Agilent Technologies HP 83711A - Page 130

Ke
ys/Shifted
Functions
EXT DIODE
Advantages
of Diode
Detector Leveling
When diode
detector leveling
is used,
power
level
correction
is
continuous
.
External diode
detector leveling
has the
advantage of
faster
settling
time
than
power meter
leveling. The
settling time
is variable
and
is
dependent
on
the
devices in
the external
leveling
loop
.
Disadvantages
of
Diode
Detector
Leveling
The
diode
detector
must
be
capable
of
producing
between
1mV
and 1
V
of
ALC
voltage
for
the
power
level
at
the
sampling
point. This
typically restricts
the
lower
limit
at
which
external
diode
detector
leveling
will function.
Diode
detector
leveling
might
not
provide
an
accurate
power
display
on
the
synthesizer
if
the
diode
detector
is
operating
outside
of
the
square
law
region.
Diode
detector
leveling
also
does not
provide
temperature
compensation.
P
ower
level
recalibration
might
be required
in
environments
that
are
not
temperature
stabilized.
External
diode
detector
leveling
requires
that external
equipment be
connected
to
the
synthesizer
.
N
O
T
E
Before
selecting
4
EXT
DIODE
5
,
you
should
adjust
the
synthesizer
power
level
using
internal
leveling
so
that the
step attenuator
is
set
to
the
correct
setting.
6-18