Upload
sirjole7584
View
223
Download
0
Embed Size (px)
Citation preview
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
1/12
Hintsfor making
BetterNetworkAnalyzer
MeasurementsApplicatio n Note 1291-1
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
2/12
Overv iew of networkanalyzers
Network analyzers characterize
the impedance or S-parameters of
active and pas sive networks, su ch
as a mplifiers, mixers, duplexers,
filters, couplers, at tenu ators. These
component s are us ed in systems as
comm on an d low cost as a pa ger,
or in systems a s complex and
expensive as a commun icat ions
or radar system. Components can
have one port (input or outpu t) or
ma ny port s. The ability to meas ur ethe inpu t char acteristics of each
port, as well as th e tra nsfer char-
acteristics from one port to another,
gives designers the knowledge to
configure a component as p ar t of a
larger system.
Types of netw orkanalyzers
Vector network analyzers
(VNAs) are t he m ost powerful kind
of network a nalyzer an d can
meas ure from as low as 5 Hz to up
to 110 GHz. Designers , and final
test in m anu facturing, use VNAs
because t hey measure and display
the complete amplitude and phase
chara cteristics of a network. These
characteristics include S-parameters,
tra nsfer functions, ma gnitude and
phas e, stan ding wave rat ios (SWR),
insert ion loss or gain, at tenu ation,
group delay, retu rn loss, and
reflection coefficient.
VNA har dware consists of a s weep-
ing signal source (usu ally intern al),
a test set t o separate forward a nd
reverse test signals, and a multi-
chann el, phase-coherent, h ighly
sensitive receiver. In t he RF a nd
microwave bands, t ypical mea sur ed
param eters are referred to as
S-para meters, and are also com-
monly used in comput er-aided
design m odels.
Scalar network analyzersA scalar network a nalyzer (SNA)
measur es only the am plitude
portion of the S-parameters,
resulting in measur ements such as
tra nsmission gain an d loss, return
loss, and SWR. Once a passive or
active component ha s been designed
using the total measurement
capability of a VNA, an SNA ma y be
a more cost-effective mea sur ement
tool for the production line to reveal
out-of-specification componen ts.
While SNAs require an external
or intern al sweeping signa l sour ceand a signal separat ion test set,
th ey only need simple amplitu de-
only detectors, rath er th an complex
(and m ore expensive) phase-
coheren t detectors.
Network/spectrum analyzers
A network/spectrum ana lyzer
eliminates the circuit du plicat ion in
a benchtest setup of a network a nd
spectrum analyzer. Frequency
coverage ra nges from 10 Hz to
1.8 GHz. These combination
instr umen ts can be an economical
alternative in design and test of
active components like am plifiers
an d mixers where a nalysis of signal
perform ance is also needed.
This brochur e conta ins a var iety ofhints to help you un derstand and
improve your use of network
ana lyzers, and a quick summ ary
of network an alyzers and th eir
capabilities.
Contents
HINT 1. Measuring high -pow er
amplifiers
HINT 2. Comp ens ating for time
delay in cable
measurementsHINT 3. Improv ing reflection
measurements
HINT 4. Us ing frequenc y-offset
for mixer, conv erter
and tune r
measurements
HINT 5. Non insertible device
measurements
HINT 6. Aliasing in pha se or
delay format
HINT 7. Quick VNA calibration
verification
HINT 8. Make yo ur
measuremen ts real-t ime, accurate and
automated
2
RECEIVER / DETECTOR
PROCESSOR / DISPLAY
REFLECTED(A)
TRANSMITTED(B)
INCIDENT(R)
SIGNAL
SEPARATION
SOURCE
Incident
Reflected
Transmitted
DUT
Network Analyzer Block Diagram
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
3/12
The frequency-response effects ofthe a ttenua tors and couplers can
be removed or m inimized by using
the a ppropriate t ype of err or-
correction. One concern when cali-
brating with extra attenu ation is
tha t th e input levels to the r eceiver
ma y be low dur ing the calibrat ion
cycle. The power levels mu st be
significan tly a bove the n oise floor
of th e receiver for accur at e mea-
surement s. For this reason, network
analyzers tha t have a nar rowband,
tun ed-receiver a re t ypically used
for high-power applications sinceth eir n oise floor is t ypically 90
dBm, an d th ey exhibit excellent
receiver linear ity over a wide ra nge
of power levels.
Some network ana lyzers with full
two-port S-para meter capa bility
enable measu ring of the r everse
chara cteristics of th e AUT to allow
full two-port error correction. If
attenu ation is added to the output
port of th e ana lyzer, it is best t o
use a higher power in the r everse
direction t o reduce noise effects in
the measu rement of S22 and S12 .
Man y VNAs a llow un couplin g of
the test-port power to accomm odate
different levels in t he forwar d an d
reverse dir ections.
Testing high-power amplifiers cansometimes be challenging since th e
signal levels needed for t est m ay be
beyond the stimulus/response range
of th e network a nalyzer. High-
power amplifiers often require high
input levels to chara cterize them
under conditions similar to actua l
opera tion. Often th ese realistic
opera ting conditions also mea n
the output power of the am plifier
exceeds th e compr ession or bur n-
out level of th e an alyzer s r eceiver.
When you n eed an inpu t level
higher than the network analyzer s
source can pr ovide, a pr eamplifier
can be used to boost the power level
prior to th e amplifier un der test
(AUT). By using a coupler on t he
output of the pream plifier, a portion
of th e boosted input signal can be
used for th e an alyzers r eference
chann el. This configura tion rem oves
the pream plifiers frequen cy re-
sponse and dr ift errors (by ra tioing),
which yields an accurate measure-
ment of th e AUT alone.
When th e out put power of the AUT
exceeds th e input compr ession level
of th e an alyzer s r eceiver, some type
of at tenu at ion is needed to redu ce
the outpu t level. This can be
accomplished by using couplers,
att enua tors, or a combinat ion of
both. Car e must be taken to choose
components tha t can absorb th e
high power from t he AUT without
sust aining dam age. Most loads
designed for s ma ll-signal use can
only ha ndle up t o about one watt of
power. Beyond that, special loads
that can dissipate more power mu st
be used.
How to Boost and Attenuate Sign alLevels w hen Measu ring High-pow erAmplifiers
HINT
1
3
HP 8753D
Preamp
H
ACTIVE CHANNEL
RESPONSE
STIMULUS
ENTRY
I N S TR U ME N T ST A TE R C H AN N EL
R L T S
HP-IB STATUS
8753DNETWORK ANALYZER
30 KHz-3GHz
PROBE POWERFUSED
PORT2PORT1
AUT
Ref In
High-powerload
Coupler
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
4/12
Comp en sate for TimeDe lay for Better CableMeasurements
A network ana lyzer sweeps itssource frequen cy and t uned r eceiver
at th e same time to make stimulus-
response measu rements. Since the
frequen cy of a sign al coming from a
device under test (DUT) may n ot be
exactly the same as the network
ana lyzer frequency at a given
insta nt of time, this can sometimes
lead to confusing meas ur ement
resu lts. If the DUT is a long cable
with time delay T and the network
analyzer sweep rate is
df/dt, t he signa l frequency
at t he end of the cable(input to the vector net-
work ana lyzers receiver)
will lag behind th e network
ana lyzer sour ce frequen cy
by amount F=T*df/dt. If
this frequen cy shift is
appr eciable compared t o
th e network an alyzers IF
detec-tion bandwidth
(typically a few kHz), then
the measu red result will
be in er ror by t he r olloff
of the IF filter.
Figure 1 shows this effect wh enmeasur ing the transm ission
res ponse of a t welve-foot long cable
on a HP 8714C network an alyzer.
The upper tr ace shows the tr ue
response of the cable, using a
1-second sweep tim e. The lower
tra ce uses the default sweep time
of 129 msec, an d the da ta is in
err or by about 0.5 dB due to th e
frequency shift t hr ough the cable.
This sweep time is too fast for this
particular DUT.
The lower tr ace of Figure 2 showsan even more confusing resu lt
when measuring the same cable on
a H P 8753D with 100 msec sweep
time. Not only is there an err or in
the dat a, but t he size of the error
makes some sharp jumps at certain
frequencies. These frequen cies ar e
th e band-edge frequencies in th e
HP 8753D, and t he tr ace jumps
becaus e the n etwork an alyzers
sweep ra te (df/dt) changes in
different ba nds. This leads t o a
different frequen cy shift th rough
th e cable, and hence, a different
amount of error in th e data. In t his
case instea d of increasin g the sweep
time, the situ at ion can be corr ected
by removing th e R-cha nnel jump er
on the front pa nel of th e HP 8753D
and connecting a second cable of
about t he same length as the DUT
cable. This balan ces the delays in
the r eference and t est paths, so
th at th e network an alyzers rat ioed
tra nsmission measu rement does
not ha ve the frequency-shift err or.
The upper tr ace of Figure 2 shows a
measur ement of the DUT using the
same 100 msec sweep time, but with
the matching cable in R channel.
4
Start 10.000 MHz
2:Off
HP 8714C 1SEC VS 0.129SEC
1:Transmission &M Log Mag 0.5 dB/ Ref 0.00 dB
-2
-1.5
-1
-.5
.5
1
1.5
2
dB
Stop 3 000.000 MHz
1
M1
1:
Start .300 000 MHz
S21 &M Log MAG
HP 8753C 100mSEC WITH & WITHOUT EXTENSION
0.5 dB/ Ref 0.00 dB
Hld
*
PRm
Cor
CH1
Stop 3 000.000 MHz
Figure 1
Figure 2
HINT
2
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
5/12
HINT
3
DUT16 dB return loss (0.158)1 dB loss (0.891)
Analyzer port 2 match:18 dB (0.126)
0.158
Measurement uncertainty:20 * log (.158 + 0.100 + 0.010)= 11.4 dB (4.6dB)
20 * log (0.158 0.100 0.010)= 26.4 dB (+10.4 dB)
0.891*0.126*0.891 = 0.100
Directivity:40 dB (0.010)
DUT16 dB return loss (0.158)1 dB loss (0.891)
Load match:18 dB (.126)
10 dB attenuator (0.316)SWR = 1.05 (0.024)
0.158
(0.891)(0.316)(0.126)(0.316)(0.891) = 0.010
(0.891)(0.024)(0.891) = 0.019
Directivity:40 dB (.010)
Worst-case error = 0.01 + 0.01 + 0.019 = 0.039
Measurement uncertainty:-20 * log (0.158 + 0.039)= 14.1 dB (-1.9 dB)
-20 * log (0.158 - 0.039)= 18.5 dB (+2.5 dB)
P roper Termin ation Key to Improvin g Reflec tionMeasurements
Making a ccur at e reflectionmeasur e-ment s on t wo-port devices
with tr ans mission/reflection (T/R)
based analyzers (such as th e HP
8711C family of RF analyzers)
requir es a good terminat ion on the
unmeasu red port. This is especially
tr ue for low-loss, bi-directiona l
devices such as filter pa ssban ds
an d cables. T/R-based ana lyzers
only offer one-port calibra tion for
reflection meas ur e-ments, which
corr ects for err ors caused by
directivity, source ma tch a nd
frequency response, but not
load match.
One-port calibrat ion assu mes a
good termina tion at port 2 of the
device under test (th e port not
being measu red), since load m at ch
is not corrected. One way to achieve
this is by connecting a high-quality
load (a load from a calibrat ion kit ,
for exa mple) to port 2 of th e device.
This technique yields measurement
accur acy on a pa r with m ore expen-
sive S-parameter-based analyzers
tha t u se full two-port calibrat ion.
However, if port 2 of the d evice is
connected directly to th e net work
an alyzers test port, th e assum ption
of a good load termination is not
valid. In this case, measurement
accuracy can be improved consider-
ably by placing an a tt enua tor (6 to
10 dB, for example) between port 2
of the device and th e test port of the
an alyzer. This impr oves t he effective
load m atch of the a na lyzer by twice
the value of the att enuator.
Figure 1 s hows an exam ple of howthis works. Lets say we ar e meas-
ur ing a filter with 1 dB of insert ion
loss an d 16 dB of retu rn loss
(Figure 1A). Using an a na lyzer with
an 18 dB load m atch an d 40 dB
directivity would yield a worst-case
measurem ent uncer-tainty for
ret ur n loss of 4.6 dB, +10.4 dB.
This is a ra ther lar ge variation that
might cause a filter t hat didnt
meet its specifications t o pass, or a
good filter to fail. Figur e 1B sh ows
how adding a high-quality (for
exam ple, VSWR = 1.05, or 32 dB
match) 10-dB attenuator improves
the load mat ch of the ana lyzer to
29 dB [(2 x 10 + 18 dB) combined
with 32 dB]. Now our worst-case
measurem ent uncer-tainty is re-
duced t o +2.5 dB, 1.9 dB, which is
much more reasonable.
An example where one-port calibra-
tion can be used quite effectively
without an y series at tenuat ion is
when measur ing the input mat ch of
am plifiers with high-reverse isola-
tion. In t his case, th e am plifiers
isolation essentia lly eliminates t he
effect of imper fect load m at ch. Figure 1A
Figure 1B
5
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
6/12
Use Freque ncy -offse t Modefor Accu rate Meas urem en ts ofMixe rs, Con ve rters an d Tun ers
Fr equency-tr an slating devices suchas m ixers, tuner s, and converters
present unique measurement chal-
lenges since their input and output
frequencies differ. The t ra ditiona l
way to measu re t hese devices is
with br oadband diode detection.
This technique allows scalar mea -
sur ement s only, with m edium
dynamic range and moderate
measurement accuracy.
For h igher a ccur acy, vector n etwork
analyzers such a s the HP 8753D
an d 8720D offer a frequen cy-offsetmode where t he frequency of the
interna l RF source can be a rbitrar ily
offset from th e ana lyzers receivers.
Nar rowband detection can be used
with t his m ode, providing high dy-
nam ic ran ge and good measu rement
accur acy, as well as th e ability to
measure phase and group delay.
There ar e two basic ways tha tfrequency-offset mode can be used.
The simplest way is to ta ke the
output of the mixer or tu ner directly
into the reference input on the
an alyzer (See Figure 1A). This t ech-
nique offers scalar measurements
only, with u p to 35 dB of dynam ic
ra nge (beyond t ha t, th e ana lyzer s
source will not phase lock properly).
For mixers, an externa l LO must be
pr ovided. After specifying th e
measur ement setup from the front
pan el, the pr oper RF frequency
span is calculated by the an alyzerto produce the desired IF frequen-
cies, which t he r eceiver will tune t o
dur ing the sweep. The network
an alyzer will even sweep the RF
source backwar ds if necessar y to
provide the specified IF span .
For high-dynamic-range amplitude
measur ements, a reference mixer
mu st be used. (See Figure 1B.)
This mixer pr ovides a signal to the
R chann el for proper ph ase lock,
but does not affect measurements
of the DUT since it is not in th e
measur ement path . For phase or
delay measu rements, a reference
mixer mu st a lso be used. The refer-
ence mixer and t he DUT must
shar e a common LO to guarant ee
phase coherency.
When test ing mixers, either t ech-
nique requires an IF filter to rem ove
th e mixers un desired mixing
products a s well as t he RF a nd
LO leakage signals.
6
FREQ
ON off
LO
MENU
DOWNCONVERTER
|
UPCONVERTER
RF > LO
|
RF < LO
VIEWMEASURE
RETURN
1 2
Ref IN
start: 900 MHz
stop: 650 MHz
FIXED LO: 1 GHz
LO POWER: 13 dBm
start: 100 MHz
stop: 350 MHz
CH1 CONV MEAS log MAG 10 dB/ REF 10 dB
START 640.000 000 MHz STOP 660.000 000 MHz
H
ACTIVE CHANNEL
RESPONSE
STIMULUS
ENTRY
INSTRUMENTSTATE R CHANNEL
R L T S
HP-IB STATUS
8753DNETWORK ANALYZER
30 KHz -3GHz
PROBE POWERFUSED
PORT2PORT1
Ref In
10 dB
Reference Mixer
3 dB
10 dB
10 dB
Signal Generator
LowpassFilter
HP 8753D
Ref Out
IF
LO
RF
LO
DUT
HINT
4
Figure 1B
Figure 1A
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
7/12
Swap-Equal-Adapters Method
Port 1
DUTPort 1 Port 2
Port 1 Port 2AdapterA
AdapterB
Port 2
Non-insertable device
1. Transmission cal usingadapter A.
2. Reflection cal usingadapter B. Length ofadapters must be equal.
3. Measure DUT usingadapter B.DUTPort 1 Port 2
AdapterB
Increas ing the Accu racy of Noninse rt ible DeviceMeasurements
length approaches a quarterwavelength, the residual load match
can actua lly get as high as 6 dB
worse tha n th e raw load ma tch.
For a 1-GHz measurement, one
hundr edth of a wavelength means
less tha n 3 mm (about 0.12 inches).
2. Use sw ap equal adapters .
In th is method you use t wo ma tched
ada pters of the sa me electr ical
length, one with m ale/female
connectors and one that matches
the device under t est.
Suppose your instrum ent test ports
ar e both m ale, such as th e ends of a
pair of test -port cables, an d your
device has two female ports. P ut a
female-to-female thr ough adapt er,
usually on port 2, and do the tra ns-
mission portion of the calibrat ion.
After t he four t ra nsm ission
measurem ents, swap in th e male-
to-female adapt er (now you h ave
two male test ports), and do the
reflection portion of the calibration.
Now you are r eady to measu re your
device. All the a dapt ers in th e cali-
brat ion kits ar e of equal electr ical
length (even if their physical
lengths ar e different).
3. Modify the th rough -l ine-
standard. If your application is
manu factur ing test, the swap-
equal-adapt ers meth ods r equire-
ment for a dditional adapters m ay
be a dra wback. Inst ead, it is
possible to modify the calibration
kit definition t o include th e length
of th e thr ough line. If the calibrat ion
kit ha s been modified to ta ke into
account t he loss and delay of the
thr ough, then t he corr ect value for
load m at ch will be mea sur ed. Its
easy to find t hese values for t he
male-to-male th rough and the
Fu ll two-port err or corr ectionprovides th e best a ccur acy when
measur ing RF and microwave
components . But, if you h ave a non-
insertable device (for example, one
with fema le connectors on both
ports), th en its test ports cann ot be
directly connected dur ing calibra -
tion. Extra car e is needed when
ma king this thr ough connection,
especially while measu ring a device
that has poor output ma tch, such as
an am plifier or a low-loss device.
There are four general ways to
handle th e potential errors with
a t hr ough connection for a nonin-
sert able device:
1. Use a very sh ort through.
This allows you t o disregar d th e
potential er rors. When you connect
port 1 to port 2 du ring a calibrat ion,
the a nalyzer calculates th e retur n
loss of the se cond por t (th e load
mat ch) as well as the tra nsmission
ter m. When the calibrat ion kit def-
inition does not cont ain t he correct
length of the t hrough, an er ror
occurs in th e measur ement of the
load m atch. If a barr el is used to
connect port 1 t o port 2, the mea -
sur ement of the port 2 ma tch will
not have the correct phase, and the
error-correction algorithm will not
rem ove th e effects of an imper fect
port 2 impedance.
This approach will work well
enough if the t hr ough connection is
quite short. However, for a typical
network a nalyzer, short means
less than one hu ndredth of a wave-
length. If the thr ough connection is
one tenth of a wavelength (at t he
frequency of interest ), the corrected
load match is no better than t he
ra w load ma tch. As the th rough
female-to-female t hr ough. First, do
a swap-equal-adapter calibration,
ending up with both female or both
male test ports. Then simply
measur e th e noninserta ble
thr ough an d look at S 21 delay (use
th e midband value) and loss at
1 GHz. Use t his value to modify
th e calibrat ion kit.
4. Use the ad apter-removal
technique . Several HP vector
network a nalyzer m odels offer an
ada pter-rem oval technique to elim-
inate all effects of through adapters.
This technique r equires two full
two-port calibrat ions, but yields th e
most accurate measurement results.
7
HINT
5
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
8/12
HINT
61:
2:
Start 130.000 MHz Stop 150.000 MHz
1: Transmission
2: Transmission
Delay
Phase
1
51 POINT TRACE Meas1:Mkr1 140.000 MHz
1.1185
/
500 ns/
100
Ref 0 s
Ref 0.00
s
Ref = 0 seconds
Delay
Appears
Negative
2:
Start 130.000 MHz
1:
Stop 150.000 MHz
1: Transmission
2: Transmission
Delay
Phase
1201 POINT TRACE Meas1:Mkr1 140.000 MHz
1.3814
/
500 ns/
100
Ref 0 s
Ref 0.00
s
Ref = 0 seconds
Delay
Known
Positive
Figure 1
When meas ur ing a device undertest (DUT) that ha s a long electr ical
length, use care t o select approp-
riate measurement param eters.
The VNA sam ples its dat a at
discret e frequency points, t hen
connects the dots on the display
to mak e it more visually appealing.
If the pha se shift of the DUT
changes by more than 180 degrees
between adjacent frequency points,
th e display can look like th e phas e
slope is reversed! The data is un der-
sam pled and a liasing occur s. This
is analogous to filming a wagonwheel in m otion, wher e t ypically
too few frames ar e shot t o accur-
ately portr ay the m otion a nd th e
wheel appears to spin backwards.
In addition, the VNA calculat es
group delay data from phase dat a.
If the slope of the pha se is reversed,
th en th e group delay will cha nge
sign. A SAW filter ma y appear to
ha ve negative group delay clearly
not a corr ect ans wer. If you suspect
aliasing m ight be occurrin g in your
measur ements, try this simple test.
Just decrease the spacing between
frequency points a nd see if the
dat a on th e VNAs display cha nges.
Either increase the num ber of
point s, or r educe the frequency span.
Figure 1 shows a measu rement
of a S AW bandpa ss filter on a n
HP 8714C VNA, with 51 points in
th e display. The indicated gr oup
delay is negative a ph ysical im-
possibility. But if the n umber of
points increases to 201 (figure 2),
it becomes is clear th at the VNA
settings created a n a liasing
problem.
Figure 2
8
Che ck for Aliasing in P has eor Delay Format
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
9/12
To verify transm ission (S 21 )measurements:
1. Connect a thr ough cable from
port 1 to port 2. The magnit ude of
S21 sh ould be close to 0 dB (with in a
few tenth s of a dB).
2. To verify S21 isolation, connect
two loads : one on port 1 an d one on
port 2. Measur e the magnitude of
S21 and verify that it is less than
th e specified isolation (typically
less tha n 80 dB).
To get a more accurat e ra nge ofexpected values for t hese mea sur e-
ment s, consult th e ana lyzer s
specifications. You migh t a lso
consider doing these verifications
immediat ely after a calibrat ion to
verify the quality of the calibrat ion.
If youve ever mea sur ed a de vicean d the mea sur ement s didnt look
quite right, or you were unsu re
about a par ticular an alyzers accur-
acy or per form ance, here a re a few
quick check met hods you can u se
to verify an inst ru ment s calibration
or performan ce. All you n eed ar e
a few calibration standards.
Verifying re flections
measurements
To verify reflection (S11) measure-
ment s on the source port (port 1)
per form one or mor e of th e follow-ing steps:
1. For a quick first check, leave port
1 open and verify tha t th e magni-
tu de of S11 is near 0 dB (within
about 1 dB).
2. Connect a load calibrat ion
standa rd to port 1. The magnitude
of S11 should be less than the
specified calibrated directivity of
th e ana lyzer (typically less th an
30 dB).
3. Connect either an open or sh ort
circuit calibration standard to
port 1. The ma gnitude of S11 should
be close to 0 dB (with in a few tenth s
of a dB).
Quic k CalibrationVerification
HINT
7
9
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
10/12
Make your Measu remen tsReal-tim e, Accurate andAutomated
Tunin g and testin g RF devices ina pr oduction environment often
requires s peed and a ccur acy from
a n etwork an alyzer. However, at
fast sweep speeds an ana lyzer s
optimum a ccur acy may be unavail-
able. By using save/recall register s
you can get both fast an d accur at e
measurements.
Using save/recall registers
For example, when adjusting the
passba nd an d stopband r ejection of
a ban dpass filter, first set up t he
basic measur ement on t he an alyzer(the start and stop frequencies,
power level, etc.).
Then increase the IF bandwidth
and r educe the nu mber of data
points (to speed up the t ra ce) and
save this as State 1.
Next, reduce the IF bandwidth and
increase th e num ber of data points
(to get a more accurate measure-
ment).
Add the final limit lines a nd sa veth is as Sta te 2. Now, by alter nat ely
recalling these two stat es you can
adjust the filter in r eal time and
th en a ccur ately verify its specifi-
cations.
Hands-free toggl ing betwe en
instrument s tates
Some network ana lyzers like the
HP 8711C family include a BNC
input tha t can be connected to a
footswitch for toggling between t wo
(or more) stat es.
Instrument automation
For m ore complex testing su ch as
fina l test, an an alyzer with IBASIC
program ming capability (HP 8711C
family, HP E5100, and H P 8751)
provides complex computa tion an d
contr ol so you can easily automa te
measurements.
Using t he IBASIC pr ogra m doesnt
require programming experience.
You can ea sily cust omize each tes t
or combinat ion of tests an d activate
th em by a softkey or footswitch t o
aut omatically set up system pa ra-
meter s for ea ch device you test.
HINT
8
10
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
11/12
Guide to HP Ne tw ork Analyzers
HP E5100A/B Hig h-Speed
Network Analyzers
The HP E5100A/B network ana ly-
zers ha ve been designed resonator
and filter ma nufacturers who needextra-high t hroughput. Numer ous
options ta ilor t hese an alyzer with a
minimum investment. The frequency
ra nge is from 10 kHz to 300 MHz.
With 0.04 ms/point m easur ement
speed, waveform a nalysis capabil-
ity, very low noise circuitr y, an d
IBASIC aut omation capability, the
HP E5100 will improve your ma nu-
facturing productivity.
HP 8711C RF
Network Analyzers
The H P 8711C, 8712C, 8713C,
and 8714C network analyzers are
optimized for economical, high -volume component m an ufacturin g.
They offer gr eat flexibility with
th eir m any options, including AM
group dela y, 50 or 75 ohm syst em
impedan ce, an d intern al 60-dB step
at tenu at or. Some m odels also offer
measur ements of amplitude, phase,
an d group delay. The h igh-speed
CPU, large VGA-compatible display,
IBASIC automat ion, an d LAN
inter connectivity round out th is
familys capa bilities. Frequ ency
ra nge is 300 kHz to 1.3 or 3.0 GHz.
HP 4396B Ne twork/Spectrum/
Impedence Analyzer
The HP 4396B provides excellent
RF vector network, spectr um , and
optional impedance measurementsfor la b an d pr oduction applications.
Measure an d evaluate, with one
instrum ent, the gain, phase, group
delay, distortion, spur ious, car rier-
to-noise ra tio, and n oise of your
components an d circuits. As a
vector net work a nalyzer, the
HP 4396B opera tes from 100 kHz
to 1.8 GHz with 1 MHz resolution
for net work a nalyzer mea surement s.
When combined with a t est set,
th e HP 4396B provides reflection
measur ements, such as r eturn loss,
and SWR, and S-para meters.
HP 8751A Precisio n
Network Analyzer
For highly accura te measu rements
at lower frequencies (5 Hz to 500
MHz), the H P 8751A network
ana lyzer pr ovides 0.001 Hz, and
10 ps resolution using full two-port
calibra tions. Th e 8751A also offers
unique features such as conjugate
ma tching ana lysis. With IBASIC
aut omation and built-in disk drive,
the HP 8751A is also ready for
manufacturing applications.
11
8/14/2019 HP-AN1291!1!8 Hints for Making Better Network Analyzer Measurements
12/12
For more information, visit our w ebsi te at Access HP:http://www.tmo.hp.com/For more informat ion about
Hewlett-Packard test and measure-ment products , appl i cat ions ,serv i ce s , and for a current sa l e sof f i ce l i s t ing , v i s i t our web s i t e ,http :/ /w ww.hp .com/go/tmdir . Youcan also contact one of the followingc e n t e r s a n d a s k f o r a t e s t a n dmeasurement sales representative .
United States:Hewlett-Packard CompanyTest and Measu rement Ca ll CenterP.O. Box 4026En glewood, CO 80155-40261 800 452 4844
Canada:Hewlett-Packard Canada Ltd.5150 Spectru m WayMississauga, OntarioL4W 5G1(905) 206 4725
Europe:Hewlett-PackardEuropean Marketing CentreP.O. Box 9991180 AZ AmstelveenThe Netherlands(31 20) 547 9900
Japan:Hewlett-Packard J apan Ltd.Measurement Assistance Center9-1, Takakura-Cho, Hachioji-Shi,
Tokyo 192, J apa nTel: (81-426) 56-7832Fax: (81-426) 56-7840
Latin America:Hewlett-PackardLatin American Region Headquar ters5200 Blue La goon Dr ive, 9th F loorMiam i, Florida 33126, U.S.A.(305) 267 4245/4220
Australia/New Zealand:Hewlett-Packard Australia Ltd.31-41 Joseph Str eetBlackburn, Victoria 3130, Australia1 800 629 485
Asia Pacific:
Hewlett-Packard Asia Pacific Ltd.17-21/F Sh ell Tower, Times Squ ar e,1 Matheson Str eet, Causeway Bay,Hong KongTel: (852) 2599 7777Fa x: (852) 2506 9285
Data Subject to ChangeCopyrigh t 1997Hewlett-Packard CompanyPrinte d in U.S.A. 6/975965-8166E
HP 8510C Microwa ve
Network Analyzer
Since its intr oduction in 1985, theHP 8510 series of microwave net-
work a nalyzers ha ve set the
standard for performance. These
ana lyzers provide a complete solu-
tion for char acterizing the linear
behavior of active or pass ive net-
works from 45 MH z to 50 GHz.
On-wafer, millimeter -wave m easur e-
ments, pulsed-RF m easurements,
broadband bias, calibra tion and
cont rol the H P 8510 does it all.
With options for electr onic
calibration, frequency to 110 GHz,
frequency converter s for m ixer
measurem ents and m ultiple-test-
set support , the HP 8510 fam ily
meets every need.
HP 8752C and 8753D RF
Network Analyzers
A rich set of measur ementcapabilities with excellent perfor-
man ce and accura cy make
th e HP 8752/8753 fam ily the
standa rd by which other analyzers
ar e measur ed. A fully integra ted
S-parameter test set, exceptional
dynam ic ra nge, har monic and offset
frequency mea surement capabilties,
plus thr ee independent, tuned
receivers p rovide afforda ble excel-
lence. Options for time domain
(including TDR functionality),
6 GHz frequency ran ge, high-
sta bility source for SAW meas ur e-
ments, 75 ohms a nd ma ny others
make t he HP 8753D a very versatile
network analyzer.
HP 8720D Microwa ve
Network Analyzers
For m icrowave frequencies, the
HP 8720D fam ily of network a naly-
zers offers excellent perform an ce at
an afforda ble price. Compa ct and
easy to use, this family has th e
same contr ol and interface as the
HP 8753D RF network a nalyzer,
but provides frequen cy-response
covera ge from 50 MHz t o 13.5, 20,
or 40 GHz. Options include four-
sam pler architectur e for full
TRL/LRL calibr at ions for on-wafer
and other noncoaxial measurements,
a h igh-power test set, direct sampler
access, an d time-doma in. DX models
come preconfigured with options
for non-coaxial app licat ions a t a
value pr ice.
HP Ne tw ork Analyzers(contd)