MMS to X-Series - bei der Computer Controls AG

Herzlich Willkommen!
Netzwerkanalyse
Grundlagen und Anwendungsüberblick
Tomas Lange (Agilent)
2013
Page 1
Agenda
 Arten der Leistungsmessung über der Frequenz
• Physikalische Grundlagen der HF Übertragung
• Charakterisierung der HF-Übertragung
• Messbare Parameter
• Aufbau des Network Analyzers
• Modellüberblick
• Applikationsbeispiele
Page 2
‘Netzwerkanalyse’ ist NICHT .…
Router
Bridge
Repeater
Hub
Your IEEE 802.3 X.25 ISDN
switched-packet data stream
is running at 147 MBPS with
-9
a BER of 1.523 X 10 . . .
… es IST: HF Baugruppen & Komponenten Test !!!
Page 3
Messmöglichkeiten: Leistung über Frequenz
• Misst Amplitude über Zeit
• Berechnet f (FFT) mit sehr
begrenzter Ampl.auflösung
• f-Auflösung <=> Speichertiefe
•
•
•
•
Oszilloskop
Power Meter
Network Analyzer
• Kann messen was er erzeugt
-> hochgenaue Relativmessung
• Nur schmalbandige Messung
• Keine Signal-Inhaltsanalyse
• Phase !
Page 4
Nur breitbandige Messung
Keine Selektivität
Eingeschränkte Dynamik (Ampl.)
Keine Phase
Spectrum Analyzer
•
•
•
•
•
Kann auch Summenleistung in Band
Spektrum & Signal(-inhalts)analyse
Grosse Dynamik
Exzellente Selektivität
Keine Phase
Agenda
• Arten der Leistungsmessung über der Frequenz
 Physikalische Grundlagen der HF Übertragung
• Charakterisierung der HF-Übertragung
• Messbare Parameter
• Aufbau des Network Analyzers
• Modellüberblick
• Applikationsbeispiele
Page 5
Analogie des Lichts zur HF Energie
Incident
Reflected
Transmitted
Strahlen Optik
DUT
HF
Page 6
Warum überhaupt Komponenten messen?
Die “building blocks” müssen Spezifikationen einhalten, damit ein komplexes
HF-System funktioniert
Störungsfreie Übertragung von Nutz-/Kommunikationssignalen
Überprüfung grundlegender Eigneschaften
• linear: constant amplitude, linear phase / constant group delay
7
• nonlinear: harmonics, intermodulation,Pagecompression,
AM-to-PM conversion
Impedanzanpassung (Effizienz!)
Einhaltung von EMV Vorgaben
KPWR
Page 7
FM 97
Signalübetragung - Grundlagen
Niedere Frequenzen



+
I
Wellenlänge >> Kabellänge
Strom (I) läuft entlang der Leitung , effiziente Übertragung bei
niedrigem ohmschen Widerstand, sonst keine speziellen
Anforderungen
Gemessene Spannung und Strom nicht direkt ortsabhängig
Hohe Frequenzen




Page 8
Wellenlänge » oder << Länge des Ausbreitungsmediums
Effiziente Übertragung bedarf “Leitung” mit ganz speziellen
Eigenschaften
Impedanzanpassung (Zo) ist sehr wichtig für geringe Reflexion und
maximale Leistungsübertragung
Die gemessene Spannung (Hüllkurve) schwankt stark mit dem Ort
-
Transmission line: Zo (charakteristische Impedanz)
Zo bestimmt Beziehung zwischen Strom- und Spannungswelle
Zo ist eine Funktion der physikalischen Dimensionen und r
Zo ist normalerweise rein real, kein Imaginärteil (oft 50 oder 75 Ohm)
1.5
attenuation is
lowest at 77 ohms
1.4
1.3
normalized values
1.2
1.1
50 ohm standard
1.0
0.9
0.8
0.7
power handling capacity
peaks at 30 ohms
0.6
0.5
10
20
30
40
50
60 70 80 90 100
characteristic impedance
for coaxial airlines (ohms)
Page 9
Transmission Line Terminated with Zo
Zs = Zo
Zo = characteristic impedance
of transmission line
Zo
Vinc
Vrefl = 0! (all the incident power
is absorbed in the load)
For reflection, a transmission line terminated in Zo
behaves like an infinitely long transmission line
Page 10
Transmission Line Terminated with Short, Open
Zs = Zo
Vinc
Vrefl
In-phase (0o) for open,
out-of-phase (180o) for short
For reflection, a transmission line terminated in a
short or open reflects all power back to source
Page 11
Transmission Line Terminated with 25 W
Zs = Zo
ZL = 25 W
Vinc
Vrefl
Standing wave pattern does not go to
zero as with short or open
Page 12
Agenda
•
Arten der Leistungsmessung über der Frequenz
• Physikalische Grundlagen der HF Übertragung
 Charakterisierung der HF-Übertragung
• Messbare Parameter
• Aufbau des Network Analyzers
• Modellüberblick
• Applikationsbeispiele
Page 13
Charakterisierung der HF Übertragung
Incident
Transmitted
R
B
Reflected
A
TRANSMISSION
REFLECTION
Reflected
Incident
=
(V)S
WR
S-Parameters
S11, S22
Page 14
A
Transmitted
R
Incident
Return
Loss
Reflection
Coefficient
G, r
Impedance,
Admittance
R+jX,
G+jB
=
B
R
Group
Delay
Gain / Loss
S-Parameters
S21, S12
Transmission
Coefficient
T,t
Insertion
Phase
Reflection Parameters
Vreflected
Reflection
=
=
Coefficient G
Vincident
Return loss = -20 log(r),
Emax
Emin
r
r
F
=
Z L + ZO
G
Voltage Standing Wave Ratio
Emax
VSWR =
Emin
=
1+r
1-r
Full reflection
(ZL = open, short)
No reflection
(ZL = Zo)
Page 15
=
ZL - ZO
0
r
1
 dB
RL
0 dB
1
VSWR

Smith Chart Review
.
+jX
Polar plane
90
o
1.0
.8
.6
0
+R
.4

+ 180 o
-
o
.2
0

0
-jX
-90 o
Rectilinear impedance
plane
Constant X
Constant R
Z L = Zo
Smith Chart maps
rectilinear impedance
plane onto polar plane
G=
0
ZL =
Z L = 0 (short)
G= 1
±180
G =1
O
Smith chart
Page 16
(open)
0
O
Transmission Parameters
V Incident
V Transmitted
DUT
Transmission Coefficient =
T
=
V
Insertion Loss (dB) = - 20 Log
V
Gain (dB) = 20 Log
V
Page 17
V
Trans
Inc
V Transmitted
V Incident
Trans
=
t
= - 20 log
Inc
= 20 log
t
t
Verhalten linearer und nichtlinearer Systeme
A * Sin 360o * f (t - to)
A
Linear behavior:

Time
to
Sin 360o * f * t
A
Time
f
1
DUT
Input

phase shift =
to * 360o * f
input and output frequencies are
the same (no additional
frequencies created)
output frequency only undergoes
magnitude and phase change
Frequency
Output
Nonlinear behavior:
f
1

Frequency
Time

f
Page 18
1
Frequency
output frequency may
undergo frequency shift
(e.g. with mixers)
additional frequencies
created (harmonics,
intermodulation)
Voraussetzung für unverzerrte Übertragung
LINEARITÄT
Linear phase over
bandwidth of
interest
Constant amplitude over
bandwidth of interest
Phase
Magnitude
Frequency
Frequency
Page 19
Gruppenlaufzeit (Group Delay, GD) statt Phase
Frequencyw
tg
Group delay ripple
Dw
to

Phase
D
Frequency
Group Delay (tg) =
-d 
dw

w

=
-1
360 o
*
d
df
group-delay ripple indicates phase distortion

average delay indicates electrical length of DUT

aperture of measurement is very important
in radians
in radians/sec
in degrees
f in Hertz (w = 2 p f)
Page 20

Phase
Phase
Weitere Gründe für GD statt Phasenmessung
f
f
-d 
dw
Group
Delay
Group
Delay
-d 
dw
f
Same p-p phase ripple can result in different group delay
Page 21
f
Characterizing Unknown Devices
Using parameters (H, Y, Z, S) to characterize devices:




gives linear behavioral model of our device
measure parameters (e.g. voltage and current) versus frequency under
various source and load conditions (e.g. short and open circuits)
compute device parameters from measured data
predict circuit performance under any source and load conditions
H-parameters
V1 = h11I1 + h12V2
I2 = h21I1 + h22V2
Page 22
Y-parameters
I1 = y11V1 + y12V2
I2 = y21V1 + y22V2
Z-parameters
V1 = z11I1 + z12I2
V2 = z21I1 + z22I2
h11 = V1
I1
V2=0
(requires short circuit)
h12 = V1
V2
I1=0
(requires open circuit)
Warum gerade S-Parameter messen?
S 21
Incident
Transmitted
a1
b2
S 11
DUT
Reflected
Port 2
Port 1
b1
S 22
Reflected
a2
Transmitted
Incident
S 12
b 1 = S 11 a 1 + S 12 a 2
b 2 = S 21 a 1 + S 22 a 2
S 11 =
S 21 =
Page 23
Reflected
Incident
Transmitted
Incident
b1
= a
1
b
a2 = 0
2
= a
1
a2 = 0
S 22 =
S 12 =
Reflected
Incident
Transmitted
Incident
b2
= a
2
b
a1 = 0
1
= a
2
a1 = 0
Equating S-Parameters with Common
Measurement Terms
S11 = forward reflection coefficient (input match)
S22 = reverse reflection coefficient (output match)
S21 = forward transmission coefficient (gain or loss)
S12 = reverse transmission coefficient (isolation)
Remember, S-parameters are inherently
complex, linear quantities -- however, we
often express them in a log-magnitude format
Page 24
Agenda
•
Arten der Leistungsmessung über der Frequenz
• Physikalische Grundlagen der HF Übertragung
 Charakterisierung der HF-Übertragung
• Messbare Parameter
• Aufbau des Network Analyzers
• Modellüberblick
• Applikationsbeispiele
Page 25
Vereinfachtes Network Analyzer Blockschaltbild
Incident
Transmitted
DUT
SOURCE
Reflected
SIGNAL
SEPARATION
INCIDENT
(R)
REFLECTED
TRANSMITTED
(A)
(B)
RECEIVER / DETECTOR
PROCESSOR / DISPLAY
Page 26
Signal Separation
Incident
Transmitted
DUT
Reflected
SOURCE
SIGNAL
SEPARATION
INCIDENT (R)
REFLECTED
(A)
TRANSMITTED
(B)
RECEIVER / DETECTOR
PROCESSOR / DISPLAY
•
•
measure incident signal for reference
separate incident and reflected signals
splitter
bridge
directional
coupler
Page 27
Detector
Test Port
Directivity
Directivity is a measure of how well a
coupler can separate signals moving
in opposite directions
(undesired leakage signal)
(desired reflected signal)
Test port
Directional Coupler
Page 28
Detector Types
Incident
Transmitted
DUT
Reflected
SOURCE
Diode
Scalar broadband
(no phase
information)
SIGNAL
SEPARATION
INCIDENT (R)
REFLECTED
(A)
TRANSMITTED
(B)
RECEIVER / DETECTOR
PROCESSOR / DISPLAY
DC
RF
AC
Tuned Receiver
RF
IF = F
LO  F RF
ADC / DSP
IF Filter
LO
Page 29
Vector
(magnitude and
phase)
Comparison of Receiver Techniques
Broadband
(diode) detection
Narrowband
(tuned-receiver) detection
0 dB
0 dB
-50 dB
-50 dB
-100 dB
-100 dB
-60 dBm Sensitivity
higher noise floor
 false responses

< -100 dBm Sensitivity
high dynamic range
 harmonic immunity

Dynamic range = maximum receiver power - receiver noise floor
Page 30
Network Analyzer mit eingebautem Test Set –
verschiedene Optionen
S-Parameter Test Set
Transmission/Reflection Test Set
Source
Source
Transfer switch
R
R
B
A
Port 1
Port 2
Fwd



Page 31
Port 2
Port 1
Fwd
DUT
HF kommt immer aus Port 1
Port 2 ist immer nur Empfänger
Einfache Response CAL
B
A



DUT
Rev
HF kommt aus Port 1 oder Port 2
Kann vorwärts und rückwärts messen
Full-two-port CAL
Systematische Messfehler
R
Directivity A
(Richtschärfe)
Crosstalk
(Übersprechen)
B
DUT
Frequenzgang

reflection tracking (A/R = Reflexion)

transmission tracking (B/R = Übetragung)
Source Mismatch
(Quellenanpassung)
Load Mismatch
(Lastanpassung)
Sechs Fehlerterme für “vorwärts”und ebensoviele für
“rückwärts” -12 error terms für Prüflinge mit 2 Toren
Page 32
Types of Error Correction

response (normalization)
simple to perform
only corrects for tracking errors
thru
stores reference trace in memory,
then does data divided by memory
vector
requires more standards
requires an analyzer that can measure phase
accounts for all major sources of systematic error







SHORT
S11a
S11 m
Page 33
thru
OPEN
LOAD
Was ist „Vector-Error Correction“?

Prozess zur Characterisierung systematischer Fehlerterme
Messung bekannter Standards
Korrektur der gemessenen Effekte von nachfolgenden
Messungen
1-port Calibration (bei der Reflexionsmessung = “CAL light”)
nur 3 systematische Fehlerterme werden erfasst:
directivity, source match, and reflection tracking
Full 2-port calibration (für Reflexions- und
Transmissionsmessung)
12 systematische Fehlerterme erfasst
Bedarf12 Messungen an vier bekannten Standards (“SOLT” =
short, open, load, through)
Standards werden in einer “cal kit definition” Datei abgelegt
Network Analyzer kennen die Definition der käuflichen (Agilent)
CAL-Kits
Bei der Messung muss auch die richtige Definition benutzt
werden!
Andere Standards lassen sich als “User-defined” Cal-Kit
abspeichern












Page 34
Two-Port Error Correction
Reverse model
Forward model
Port 1
Port 2
E RT'
Port 1
EX
Port 2
S21
a1
a1
ED
S21A
ES
S11A
b1
E RT
S22
S 12
ETT
A
EL
b2
EL' = rev load match
ETT' = rev transmission tracking
EX' = rev isolation
Page 35
A
E S'
A
ED'
a2
S12 A
E TT'
EX'
E D' = rev directivity
E S' = rev source match
E RT' = rev reflection tracking

b1
b2
A
S22
A
EL = fwd load match
ETT = fwd transmission tracking
EX = fwd isolation

S11
a2
ED = fwd directivity
E S = fwd source match
ERT = fwd reflection tracking

E L'
Jeder korrigierte S-Parameter ist eine
Funktion von allen 4 gemessenen SParametern
Analyzer muss abwechslend Vorwärtsund Rückwärts-Betrieb machen
Die Lösung des Gleichungssystems
übernimmt der Analyzer!!!
S11a =
S
- ED
S
- ED '
S
- E X S12 m - E X '
( 11m
)(1  22m
E S ' ) - E L ( 21m
)(
)
E RT
E RT '
E TT
E TT '
S
S
S
- E D'
- ED '
- E X S12 m - E X '
(1  11m
E S )(1  22m
E S ' ) - E L ' E L ( 21m
)(
)
E RT
E RT '
E TT
ETT '
(
S21a =
S12a =
E TT
)(1 
S22 m - E D '
E RT '
( E S '- E L ))
S
S
S
- ED
- ED'
- E X S12 m - E X '
(1  11m
E S )(1  22m
E S ' ) - E L ' E L ( 21m
)(
)
E RT
E RT '
E TT
ETT '
S
- EX '
S
- ED
( 12m
)(1  11m
( E S - E L ' ))
E TT '
E RT
S
- ED
S
- ED'
S
- E X S12m - E X '
(1  11m
E S )(1  22m
E S ' ) - E L ' E L ( 21m
)(
)
E RT
E RT '
E TT
E TT '
(
S22a =
S21m - E X
S 22m - E D '
E RT '
)( 1 
S11m - E D
S 21m - E X S12m - E X '
ES ) - E L ' (
)(
)
E RT
E TT
E TT '
S
- ED
S
- ED'
S
- E X S12m - E X '
(1  11m
E S )(1  22m
E S ' ) - E L ' E L ( 21m
)(
)
E RT
E RT '
E TT
ETT '
Calculating Measurement Uncertainty After a TwoPort Calibration
Corrected error terms:
DUT
1 dB loss (0.891)
16 dB RL (0.158)
(8753ES 1.3-3 GHz Type-N)
Directivity
Source match
Load match
Refl. tracking
Trans. tracking
Isolation
=
=
=
=
=
=
47 dB
36 dB
47 dB
.019 dB
.026 dB
100 dB
Reflection uncertainty
S11m = S11a  ( E D  S11a E S  S 21a S12 a E L  S11a (1 - E RT ))
2
= 0158
.
 (.0045  0158
. 2 *.0158  0.8912 *.0045  0158
. *.0022)
= 0.158 ± .0088 = 16 dB +0.53 dB, -0.44 dB (worst-case)
Transmission uncertainty
S 21m = S 21a  S 21a ( E I / S 21a  S11a E S  S 21a S12 a E S E L  S 22 a E L  (1 - E TT ))
= 0.891  0.891(10 -6 / 0.891  0158
. *.0158  0.8912 *.0158*.0045  0158
. *.0045.003)
= 0.891 ± .0056 = 1 dB ±0.05 dB (worst-case)
Page 36
Comparison of Measurement Examples
Reflection
Calibration type
One-port
One-port + attenuator
Two-port
Measurement uncertainty
-4.6/10.4 dB
-1.9/2.5 dB
-0.44/0.53 dB
Transmission
Calibration type
Response
Enhanced response
Enh. response + attenuator
Two port
Page 37
Calibration uncertainty
0.22 dB
0.02 dB
0.01 dB
-----
Measurement uncertainty
0.60/-0.65 dB
0.22 dB
0.08 dB
Total uncertainty
0.82/-0.87 dB
0.24 dB
0.09 dB
0.05 dB
Calibration Summary
Reflection
Test Set (cal type)
T/R
S-parameter
(one-port)

Reflection tracking

Directivity

Source match

Load match
SHORT
(two-port)
OPEN
LOAD
Test Set (cal type)
T/R
Transmission
(response, isolation)(two-port)
error can be corrected

Transmission Tracking

Crosstalk

Source match

Load match
error cannot be corrected
*
Page 38
enhanced response cal corrects
for source match during
transmission measurements
S-parameter
(
* )
ECal: Electronic Calibration
•
•
•
•
•
Variety of modules cover low kHz to high GHz
2 and 4-port versions available
Choose from six connector types (50 W and 75 W)
Mix and match connectors (3.5mm, Type-N, 7/16)
Single-connection
reduces calibration time
makes calibrations easy to perform
minimizes wear on cables and standards
eliminates operator errors
Highly repeatable temperature-compensated
terminations provide excellent accuracy

sa
85093A
Electronic Calibration Module
30 kHz - 6 GHz



•
Microwave modules use a
transmission line shunted by PINdiode switches in various
combinations
Page 39
Agenda
•
Arten der Leistungsmessung über der Frequenz
• Physikalische Grundlagen der HF Übertragung
 Charakterisierung der HF-Übertragung
• Messbare Parameter
• Aufbau des Network Analyzers
• Modellüberblick
• Applikationsbeispiele
Page 40
Agilent Network Analyzer Overview
Test
PNA-X, NVNA
Industry-leading performance
10 MHz to 13.5, 26.5, 43.5, 50 GHz
Banded mm-wave to 2 THz
Accessories
PNA
Performance VNA
10 MHz to 20, 40, 50, 67, 110 GHz
Banded mm-wave to 2 THz
PNA-L
World’s most capable value VNA
300 kHz to 6, 13.5, 20 GHz
10 MHz to 40, 50 GHz
ENA
World’s most popular
midrange VNA
9 kHz to 4.5, 8.5 GHz
300 kHz to 20.0 GHz
FieldFox
RF Analyzer
5 Hz to 26.5 GHz
ENA-L
Economy VNA
5 Hz/300 kHz to 1.5/3.0 GHz
Fokus heute
Page 41
PNA-X receiver
8530A replacement
Mm-wave
solutions
Up to 2 THz
Wer braucht welchen Network Analyzer (NWA)?
Wer braucht einen Spektrum Analysator?
– im Prinzip jedes Elektronik-Labor
Wer braucht einen Network Analyzer?
– jeder, der HF-Übertragungs- oder Sperreigenschaften erwartet von ...
• Einzelnen Bauteilen (Drosseln, Kondensatoren, Piezo‘s…)
• Baugruppen (OP-Verstärker, Filter, Antennen, Kabel …)
• Geräten/Einschüben (DC-Supplies, Wandler, Schirmdämpfung v. Gehäusen …)
• Materialien (Induktionskerne, Substrate, Dielektrika …)
• Usw.
Alles aber ausschließlich << 1 MHz ??  Wir haben auch LCR Meter !!!
Page 42
Low
Integration
High
What Types of Devices are Tested?
Duplexers
Diplexers
Filters
Couplers
Bridges
Splitters, dividers
Combiners
Isolators
Circulators
Attenuators
Adapters
Opens, shorts, loads
Delay lines
Cables
Transmission lines
Waveguide
Resonators
Dielectrics
R, L, C's
Passive
Page 43
RFICs
MMICs
T/R modules
Transceivers
Receivers
Tuners
Converters
VCAs
Amplifiers
Antennas
Switches
Multiplexers
Mixers
Samplers
Multipliers
Diodes
Device type
VCOs
VTFs
Oscillators
Modulators
VCAtten’s
Transistors
Active
Agenda
•
Arten der Leistungsmessung über der Frequenz
• Physikalische Grundlagen der HF Übertragung
•
Charakterisierung der HF-Übertragung
• Messbare Parameter
• Aufbau des Network Analyzers
• Modellüberblick
 Applikationsbeispiele
Page 44
Frequency Sweep - Filter Test
CH1 S 21
log MAG
10 dB/
REF 0 dB
CH1 S11
log MAG
5 dB/
REF 0 dB
Cor
Stopband
rejection
69.1 dB
START .300 000 MHz
STOP 400.000 000 MHz
CH1 S21
SPAN 50.000 MHz
CENTER 200.000 MHz
log MAG
1 dB/
REF 0 dB
Return loss
Cor
1
2
ref
Insertion loss
Cor
m1:
4.000 000 GHz 0.16 dB
m2-ref: 2.145 234 GHz
0.00 dB
x2 1
START 2 000.000 MHz
Page 45
2
STOP 6 000.000 MHz
Cable Loss Measurement Techniques
Traditional 2-Port
Loss Measurement
Novel 1-Port
Loss Measurement
Power Sensor-Based
Loss Measurement
USB
Cable
Open or Short
Power
Sensor
Cable Loss Measurement Examples
2-Port and 1-Port Cable Loss
Open or
Short
Output Power (dBm)
Power Sweeps - Compression
Saturated output
power
Compression
region
Linear region
(slope = small-signal gain)
Input Power (dBm)
Page 48
Power Sweep - Gain Compression
CH1 S21
1og MAG
1 dB/ REF 32 dB
30.991 dB
12.3 dBm
1 dB
compression:
1
0
START -10 dBm
Page 49
CW 902.7 MHz
STOP 15 dBm
input power
resulting in 1 dB
drop in gain
AM to PM Conversion
Measure of phase deviation caused by amplitude variations
Power sweep
Amplitude

AM
(dB)
Mag(Ami
n)

DUT
AM can be undesired supply
ripple, fading, thermal
AM can be desired:
modulation (e.g. QAM)
PM
(deg)
Test Stimulus
Q
Time
Amplitude
AM
(dB)
Mag(AMout)
AM - PM Conversion =
Mag(Pmout)
Mag(Amin)
(deg/dB)
PM
(deg)
Mag(Pmout
)
Output Response
Page 50
Time
I
AM to PM conversion
can cause bit errors
Antenna to Antenna Isolation
Isolation
Antenna
#2
Antenna
#1
Insertion Loss
(2-Port)
Copyright J M Briscoe and licensed for reuse
under the Creative Commons License.
FieldFox
Messungen an einem selbst gebauten Shunt (1 mOhm Widerstand)
2-resistor-type
power splitter
1 mOhm DUT
Messung an den S-Parameter Ports (50Ω)
Braucht Spulenkern zur Messung genau wie bei
Messungen an Prüflingen mit sehr großer
Dämpfung!
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Messung an den Gain-Phase
Ports (1 MOhm Eingang)
Messergebnisse am Shunt (Vergleich)
CH1: S-param. test ports with core
20*Log(|Z|)
CH:2 Gain-phase test ports without core
Source=10 dBm
IFBW=Auto / 10 Hz-limit
20*Log(|Z|)
Source=10 dBm
Port-R: Zin=50 ohm, ATT=20 dB
Port-T: Zin=50 ohm, ATT=0 dB
IFBW=Auto / 10 Hz-limit
10 dB/div
|Z|, linear scale
|Z|, linear scale
500 uohm/div
Beide Messungen ergeben korrekte Ergebnisse. Bei ganz tiefen Frequenzen ist die Gain-Phase Messung allerdings
überlegen. Die Gain-phase Test Ports ermöglichen eine Messung auch von mOhm-Prüflingen ohne die Verwendung von
Spulenkernen.
Bei der S-Parameter Messung ist das Ergebnis sehr abhängig vom richtigen Aufbau und der Anzahl der Windungen und
damit viel schwerer reproduzierbar.
Page 53
Universelle Anwendungen in F&E
(Automobil, Medizin, A&D, Kommuniksation, Industrielektronik etc)
LF-to-RF network meas. needs
in electronic equipment.
Excellent
RF performance
Wireless Interfaces
5 Hz to 3 GHz coverage
(Zigbee, Bluetooth, HF/UHF RFIDs, etc)
S-parameters
MHz to GHz range
Wide dynamic range at LF
DC-biased measurement
Transceivers

Sensor signals

Antennas
Low/mid speed data bus
(CAN, FlexRay, etc)
A/D
LF amplifiers
Freq. responses,
CMRR, & PSRR
near-DC to 100 MHz
Filters
Oscillator
circuits

MPUs/
MCUs
Freq. resp.(loop gain)
MHz range
DC-DC
Transceivers
 Wide dynamic range
Freq. resp. & impedance
100 kHz to MHz range
at MHz range
Wide dynamic range at LF
(POL/VRM)
Loop gain,
milliohm-impedance, & S21
near-DC to GHz
DC-DC converters
5 Hz to 3 GHz in single sweep
PDNs (Power Delivery Networks)
CMRR = Gleichtaktunterdrückung, PSRR = Netzstörunterdrückungsverhältnis (power supply rejection ratio)
Page 54
Weitere Spezialfälle
• Adaption an Prüfling erforderlich
• Symmetrische Messungen => mit Balun‘s oder MehrportNWA mit Superposition und Fixture Simulator
• Impedanzmessungen (Spezialfall einer Reflexionsmessung)
• Harmonische messen => Einsatz des NWA als
Direktempfänger (ohne Quelle, quasi als
Spektrumanalysator)
• Nichtlineare Netzwerkanalyase => X-Parameter
Page 55
Adaption an Prüfling: Adapterlösungen
reflection from
adapter
leakage signal
desired signal
r
measured = Directivity +
r
adapter +
r
DUT
Coupler directivity = 40 dB
Adapter
Worst-case
System Directivity
28 dB
17 dB
14 dB
Page 56
DUT
Termination
DUT has SMA (f) connectors
APC-7 calibration done here
Adapting from APC-7 to SMA (m)
APC-7 to SMA (m)
SWR:1.06
APC-7 to N (f) + N (m) to SMA (m)
SWR:1.05
SWR:1.25
APC-7 to N (m) + N (f) to SMA (f) + SMA (m) to (m)
SWR:1.05
SWR:1.25
SWR:1.15
Calibrating Non-Insertable Devices
When doing a through cal, normally test ports mate directly
 cables can be connected directly without an adapter
 result is a zero-length through
What is an insertable device?
 has same type of connector, but different sex on each port
 has same type of sexless connector on each port (e.g.
APC-7)
What is a non-insertable device?
 one that cannot be inserted in place of a zero-length
through
 has same connectors on each port (type and sex)
 has different type of connector on each port
(e.g., waveguide on one port, coaxial on the other)
What calibration choices do I have for non-insertable
devices?
 use an uncharacterized through adapter
 use a characterized through adapter (modify cal-kit
definition)
 swap equal adapters
 adapter removal
Page 57
DUT
Adapter Removal Calibration





Calibration is very accurate and traceable
In firmware of most analyzers
Port 1
Also accomplished with ECal modules
Uses adapter with same connectors as DUT
Must specify electrical length of adapter to within
1/4 wavelength of highest frequency (to avoid
phase ambiguity)
Cal
Adapter
Port 1
Adapter
B
Port 2
Adapter
B
Port 2
DUT
1. Perform 2-port cal with adapter on port 2.
Save in cal set 1.
Cal Set 1
Port 1
Cal
Adapter
2. Perform 2-port cal with adapter on port 1.
Save in cal set 2.
Cal Set 2
[CAL] [MORE] [MODIFY CAL SET]
[ADAPTER REMOVAL]
Port 1
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DUT
Adapter
B
Port 2
3. Use ADAPTER REMOVAL
to generate new cal set.
4. Measure DUT without cal adapter.
Port 2
What are Balanced Devices?
Ideally, respond to differential and reject common-mode signals
Gain = 1
Differential-mode signal
Balanced to single-ended
Common-mode signal
(EMI or ground noise)
Gain = 1
Differential-mode signal
Fully balanced
Common-mode signal
(EMI or ground noise)
Page 59
Agilent Solution for Balanced Measurements
For RF wireless and general-purpose devices:
•
ENA series is recommended choice
(3...20 GHz)
•
measure standard or mixed-mode Sparameters
•
fixture simulator to embed/de-embed
and transform test port impedances
•
4-port ECal for fast and easy calibration
For microwave or signal-integrity applications:
Page 60
•
consist of network analyzer,
test set, external software
•
time domain, eye diagrams,
RLCG extraction
•
ECal available up to high GHz
Impedanzmessungen mit E5061B
Port-1 reflection method using fixture
e.g., for SMD type components
Gain-phase series-thru method
using fixture for wired components
Page 61
Measuring Nonlinear Behavior
Most common measurements:
 using a network analyzer and power sweeps
 gain compression
 AM to PM conversion
 using a spectrum analyzer + source(s)
 harmonics, particularly second and third
 intermodulation products resulting
RL 0 dBm
from two or more RF carriers
LPF
ATTEN
Page 62
10 dB / DIV
DUT
CENTER 20.00000 MHz
RB 30 Hz
VB 30 Hz
LPF
10 dB
SPAN 10.00 kHz
ST 20 sec
Agilent’s Award Winning Nonlinear Vector Network
Analyzer (NVNA) based on PNA-X Series
Multi-tone and Multi-port Nonlinear Vector Network Analysis
from 10 MHz to 50 GHz
• Two-tone X-parameter measurements
• Multi-tone waveform measurement and
analysis
• Three-port mixer and converter measurements
• Fundamental only X-parameter measurements
Page 63
Programmende
Vielen Dank für Ihr
Interesse an NetzwerkAnalysatoren!
[email protected]
Page 64