RIGOL
Chapter 2 Functions of the Front Panel of GPSA
2-16
RSA3000E User Guide
VBW
Sets the video bandwidth (VBW) to filter out the noises outside the video band.
Remarks:
Reducing VBW makes the spectral line smoother, so that the low-level signal in
the noise can be detected, but this will also prolong the sweep time (when
sweep time is set to Auto, it will be affected by both RBW and VBW).
You can use the numeric keys, the knob, and the arrow keys on the front panel
to modify this parameter; also you can modify it on the touchscreen. For details,
refer to descriptions in "Parameter Setting".
Table 2-14 VBW
Parameter
Remarks
Default
3 MHz
Range
1 Hz to 10 MHz
Unit
GHz, MHz, kHz, Hz
Knob Step
at 1-3-10 step
Left/Right Arrow Key Step
Up/Down Arrow Key Step
at 1-3-10 step
VBW Mode
Sets the coupling mode of the Span/RBW ratio.
Remarks:
When you set VBW Mode to "Auto", VBW is in auto coupling state. Its value
changes with the RBW, and the value is determined by VBW/RBW ratio. You can
set VBW Mode to "Manual" or directly set the VBW value to change the
coupling mode.
When you perform the Preset operation, the coupling state is Auto.
VBW/RBW Ratio
Sets the ratio of VBW to RBW.
Remarks:
This value is different for different kinds of signals.
Sine signal: 1 to 3 (for faster sweeps)
Pulse signal: 10 (to reduce the impact on the amplitude of transient signals)
Noise signal: 0.1 (to obtain the average of noises)
You can use the numeric keys, the knob, and the arrow keys on the front panel
to modify this parameter; also you can modify it on the touchscreen. For details,
