Agilent Technologies 4395A - Page 423

Calibration
for
Network
Measurement
ARBITRARY
IMPEDANCEs
are assigned
a standard
type (LO
AD), but
with an
arbitrary
impedance
(dierent from
system Z
0
).
Oset
and Delay
Osets
may be
specied with
any standard
type.
This
means
dening
a
uniform
length
of
transmission
line to
exist between
the
standard
being
dened
and
the
actual
measurement
plane
.F
or reection
standards,
the
oset
is
assumed
to
be
between
the
measurement
plane
and
the standard
(one-way
only).
F
or
transmission
standards
,
the
oset
is
assumed
to
exist
between
the two
reference
planes
(in
eect,
the
oset
is
the
THRU).
Three
characteristics
of
the
oset can
be
dened:
its
delay
(length),
loss
,
and
impedance
.
Oset
Delay species
the
one-way
electrical
delay
from
the
measurement
(reference)
plane
to
the standard,
in
seconds
(s).
(In
a
transmission
standard,
oset
delay
is
the
delay
from
plane
to
plane
.)
Delay
can
be
calculated
from
the
precise
physical
length
of
the
oset,
the
permittivity
constant
of
the
medium,
and
the
speed
of
light.
Oet
Loss
species
energy
loss
,
due
to
skin
eect,
along
a
one-way
length
of
coaxial
cable
oset.
The
value
of
loss
is
entered
as
ohms/nanosecond
(or
Giga
ohms/second)
at
1
GHz.
Oset Z
0
species the
characteristic
impedance
of
the
coaxial
cable
oset.
This
is
not
the
impedance of
the
standard
itself.
Note
Numerical
data for
most Agilent
T
echnologies
calibration
kits
is
provided
in
the
calibration
kit manuals
.
Specifying
the
Standard Class
Once
a
standard
is specied,
it
must
be
assigned
to
a
standard
class
.
This
is
a
group
of
from
one
to
seven
standards
that is
required
to
calibrate
for
a
single
error
term.
The
standards
within
a
single
class
are assigned
to
locations
A
through
G
as
listed
on
the
Standard
Class
Assignments
T
able
(
Table
A-3
).
A
class
often
consists
of
a
single
standard,
but
may
be
composed
of
more
than
one
standard.
Table
A
-3.
Standard
Class
Assignments
T
able
Class A B C D E F G Standard
Class
label
S
11A
S
11B
S
11C
S
22A
S
22B
S
22C
Forward Transmission
Reverse Transmission
Forward Match
Reverse Match
Response
Response & Isolation
Basic Measurement Theory A-47