HP 8753D - Page 264

Reducing Trace
Noise
Y
ou
can
use
two analyzer
functions to
help reduce
the eect
of noise
on the
data trace:
activate
measurement
averaging
reduce
system
bandwidth
T
oA
ctivate
A
veraging
The
noise
is
reduced
with
each
new
sweep
as
the
eective
averaging
factor
increments
.
1.
Press 4
AV
G
5
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NN
AVERAGING FACTOR
.
2.
Enter
a
value
followed
by
4
x1
5
.
3.
Press
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AVERAGING
ON
.
Refer
to
the
\Application
and
Operation
Concepts"
chapter
for
more
information
on
averaging.
T
o
Change
System
Bandwidth
By
reducing
the
system bandwidth,
you reduce
the noise
that is
measured
during
the
sweep
.
While
averaging requires
multiple
sweeps
to
reduce
noise
,
narrowing
the
system
bandwidth
reduces
the
noise
on
each
sweep
.
1.
Press
4
A
V
G
5
N
N
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N
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N
N
IF
BW
.
2.
Enter
the
IF
bandwidth
value
that
you
want,
followed
by 4
x1
5
.
Narrower
system
bandwidths
cause
longer
sweep
times
.
When
in
auto
sweep time
mode
,
the
analyzer
uses
the
fastest
sweep
time
possible
for
any
selected
system
bandwidth.
Auto
sweep
time
mode
is
the
default
(preset)
analyzer
setting.
Reducing
Receiver
Crosstalk
T
o
reduce
receiver
crosstalk
you
can
do
the
following:
perform
a
response
and
isolation
measurement
calibration
set
the
sweep
to
the
alternate
mode
Alternate sweep is
intended for measuring wide dynamic range devices
, such as high pass and
bandpass lters
.
This sweep mode removes a type of leakage term through the device under
test, from one channel
to another
.
To set the alternate sweep
,press
4
CAL
5
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MORE
NNNNNNNNNNNNNNNNNNNNNNNNN
NNNNNNNNNNNNNNNNNNNNNNNNN
NNN
ALTERNATE A AND B
.
Refer to the procedures
, located earlier in this chapter for a response and isolation
measurement
calibration procedure
.
Optimizing Measurement Results 5-57