HP 8753D - Page 365

P
ower Loss
Correction List
If
a directional
coupler
or
power
splitter
is
used
to
sample
the
RF
power
output of
the analyzer
,
the
RF signal
going
to
the
power
meter
may
be
dierent
than
that
going
to the
test device
.A
directional
coupler will
attenuate
the
RF
signal
by
its
specied
coupling
factor
.
The
dierence
in
attenuation between
the
through
arm
and
the
coupled
arm
(coupling
factor)
must
be
entered
using
the loss/sensor
list menu.
Non-linearities
in
either
the
directional
coupler
or
power
splitter
can
be
corrected
in
the
same
way
.
P
ower
loss
information
is
entered
in
much
the
same
way
as
limit
line
parameters
.
Up to
12
segments
may
be
entered,
each
with
a
dierent
attenuation
value
.
The
entered
data
will
not
be
lost
if
the
instrument's
power
is
cycled.
P
ower
Sensor
Calibration F
actor List
Two
power sensor
calibration data
lists can
be
created
in
the
analyzer
.
No
single
power
sensor
covers
the entire
frequency range
of the
analyzer
,
therefore
the
calibration
data
for
two
dierent
power sensors
must be
available.
The
entered
data
will
not
be
lost
if
the
instrument's
power
is cycled.
Speed
and
A
ccuracy
The
speed
and
accuracy
of
a
power
meter
calibration
vary
depending
on
the
test
setup
and
the
measurement
parameters
.
F
or
example
,
number
of
points
,
number of
readings,
if
the
power
is
less
than
0
20
dBm,
continuous
versus
sample
and
sweep
mode
.A
ccuracy is
improved
if
you
set
the
source
power
such
that
it
is
approximately
correct
at
the measurement
port. P
ower
meter
calibration
should
then
be
turned
on.
With
number
of
readings
=
2,
very accurate
measurements
are
achieved.
T
able
6-6
shows
typical
sweep
speed and
power
accuracy
.
The
times
given
apply
only
to
the
test
setup
for
continuous
correction
or
for
the rst
sweep
of
sample-and-sweep
correction.
The
typical
values
given
in
T
able
6-6 were
derived under
the
following
conditions:
T
est
Equipment
Used
HP
8753D network
analyzer
HP
436A power
meter
HP
8485A power
sensor
Stimulus
Parameters
The time required to perform a power meter calibration depends on the source power and
number of points tested. The parameters used to derive the typical values in T
able 6-6 are as
follows:
number of points: 51, 100 kHz to 3 GHz
test port power: equal to calibration power
Sweep time is linearly proportional to the number of points measured.
For example
, a sweep
taking 49 seconds at 51 points will take approximately 98 seconds if 101 points are measured.
6-98 Application and Operation Concepts