HP 8753D - Calibration Standards

Calibration
Standards
The
quality
of
the
error-correction
is
limited
by
two
factors:
(1) the
dierence between
the
model
of
the
calibration
standards
and
the
actual
electrical characteristics
of those
standards,
and
(2)
the
condition
of
the
calibration
standards
.T
o make
the highest
quality measurement
calibration,
follow
the
suggestions
below:
use
the
correct
standard
model
inspect
the
calibration
standards
clean
the
calibration
standards
gauge
the
calibration
standards
use
correct
connection
techniques
If
you
want
to
use calibration
standards other
than the
default sets
,
you
must
change
the
standard
model.
(Refer
to
\Modifying Calibration
Kit Standards"
located later
in this
chapter
.)
After
you
enter
the
mathematical model
for the
new calibration
standards,
the
analyzer
can
then
use
the
model
that
corresponds
to the
new standards
.
Compensating
for
the
Electrical
Delay
of
Calibration
Standards
Short
and open
calibration
standards
in
the
3.5
mm,
2.4
mm,
and
2.92
mm
connector
types
have
a certain
amount
of
electrical
delay
.
The
analyzer
compensates
for
this
delay
by
osetting
the
calibration
results
by
the
total
amount
of
electrical
delay
caused
by
the
calibration
standard
in
both
the
forward
and
reverse
direction.
As
a
result,
if
these
standards
are
measured after
a
calibration,
they
will
not
appear
to
be
\perfect"
shorts
or
opens
.
This
is
an
indication
that your
analyzer
is
working
properly
and
that
it
has
successfully
performed
a
calibration.
Note
If
you
enter
the
opposite
amount
of
electrical
delay
that
was
used
by
the
analyzer
during
calibration,
then
the
short
calibration
standard
will
appear
to
be
\perfect."
The
open
calibration
standard
has
additional
phase
shift
caused
by
fringing
capacitance
.
See
\Calibration
Considerations"
in
Chapter
6,
\Application
and
Operation
Concepts
."
Clarifying
Type-N
Connector
Sex
When
you
are
performing
error-correction
for
a
system
that has
type-N test
port connectors
,
the softkey
menus label
the sex
of the
test
port
connector
-
not
the
calibration
standard
connector
.
F
or
example
,
the label
N
N
N
N
N
N
N
N
N
N
NN
NN
NN
NN
N
N
N
N
N
N
N
N
N
N
N
SHORT
(F)
refers
to
the
short
that will
be connected
to the
female
test port
.
When to Use Interpolated Error-Correction
You may want to use interpolated error-correction when you
choose a subset of a frequency
range that you already corrected, when you change the number
of points
, or when you change
to CW
. This feature also allows you to change the
parameters in a 2-port correction, such as IF
bandwidth, power
, or sweep time
. The analyzer calculates the systematic
errors from the errors
of the original correction.
The quality of the interpolated error-correction depends on the amount of phase shift and
amplitude change of the error coecients between measurement points. If the phase shift
is < 180

per ve measurement points, the interpolated error-correction can be a great
improvement over uncorrected measurement.
To activate interpolated measurement correction, press 4
CAL
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
INTERPOL ON
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
CORRECTION ON .
When interpolation is in use, the notation C? will appear on the analyzer display.
5-6 Optimizing Measurement Results