3 Short-Range Comms & IoT Mode
3.5 Channel Power Measurement
:CHP:BAND:VID?
Notes For numeric entries, the instrument chooses the nearest (arithmetically, on a linear scale, rounding
up) available VBW to the value entered. The 50MHz VBW is defined to mean “wide open”
The values shown in this table reflect the conditions after a Mode Preset
Dependencies Sometimes the displayed Video BW is not actually used to process the trace data:
When the Average Detector is selected and Sweep Type is set to Swept, the video bandwidth filter
cannot be used, because it uses the same hardware as the Average Detector
When the Quasi-Peak, EMI Average or RMS Average detector is selected the VBW is implemented by
the digital IF as part of the detector
When this is the case, VBW still acts to change the Sweep Time, if "Sweep Time" on page 1719 is in
Auto, and still affects the data on other traces for which this is not the case
Couplings Video bandwidth (VBW) is normally coupled to "Res BW" on page 596. If VBW is set to Auto, then
VBW is changed as RBW changes, to maintain the ratio set by VBW:3 dB RBW (usually 10:1 for
measurements that do not have a VBW:3 dB RBW control)
Preset Auto (unless noted in table below)
State Saved Saved in instrument state
Min 1 Hz
Max 50 MHz
Annunciation A “#” mark appears before “VBW” in the annotation when it is not coupled
Annotation In the bottom center of the screen, “VBW <value> <units>” indicates the current video bandwidth
value. Note that for some detectors this is not the value actually used for VBW (see above)
Backwards
Compatibility
Notes
For backwards compatibility, this command supports both the BANDwidth and BWIDth forms
Auto Function
Remote
Command
[:SENSe]:CHPower:BANDwidth:VIDeo:AUTO ON | OFF | 1 | 0
[:SENSe]:CHPower:BANDwidth:VIDeo:AUTO?
Example
:CHP:BAND:VID:AUTO OFF
:CHP:BAND:VID:AUTO?
Preset
ON
VBW Presets
Unless noted in the table below, the Preset value of VBW is Auto.
Mode Preset Value
WCDMA 2.40 MHz
Short Range Comms & IoT Mode User's &Programmer's Reference 599