Specifications

Chapter 9 69
Measuring Digital Communications Signals
Making Burst Power Measurements
Measuring Digital Communications
Signals
Figure 9-1 Full Screen Display of Burst Power Measurement Results
NOTE Press the Return key to exit the full screen display without changing
any parameter values.
Step 6. Select one of the following three trigger methods to capture the bursted
signal (RF burst is recommended, if available):
Press
Trig, RF Burst.
For more information on trigger selections see “Trigger Concepts” on
page 153.
NOTE Although the trigger level allows the analyzer to detect the presence of
a burst, the time samples contributing to the burst power measurement
are determined by the threshold level, as described next.
Step 7. Set the relative threshold level above which the burst power
measurement is calculated:
Press
Meas Setup, Threshold Lvl (Rel), −10, dB.
The burst power measurement includes all points above the threshold
and no points below. The threshold level is indicated on the display by
the green horizontal line (for video triggering it is the upper line). In
this example, the threshold level has been set to be 10 dB below the
relative level of the burst. The mean power of the burst is measured
from all data above the threshold level.
Step 8. Set the burst width to measure the central 200 µs of the burst:
Press
Meas Setup, Meas Method, Measured Burst Width, Burst Width
(Man),
200, µs.
The burst width is indicated on the screen by two vertical white lines.
Manually setting the burst width allows you to make it a long time
interval (to include the rising and falling edges of the burst) or to make
it a short time interval, measuring a small central section of the burst.