R&S FSW Series User Manual

Measurements and Results
R&S
®
FSW
214User Manual 1173.9411.02 ─ 43
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RBW << occupied bandwidth (approx. 1/20 of occupied bandwidth, for voice com-
munication type: 300 Hz or 1 kHz)
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VBW ≥ 3 x RBW
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RMS detector
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Span ≥ 2 to 3 x occupied bandwidth
Some of the measurement specifications (e.g. PDC, RCR STD-27B) require measure-
ment of the occupied bandwidth using a peak detector. The detector setting of the
R&S FSW has to be changed accordingly then.
7.4.2 OBW Results
As a result of the OBW measurement the occupied bandwidth ("Occ Bw") is indicated
in the marker results. Furthermore, the marker at the center frequency and the tempo-
rary markers are indicated.
The measurement is performed on the trace with marker 1. In order to evaluate
another trace, marker 1 must be placed on another trace (see Assigning the Marker to
a Trace).
The OBW calculation is repeated if the Search Limits are changed, without performing
a new sweep. Thus, the OBW for a multicarrier signal can be determined using only
one sweep.
Centroid frequency
The centroid frequency is defined as the point in the center of the occupied bandwidth,
calculated using the temporary OBW markers T1 and T2. This frequency is indicated
as a function result ("Occ Bw Centroid") in the marker table.
Frequency offset
The offset of the calculated centroid frequency to the defined center frequency of the
R&S FSW is indicated as a function result ("Occ Bw Freq Offset") in the marker table.
Remote command:
The determined occupied bandwidth can also be queried using the remote command
CALC:MARK:FUNC:POW:RES? OBW or CALC:MARK:FUNC:POW:RES? AOBW. While
the OBW parameter returns only the occupied bandwidth, the AOBW parameter also
returns the position and level of the temporary markers T1 and T2 used to calculate the
occupied bandwidth.
CALC:MARK:FUNC:POW:SEL OBW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:SELect on page 839
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>[:STATe] on page 840
CALC:MARK:FUNC:POW:RES? OBW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 837
Occupied Bandwidth Measurement (OBW)

R&S FSW Series Specifications

General

Brand	R&S
Model	FSW Series
Category	Measuring Instruments
Language	English