User`s guide

122 N9320A Spectrum Analyzer
5 One-Button Measurements
OBW Span Specifies the range of integration used in calculating the
total power from which the percent occupied bandwidth is
then calculated. The analyzer span will be set to the same
value as the OBW Span for the measurement. OBW Span
should be set to
approximately 2 times the expected occupied
bandwidth result. The range is from 100 Hz to 3 GHz.
Key access:
> Occupied BW
x dB Specifies the power level used to determine the emission
bandwidth as the number of dB down from the highest
signal point, within the occupied bandwidth span. This
function is an independent calculation from the OBW
calculation. The x dB Bandwidth result is also called the
emissions bandwidth, or EBW. This will set two arrows to
your specified dB value below the maximum power and
compute the total power between the arrows. Frequencies f1
and f2 are determined as the furthest frequencies x dB
below and above summit, respectively. The emission
bandwidth is then calculated as f2 – f1 as shown by the
arrows indicated in Figure 29 (note that the diamond
markers are for the OBW function). The range is from –100.0
to –0.1 dB.
Key access:
> Occupied BW
Meas
Meas
NOTE
The asterisk next to the x dB bandwidth value in Figure 29 indicates
the results may not have been determined with optimal analyzer
settings. If emission bandwidth is your primary interest, select Max
Hold. Then change detector mode to peak by pressing
>
Detector > Positive Peak. Acquiring peak data ensures accuracy of
this measurement.
Det/
Display