206
Concepts
Time Gating Concepts
Figure 15-16 Time-domain Parameters
In Figure 15-16, the parameters are:
• Pulse repetition interval (PRI) is 5 ms.
• Pulse width (τ) is 3 ms.
• Signal delay (SD) is 1 ms for positive edge trigger (0.6 ms for negative edge
trigger).
• Gate delay (D) is 2.5 ms.
• Setup time (SUT) is 1.5 ms.
Step 2. Set the signal analyzer sweep time:
Gated LO: Sweep time does not affect the results of gated LO unless the sweep time
is set too fast. In the event the sweep time is set too fast, Meas Uncal appears on
the screen and the sweep time will need to be increased.
Gated Video: Sweep time does affect the results from gated video. The sweep time
must be set accordingly for correct time gating results. The recommended sweep
time is at least the number of sweep points – 1 multiplied by the PRI (pulse
repetition interval). Measurements can be made with sweep times as fast as (sweep
points–1)*(PRI–τ).
Step 3. Locate the signal under test on the display of the signal analyzer. Set the center
frequency and span to view the signal characteristics that you are interested in
measuring. Although the analyzer is not yet configured for correct gated
measurements, you will want to determine the approximate frequency and span in
To Next Page
Loading...
Need help?
General
