Technical data

106 Chapter 5
Spectrum Analyzer
Occupied Bandwidth (OBW) Measurement
Spectrum Analyzer
Making a Basic Occupied BW Measurement
NOTE For accurate OBW measurements, it is recommended that you use the
sample or average trace detectors. The default detector type is sample.
In addition, you should use Exponential Average or Repeat Average
with 100 or more averages.
The following example shows how to make an OBW measurement on a
GSM signal broadcasting at 950 MHz.
Step 1. Connect the RF Output of the signal generator to the analyzer RF Input
as shown in Figure 5-27.
Figure 5-27 Setup for OBW Measurement
Step 2. Set a GSM signal on the signal generator with a frequency of 950 MHz
a nd the amplitude set to −10 dBm.
Step 3. Select the spectrum analyzer mode:
Press
Mode, Spectrum Analyzer.
Step 4. Preset the analyzer:
Press
Mode Preset.
Step 5. Set the center frequency and span:
Press
FREQ Channel, Center Frequency, 950, MHz.
Press
Span X Scale, Span, 1, MHz
Step 6.
Select Spectrum Analyzer Occupied BW measurement.
Press
Meas, Occupied BW.
A marker pair will appear on the trace and the occupied bandwidth
value and the integrated power in the OBW are displayed in the data
window below the trace graticule. See Figure 5-28