Agilent Technologies E4445A User Manual
86
Chapter 2
Instrument Functions: A - L
BW/Avg
In
st
ru
m
e
nt
Funct
ions
:
A
-
L
Remote Command:
[:SENSe]:BANDwidth|BWIDth:VIDeo <freq>
[:SENSe]:BANDwidth|BWIDth:VIDeo?
[:SENSe]:BANDwidth|BWIDth:VIDeo:AUTO OFF|ON|0|1
[:SENSe]:BANDwidth|BWIDth:VIDeo:AUTO?
Example:
BAND:VID 1 kHz
BAND:VID?
BWID:VID:AUTO ON
BWID:VID:AUTO?
2.2.3
VBW/RBW
Selects the ratio between the video and resolution bandwidths. Video bandwidth wider
than resolution bandwidth (VBW/RBW ratio > 1.000), provides the best peak
measurements of signals such as wideband radar pulses. VBW narrower than RBW
(VBW/RBW ratio < 1.000) reduces the variance of noise-like signals and makes spectral
components close to the noise floor easier to view. The knob and step keys change the ratio
in a 1, 3, 10 sequence. With
than resolution bandwidth (VBW/RBW ratio > 1.000), provides the best peak
measurements of signals such as wideband radar pulses. VBW narrower than RBW
(VBW/RBW ratio < 1.000) reduces the variance of noise-like signals and makes spectral
components close to the noise floor easier to view. The knob and step keys change the ratio
in a 1, 3, 10 sequence. With
Preset Type
set to
Factory
, pressing
Preset
or selecting
Auto Couple
,
Auto All
sets the ratio to 1.000 X. When
VBW/RBW (Auto)
is selected, the ratio is determined as
indicated below.
Table 2-1
VBW/RBW Ratio Auto Rules
Detector Mode
Noise
Marker
Marker
Ratio
Notes
Peak
On
10
Noise response is estimated for wide VBW case
Negative Peak
On
10
Don’t care
Average
On
0.1
Narrow VBW for low-sigma marker readout
Normal
On
0.1
Don’t care (noise marker makes is not valid with
normal detection.)
normal detection.)
Sample
On
0.1
Narrow VBW for low-sigma marker readout
Peak
Off
10
Wide VBW for good impulse BW (pulsed RF)
Negative peak
Off
10
Don’t care
Average
Off
0.1
Narrow VBW for low-sigma trace results
Normal
Off
1.0
Swept analysis CW signal setting
Sample
Off
1.0
Wide VBW for good impulse BW (pulsed RF)