Chapter 2 61
One-Button Measurement Functions
MEASURE (Spectrum Analysis Mode)
One-Button Measurement Functions
2.2.5 O ccupied BW
Occupied Bandwidth integrates the power of the displayed spectrum and puts markers at
the frequencies between which a selected percentage of the power is contained. The
measurement defaults to 99% of the occupied bandwidth power. The power-bandwidth
routine first computes the combined power of all signal responses contained in the trace.
For 99% occupied power bandwidth, markers are placed at the frequencies on either side of
99% of the power. 1% of the power is evenly distributed outside the markers. The
difference between the marker frequencies is the 99% power bandwidth and is the value
displayed. For more information see “Meas Setup (Occupied Bandwidth—OBW)” on
page 177.
The occupied bandwidth function also indicates the difference between the analyzer center
frequency and the center frequency of the channel. This “Transmit Freq Error” is defined
as the difference between the (f1 + f2)/2 and the tuned center frequency of the signal. See
Figure 2-3 on page 62.
The occupied bandwidth measurement can be made in single or continuous sweep mode.
The center frequency, reference level, and channel spacing must be set by the user.
To configure measurement settings, press Meas Setup after selecting Occupied BW. Pressing
Radio Standard after Mode Setup has been selected will access all the Radio Standards
available for which this measurement can be applied. Pressing Meas Control enables you to
pause or restart a measurement, or toggle between continuous and single measurement.
Key Path: MEASURE
Remote Command:
Remote Command Notes: The results for both values are returned in Hz.
Measurement Results Available
Command Results Returned
:CONFigure:OBW
:INITiate:OBW
Not Applicable
:FETCh:OBW?
:MEASure:OBW?
:READ:OBW?
Returns two values that correspond to the Occupied BW and
Transmit Frequency Error in Hertz.
:FETCh:OBW:OBWidth?
:MEASure:OBW:OBWidth?
:READ:OBW:OBWidth?
Returns a single value that corresponds to the Occupied BW in
Hertz.
:FETCh:OBW:FERRor?:MEASure:
OBW:FERRor?
:READ:OBW:FERRor?
Returns a single value that corresponds to the Transmit
Frequency Error in Hertz.
:FETCh:OBW:XDB?
:MEASure:OBW:XDB?
:READ:OBW:XDB?
Returns a single value that corresponds to the x dB BW in
Hertz.