetrical ranges
You can easily define a sweep list with symmetrical range settings, i.e. the ranges to
the left and right of the reference range are defined symmetrically. When symmetrical
setup is activated, the current sweep list configuration is changed to define a symmetri-
cal setup regarding the reference range. The number of ranges to the left of the refer-
ence range is reflected to the right, i.e. any missing ranges on the right are inserted,
while superfluous ranges are removed. The values in the ranges to the right of the ref-
erence range are adapted symmetrically to those in the left ranges.
Symmetrical ranges fulfill the conditions required for "Fast SEM" mode (see
ter 7.6.4.3, "Fast SEM Measurements"
Power classes
If the signal power level to be monitored varies and the limits vary accordingly, you can
define power classes, which can then be assigned to the frequency ranges. Thus, the
Spectrum Emission Mask (SEM) Measurement
