Common Analysis and Display Functions
R&S
®
FSPN
174
User Manual 1179.4363.02 ─ 01
7.5
Limit Lines
Limit lines help you analyze a measurement trace.
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Limit Line Settings and Functions
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7.5.1
Basics on Limit Lines
Limit lines are used to define amplitude curves or spectral distribution boundaries in
the result diagram which are not to be exceeded. They indicate, for example, the upper
limits for interference radiation or spurious waves which are allowed from a device
under test (DUT). When transmitting information in TDMA systems (e.g. GSM), the
amplitude of the bursts in a time slot must adhere to a curve that falls within a specified
tolerance band. The lower and upper limits may each be specified by a limit line. Then,
the amplitude curve can be controlled either visually or automatically for any violations
of the upper or lower limits (GO/NOGO test).
The R&S
FSPN supports limit lines with a maximum of 200 data points. Eight of the
limit lines stored in the instrument can be activated simultaneously. The number of limit
lines stored in the instrument is only limited by the capacity of the storage device used.
Limit line data can also be exported to a file in ASCII (CSV) format for further evalua-
tion in other applications. Limit lines stored in the specified ASCII (CSV) format can
also be imported to the R&S
FSPN for other measurements.
Compatibility
Limit lines are compatible with the current measurement settings, if the following
applies:
●
The x unit of the limit line has to be identical to the current setting.
●
The y unit of the limit line has to be identical to the current setting.
Validity
Only limit lines that fulfill the following conditions can be activated:
●
Each limit line must consist of a minimum of 2 and a maximum of 200 data points.
●
The frequencies/times for each data point must be defined in ascending order;
however, for any single frequency or time, two data points may be entered (to
define a vertical segment of a limit line).
●
Gaps in frequency or time are not allowed. If gaps are desired, two separate limit
lines must be defined and then both enabled.
●
The entered frequencies or times need not necessarily be selectable in
R&S
FSPN. A limit line may also exceed the specified frequency or time range.
The minimum frequency for a data point is -200 GHz, the maximum frequency is
200 GHz. For the time range representation, negative times may also be entered.
The allowed range is -1000 s to +1000 s.
Limit Lines
