Keysight x-series Programmer's Reference

3 VMA Mode
3.6 Occupied BW Measurement
Res BW
Activates the resolution bandwidth active function, which allows you to manually set
the resolution bandwidth (RBW) of the instrument.
Normally, Res BW (Auto) selects automatic coupling of the Res BW to "Span" on
page 1003 using the ratio set by Span:3dB RBW (some measurements do not have
a Span:3dB RBW control, in which case the measurement chooses the optimal
ratio). To decouple the resolution bandwidth, press the Auto/Man toggle on the Res
BW control, or simply enter a different value for Res BW.
When the Res BW is manually selected, it may be returned to the coupled state by
pressing the Auto/Man toggle on the Res BW control. This may also be done by
pressing "Auto Couple" on page 1825 or by performing a Preset.
When Res BW is set to Auto, the bandwidth selected depends on "RBW Filter Type"
on page 987.
Only certain discrete resolution bandwidths are available. The available bandwidths
are dependent on Filter Type or EMC Standard. If an unavailable bandwidth is
entered with the numeric keypad, the closest available bandwidth is selected.
Remote
Command
[:SENSe]:OBWidth:BANDwidth[:RESolution] <bandwidth>
[:SENSe]:OBWidth:BANDwidth[:RESolution]?
[:SENSe]:OBWidth:BANDwidth[:RESolution]:AUTO ON | OFF | 1 | 0
[:SENSe]:OBWidth:BANDwidth[:RESolution]:AUTO?
Example
:OBW:BAND 5 MHz
:OBW:BAND?
:OBW:BAND:AUTO ON
:OBW:BAND:AUTO?
Notes For numeric entries, all RBW Types choose the nearest (arithmetically, on a linear scale, rounding up)
available RBW to the value entered
The setting and querying of values depend on the current bandwidth type
Couplings Sweep time is coupled to RBW. As RBW changes, the sweep time (if set to Auto) is changed to maintain
amplitude calibration
"Video BW" on page 986 is coupled to RBW. As the resolution bandwidth changes, the video
bandwidth (if set to Auto) changes to maintain the ratio of VBW/RBW (10:1)
When Res BW is set to Auto, the resolution bandwidth is auto-coupled to the span. The ratio of
Span/RBW is approximately 106:1 when auto coupled. When Res BW is set to Man, and the
bandwidths are entered manually, these bandwidths are used regardless of other instrument settings
Preset Auto, unless noted in "RBW Presets" on page 986 below
See table below
State Saved Saved in instrument state
985 Vector Modulation Analyzer Mode User's &Programmer's Reference

Keysight x-series Specifications

General

Analysis Bandwidth	Up to 1 GHz (depending on model)
Real-Time Bandwidth	Up to 1 GHz (depending on model)
Form Factor	Benchtop
Connectivity	LAN, USB, GPIB
Resolution Bandwidth	1 Hz to 10 MHz (depending on model)