Agilent Technologies HP 83711A - Page 135

Ke
ys/Shifted
Functions
EXT METER
Advantages
of P
ower Meter
Leveling
When power
meter leveling
is used,
power
level
correction
is
continuous
.
External power
meter leveling
has the
advantages of
better
accuracy
and
temperature stability
,and
improved vernier
linearity over
external
diode
detector leveling.
Using a
sensitive
power
sensor
allows
ALC
at
levels
as
low
as the
power meter
and
sensor
can
measure
.
Disadvantages
of
P
ower
Meter
Leveling
One
disadvantage
of
power
meter
leveling
is
a
longer
settling time
than
diode
detector
or
internal
leveling.
The
settling
time
is
dependent on
the
power
range
and
sensor
used.
The
synthesizer
assumes
a
settling
time
of two
seconds
to
allow
the
sensor
to
reach
the
correct
power
level.
Depending
on
the
power
sensor and
range
being
used,
the
power
meter
might
or
might
not
have
nished
settling. P
ower
is
typically
settled
within
two
seconds
for
the
two
highest
ranges of
the
power
meter
.
External
power
meter
leveling
requires
that external
equipment be
connected
to
the
synthesizer
.
N
O
T
E
Before
selecting
4
EXT
METER
5
,
you
should
adjust
the
power
level
using
internal
leveling
so
that
the
step
attenuator is
set to
the
correct
setting.
6-23