Common Measurement Settings
R&S
®
FSW
488
User Manual 1173.9411.02 ─ 43
8.6.2.1
Gated Measurements
Like a gate provides an opening in a fence, a gated measurement lets data from the
input signal pass in defined areas only. The
gate
controls exactly when data is included
in the measurement results and when not. The gate is opened by the trigger source,
which is also the gate source.
Gates can be used in two different modes:
●
Level:
The gate opens and the measurement starts when a defined level in the
gate source is exceeded and stops when the gate source drops below the "Gate
Level".
Using a pulsed gate signal in level mode, the following behavior can be achieved:
When the gate source signal is active, the input signal data is collected; when the
gate signal is inactive, the input signal is ignored.
●
Edge:
The gate opens and the measurement starts when a defined level in the
gate source is exceeded and stops when the defined "Gate Length" is reached.
Restrictions
●
The "Gate Mode"
Level
is not supported for Rohde
&
Schwarz power sensors. The
signal sent by these sensors merely reflects the instant the level is first exceeded,
rather than a time period. However, only time periods can be used for gating in
level mode. Thus, the trigger impulse from the sensors is not long enough for a
fully gated measurement; the measurement cannot be completed. For details on
power sensors see
"Using a Power Sensor as an External Power Trigger"
Additionally, a delay time can be defined so that the first few measurement points after
the gate opening are ignored.
Figure 8-30: Effects of Gate mode, Gate delay and Gate length
Trigger and Gate Configuration
