Agilent Technologies Printer Accessories 85671A Manuale Utente
Measurement
Considerations
O sets
1
MHz
F
or
measurements
at
o sets
of
1
MHz
the
spectrum
analyzer
noise
oor
is
usually
about
0133
dBm.
T
o
get
this
measurement
range
you
must
select
0
dB
input
attenuation
before
entering
the
utility
.
Caution
Input
attenuation
helps
protect
the
spectrum
analyzer
input
from
being
damaged
by
too
much
power
from
the
device
being
tested.
The
use
of
0
dB
input
attenuation
should
be
minimized
to
protect
the
spectrum
analyzer
.
Slowly
Drifting
Signals
A
log
plot
measurement
can
be
made
on
a
slowly
drifting
signal
using
the
tracking
function,
but
the
measured
value
will
be
slightly
inaccurate
.
The
maximum
drift
rate
that
can
be
tracked
will
depend
on
instrument
settings
such
as
minimum
o set
frequency
and
the
amount
of
averaging.
Depending
on
the
direction
of
the
drift,
the
phase
noise
will
appear
either
higher
or
lower
than
it
actually
is
.
System
Noise
Floor
The
system
noise
oor
should
be
checked
with
a
clean
source
for
the
frequency
o sets
that
will
be
measured.
The
signal
frequency
should
be
the
same
as
the
signal
to
be
measured,
since
the
system
phase
noise
is
a
function
of
the
spectrum
analyzer
center
frequency
.
Do
NOT
use
the
internal
calibrator
to
nd
the
noise
oor
because
phase
noise
cancellation
will
occur
which
will
make
the
noise
oor
appear
to
be
lower
than
it
actually
is
.
Use
of
the
Bottom
Division
of
the
Display
Phase
noise
measurements
made
in
the
bottom
division
of
the
display
will
not
be
as
accurate
as
those
made
in
the
remainder
of
the
display
.
If
measurements
are
occurring
in
the
bottom
division
the
reference
level,
set
in
the
utility
,
should
be
decreased
(made
more
negative
.)
Using
the
Phase
Noise
Utility
2-9