HP 8753D - Page 137

High Dynamic
Range Swept
RF/IF Conversion
Loss
The
HP
8753D's
frequency
oset mode
enables the
testing of
high dynamic
range frequency
converters
(mixers),
by
tuning
the
analyzer's
high dynamic
range receiver
above or
below its
source
,
by
a
xed
oset.
This capability
allows the
complete measurement
of both
pass and
reject
band
mixer
characteristics
.
The
analyzer
has
a
35 dB
dynamic range
limitation on
measurements made
directly
with
its
R
(phaselock)
channel.
F
or
this
reason,
the measurement
of high
dynamic range
mixing
devices
(such
as
mixers
with
built
in
amplication and
ltering) with
greater than
35
dB
dynamic
range
must
be
made
on
either
the
analyzer's A
or B
channel, with
a
reference
mixer
providing
input
to
the
analyzer's
R-channel
for
phaselock.
This
example
describes the
swept IF
conversion loss
measurement of
a
mixer
and
lter
.
The
output
ltering
demonstrates the
analyzer's ability
to make
high dynamic
range
measurements
.
T
o
avoid the
complexity of
performing a
separate power
meter
calibration
over
the
RF
frequency
range
while the
mixer under
test and
reference mixer
are
operating,
a
broad
band
power
meter
calibration
is
used. The
broad band
calibration
covers
the
entire
range
of
IF
and
RF
frequencies
.
1.
Set
the
following
analyzer
parameters:
4
PRESET
5
4
ST
ART
5
4
100
5
4
M/

5
4
STOP
5
4
2.5
5
4
G/n
5
4
MENU
5
N
N
N
N
NN
N
N
N
N
N
N
N
N
N
N
N
POWER
N
N
N
N
NN
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
NN
N
N
N
N
N
N
N
N
N
N
PWR RANGE
MAN
4
0
54
x1
5
2.
Calibrate
and
zero
the
power
meter.
3.
Connect
the
measurement
equipment
as
shown
in Figure
3-10
.
Caution
T
o
prevent
connector
damage
,
use
an
adapter (HP
part number
1250-1462)
as
a
connector
saver
for
R
CHANNEL
IN.
3-12 Making Mixer Measurements