Agilent Technologies E7405A User Manual
Chapter 1
37
Making Basic Measurements
Measuring Low Level Signals
9.
Place the signal at center frequency by pressing
Peak Search
,
Marker
→
,
Mkr
→
CF
.
10.
Press
BW/Avg
,
Res BW
, and then
↓
. The low level signal appears
more clearly because the noise level is reduced. As shown in
A
#
mark appears next to the
Res BW
annotation at the lower left
corner of the screen, indicating that the resolution bandwidth is
uncoupled. As the resolution bandwidth is reduced, the sweep time
is increased to maintain calibrated data.
uncoupled. As the resolution bandwidth is reduced, the sweep time
is increased to maintain calibrated data.
Figure 1-29
Decreasing Resolution Bandwidth
Measuring Low Level Signals Example 3:
Narrowing the video filter can be useful for noise measurements and
observation of low level signals close to the noise floor. The video filter
is a post-detection low-pass filter that smooths the displayed trace.
When signal responses near the noise level of the analyzer are visually
masked by the noise, the video filter can be narrowed to smooth this
noise and improve the visibility of the signal. (Reducing video
bandwidths requires slower sweep times to keep the analyzer
calibrated.)
observation of low level signals close to the noise floor. The video filter
is a post-detection low-pass filter that smooths the displayed trace.
When signal responses near the noise level of the analyzer are visually
masked by the noise, the video filter can be narrowed to smooth this
noise and improve the visibility of the signal. (Reducing video
bandwidths requires slower sweep times to keep the analyzer
calibrated.)
Using the video bandwidth function, measure the amplitude of a low
level signal.
level signal.
1.
Connect a signal generator to the analyzer input.
2.
Set the signal generator frequency to 300 MHz with an amplitude of
−
80 dBm.