HP 8753D - Page 421

However
,the
ports labeled
RF and
IF
on
most
mixers
are
not
consistently
connected
to
the
analyzer's
source and
receiver
ports
,
respectively
.
These
mixer
ports
are
switched,
depending
on
whether a
down
converter
or
an
upconverter
measurement
is
being
performed.
It
is important
to
keep
in
mind
that
in
the
setup
diagrams
of
the
frequency
oset
mode,
the
analyzer's
source and
receiver
ports
are
labeled
according
to
the
mixer
port
that
they
are
connected
to.
In
a
down
converter
measurement
where
the
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N
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NN
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N
N
N
N
N
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N
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N
N
N
N
N
N
NN
N
DOWN
CONVERTER
softkey
is
selected,
the
notation
on
the
analyzer's setup
diagram indicates
that the
analyzer's
source
frequency
is
labeled
RF,
connecting to
the
mixer
RF
port,
and
the
analyzer's
receiver
frequency
is
labeled
IF
, connecting
to the
mixer
IF
port.
Because
the RF
frequency can
be greater
or
less
than
the
set
LO
frequency
in
this
type
of
measurement,
you
can select
either
N
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N
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N
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N
N
N
N
RF
>
LO or
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N
N
N
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NN
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N
N
N
N
N
N
N
N
N
N
RF
<
LO .
Figure
6-92.
Down
Converter
P
ort
Connections
6-154 Application and Operation Concepts