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INTRODUCTION
The HP 8756A scalar
network
analyzer
and the HP 8350B sweeper provide a powerful
scalar
analysis
system for
RF
and microwave
reflection and transmission measurements.
However,
some applications
require great-
er frequency accuracy and
/
or stabili ty than
the HP 8350B can
provide
.
Adding
the HP
53448 source synchronizer to this system can
greatly enhance
the
frequency
accuracy and
stability of scalar
measurements
by
phase
locking the sweeper output to
a
time base
which
is
stable to
within
5 parts in ICE-IO
per day.
This note descr ibes
the
local
operation
of
the
HP
8756A/ 8350B/
5344S
system and provides examples of a number of
measurement
configurations.
It
is intend-
ed to supplement the information
available
in the Operating and Service
Manuals of the
various
instruments
and
several
useful
product
notes.
Appendix
I contains a
list
of these documents
and their HPpart numbers
.
The HP
53448 system consists of
two
parts
,
a
microwave
frequency
counter
(either an
HP
5342A or
an HP 5343A) and the HP
5344A
microwave source synchronizer.
This
system
can phase lock a signal
source
,
in
this
case the
sweeper
,
with 1 Hz resolution
ov
er
a
broad
frequency range (500
MHz-18 GHz
with
the
HP
5342A counter
and
500
MHz
-
26
.
5
GHz for
the HP
5343A
counter)
.
The HP
53445
also
provides
useful
features,
such
as
subharmonic
/
offset
locking and AUTO LOCK.
Subharmonic/
offset
locking can
simplify
the
RF
measurement
hardware
.
AUTO
LOCK
can be
used
to
set
up the sweeper automatically
while
locking
.
These
fu
nctions will
be
described in later sections.
S ETTI
NG
OP
MEASUREMENTS
Synchronized
measurements
can be
made
in
four
modes:
CW
for
single
frequency
measurements,
CF/
6F
and
STRT/
STOP,
both
for
narrowband locked sweeps up to 40 MHz
wide, and
LK/
R
for
wideband "lock
and roll"
sweeps.
This
section
describes
in detail
how to set up and perform
measurements
in
all
four
measurement
modes
(CW,
CF
/
L'::..F,
STRT/
STOP,
LK/
R) with a basic
configu
ration
using
the
8756
System
Interface, normal
locking
and MANUAL
LOCK
.
The following instructions
describe how
to
set
up the
hardware
for measurements
in
our
basic configuration.
1
.
On the HP 5344A rear panel,
a) Set the
MODE
switch to the
"NORM"
position.
This selects normal
locking
mode
.
b) Set
the
LOOP BANDWIDTH swi tch
to
the
"
WE
"
position.
This
selects
wideband
locking
loop
bandwidth.
See
the
HP
53
445
Operating and Service
Manual
for
details.
3
8756
c)
Set the SYS CONT switch
(top
switch
on
the
ADDRESS
DIP
switch)
to
the
"0"
position.
Thi
s
sets
up
the
MANUAL LOCK
mode
.
If this switch
is in
the
"I" position
for
system control
(used
in
AUTO LOCK)
then
the
"CONT" annunciator will
appear
on
the front
panel
of the HP
5344A.
2. On the counter
,
set the time base
switch to
the
"INT" position
.
This
selects
the
counter's internal time
base.
3. Connect the
HP-IB cable
from the 8756
System Interface to
the
HP
83505, as
shown
in
figure
1.
HP
8756A
Scalar
Network
Analvzer
Synem
Interface "-
.
1
0
"
;;:
I
-V
-
o
00
HP 83508
Sweep ChcillltOf
"' >
r:
-
.I:
o
0
0
HP
53445
M
jcrow~ve
Source Synchronizer
f
: o
t
~
j
SYS CaNT
Switch to
..
~
..
Figure
I.
Hp·IB
conneClion for
MANUAL
LOCK.
4. Connect
the cables
for the control
signals
as shown
in figure 2.
In any
mode
,
the HP 8756A requires a O-lOV
sweep
ramp (SWEEP
IN
O-
lOV) and
a
Z
axis blanking pulse
(POS
Z BLANK
)
for the display
.
The sweep times are
determined by the device generating
the sweep
ramp.
Figure
2 shows the
system's control signals
,
includ-
ing
the
sweeps, Z axis blanking,
and
the
sweep
trigger
.
Note that
the
HP 8756A display inputs
,
SWEEP IN
and
POS
Z BLANK, come from
the
HP
5344A SWEEP
OUT
and
Z
AXIS
OUT
,
and
IF
Out
IF
In
' < 0.
10
MHl
Std Out
' "
HP S344S
Swp
HP
8756A
Microwave
Trg·
Seal" Network
Analyzer
Sou
..
"
:
.1
o
t
Synchronizer
' M
'.
1
pos
Z
Blank
Z A,ds out!f
0",
0
Sweep
In 0·10
V
Swp Out
-
0 0 0
Stop Sweep
FM Input
I
POS
Z
B181'1k
Z
AXil
In
~'!I'
.I:
Sweep
Out/In
Swp
In
0
HP
83509
SWltep 05cil1ator
p
rogramml
ng
Connector
(HP
Part
No.
8120
3545)
·This connection
is
requ ired
only in
lock
and
Roll
measuremenu.
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