HP 8753D - Page 249

A
dapter
Removal
The
adapter
removal
technique
provides
a
means
to
accurately
measure
noninsertable devices
.
The
following
adapters
are
needed:
A
dapter
A1,
which
mates
with
port
1
of the
device,
must be
installed on
test set
port 1.
A
dapter
A2,
which
mates
with
port
2
of
the
device,
must be
installed on
test set
port
2.
A
dapter
A3
must
match
the
connectors
on
the test
device.
The eects
of
this
adapter
will
be
completely
removed
with
this
calibration
technique
.
Figure 5-12.
Adapters
Needed
The following requirements must also be met:
Calibration standards for performing a 2-port error correction for
each connector type
.
Specied electrical length of adapter A3 within
6 1/4 wavelength for the measurement
frequency range.
For each port, a separate 2-port error correction needs to be performed to create two
calibration sets
. The adapter removal algorithm uses the resultant data from the two
calibration sets and the nominal electrical length of the adapter to compute the adapter's
actual S-parameters. This data is then used to generate a separate third calibration set in
which the forward and reverse match and tracking terms are as if port 1 and port 2 could be
connected. This is possible because the actual S-parameters of the adapter are measured with
great accuracy, thus allowing the eects of the adapter to be completely removed when the
third cal set is generated.
5-42 Optimizing Measurement Results