Technical data

Chapter 5 107
Spectrum Analyzer
Occupied Bandwidth (OBW) Measurement
Spectrum Analyzer
Figure 5-28 OBW Measurement Results
Step 7. You can improve the repeatability of the measurements by setting the
Average number to 100 or greater:
Press
Meas Setup, Avg Number, 100, Enter, Trace/Detector, Average.
Step 8. You can change the percentage of power used for calculating the
Occupied BW. The default percentage is 99%.:
Press
Meas Setup, Power, 80, %.
NOTE If you are measuring a narrow signal such as TDMA or PDC, zoom in
on the signal for a more accurate OBW results.
Press
Span X Scale, Span, enter the frequency using the number keypad,
and then press Hz, kHz, MHz, or GHz.
NOTE For an over the air measurement, connect an antenna and an external
filter to the RF input.
The external filter is necessary to eliminate out-of-band signals that
would otherwise reduce the dynamic range of measurements in the
band of interest. The effect of the out-of-band signals is to raise the
noise floor, possibly hiding some or all of the signal of interest. However,
the external filter is optional in this set up:
If you want to limit your search to a specific band of interest, you should
use the filter.
If you want to search beyond a specific band, then you can leave the
filter off.