A Network Analyzer For Active Components
EEEfCom 29 - 30 Juni ULM
Marc Vanden Bossche, NMDG Engineering
Remi Tuijtelaars, BSW
2
Outline
O Review of S-parameters
O Theory of Large-Signal Network Analysis
O The Large-Signal Network Analyzer
O The Calibration
O Active Component Characterization
– under CW stimulus
– under modulation stimulus
– in non-50 Ohm environment
O Modeling
– Model verification
– Measurement-based behavioral model
O Conclusions
Definition of S-parameters
) ( ) ( )
( ) ( )
(
) ( ) ( )
( ) ( )
(
0 2 0 22 0
1 0 21 0
2
0 2 0 12 0
1 0 11 0
1
f a f S
f a f S f
b
f a f S f
a f S f
b
+
=
+
=
a 1 b 1
a 2 b 2
As function of frequency f 0
• S-parameters are a behavioral model
• S-parameters describe completely the linear behavior
• S-parameters cannot be determined properly with one measurement
4
Measuring S-parameters
2 22 1
21 2
2 12 1
11 1
a S a
S b
a S a
S b
+
=
+
=
Transistor RFIC System
Measurement System
a 1
b 1
O Analysis
s experiment different
ng representi with
, ,
, 1 2 2
1
i
b a b
a i i i i
a 2
b 2
50 Ω
Experiment 1
Transistor RFIC System
Measurement System
a 1
b 1 2
a b 2
Ω 50
Experiment 2
f 0 f 0
f 0
Superposition
Example: Packaged FET
Commercial available FET in fixture
Test Port 1
Test Port 2
Calibration
Bias Control
V gs = -0.3 V V ds = 1.5 V Short
Open Load Thru f 0 : 1GHz - 18 GHz, step = 100 MHz
f 0
6
S-parameter Measurement
S 11 S 12
S 21 S 22
S-parameter Measurement with De-embedding
Calibration
Deembedding
S 11 S 12
S 21 S 22
8
Outline
O Review of S-parameters
O Theory of Large-Signal Network Analysis
O The Large-Signal Network Analyzer
O The Calibration
O Active Component Characterization
– under CW stimulus
– under modulation stimulus
– in non-50 Ohm environment
O Modeling
– Model verification
– Measurement-based behavioral model
O Conclusions
Nonlinear Behavior - Harmonic Generation
Test Port 1
Test Port 2 Increasing
Power
b 2 a 1
2 GHz
dBm
a 1 = − 20 a 1 = 0 dBm
Noise Floor
b 2 b 2
Generation of Harmonics
Superposition
10
Nonlinear Behavior - Intermodulation Generation
Vector Signal
Generator Z 0 Vector Signal
Analyzer
a 1
2-tone, carrier 2 GHz
Vector Signal Analyzer Display What happens at the input?
Generation of Intermods
What is the meaning of this measurement?
Complete Characterization of Active Components
Transistor RFIC System Realistic
Stimulus
Realistic Stimulus
Measurement System
v 1
i 1
v 2
i 2
a 1
b 1
a 2
b 2
O Physical Quantity Sets
–
Travelling Waves (A, B)
–
Voltage/Current (V, I)
O Representation Domain
–
Frequency (f)
–
Time (t)
–
Freq - time
(envelope)
12
Small-Signal Network Analysis: S-parameters
2 22 1
21 2
2 12 1
11 1
a S a
S b
a S a
S b
+
=
+
=
Transistor RFIC System
Measurement System
a 1
b 1
O Analysis
s experiment different
ng representi with
, ,
, 1 2 2
1
i
b a b
a i i i i
a 2
b 2
50 Ω
Experiment 1
Transistor RFIC System
Measurement System
a 1
b 1 2
a b 2
Ω 50
Experiment 2
f 0 f 0
f 0
Superposition
Large-Signal Network Analysis
Transistor RFIC System Realistic
Stimulus
Realistic Stimulus
Measurement System
v 1
i 1
v 2
i 2
a 1
b 1
a 2
b 2
0 )
| , , , , (
0 )
| , , , , (
2 1 2 1
2 1 2 1
=
= f t i i v v g
f t i i v v f
O Analysis
s experiment different
ng representi with
, ,
, 1 2 2
1
i
b a b
a i i i i
Different Experiments
14
Large-Signal Network Analysis in a nutshell
Transistor RFIC System Realistic
Stimulus
Realistic Stimulus
Measurement System
v 1
i 1
v 2
i 2
a 1
b 1
a 2
b 2
0 )
| , , , , (
0 )
| , , , , (
2 1 2 1
2 1 2 1
=
= f t i i v v g
f t i i v v f
O Physical Quantity Sets
–
Travelling Waves (A, B)
–
Voltage/Current (V, I)
O Representation Domain
–
Frequency (f)
–
Time (t)
–
Freq - time (envelope)
O O Analysis Analysis
Characterization
Outline
O Review of S-parameters
O Theory of Large-Signal Network Analysis
O The Large-Signal Network Analyzer
O The Calibration
O Active Component Characterization
– under CW stimulus
– under modulation stimulus
– in non-50 Ohm environment
O Modeling
– Model verification
– Measurement-based behavioral model
O Conclusions
16
Vector Network Analyzer
50 Ohm
Acquisition
Calibration
Analysis S-parameters
Stimulus
Response
Reference Planes
H
MEASFORMATSCALE REF DISPLAYAVG CAL MKRFCTN MKR CH 1CH 2
MENU
START STOP
CENTER SPAN
SYSTEMLOCALUS ER PRESET COPYSAVE
RECALLS EQ
7 89
4 56
1 23
0 .-
@ n
M µ k m
ENTRY x1 OFF ACTIVE CHANNEL
RESPONSE
STIMULUS ENTRY
INSTRUMENT STATE R CHANNEL
OUT
RLTS
HP-IB STATUS IN
PROBE POWER FUSED
PORT 1 PORT 2
TRANS FWD
REFL FWD TRANS REV
REFL REV +26 dBm RF 30 VDC MAX P ORTS 1&2 AVOID S TATIC DIS HC ARGE 8753D
NETWORK ANALYZER30 KHz-3GHz
Complete Spectrum Waveforms
Harmonics and Periodic Modulation
50 Ohm or tuner
Acquisition
Calibration Stimulus
Response
Reference Planes
Modulation Source
Large-Signal Network Analyzer
18
Acquisition in LSNA
Filter Filter
Filter Filter
PC Acquisition Unit
LO
Sampling Converter
Capturing broadband HF signals (harmonics and modulation) using low-frequency data - acquisition
requires samplers
Representation Domain: Continuos Wave Signal
Freq. (GHz)
1 2 3 4
DC
DUT Z 1
Z 2
Freq. (GHz)
1 2 3 4
DC
Freq. (GHz)
1 2 3 4
DC
Freq. (GHz)
1 2 3 4
DC
Freq. (GHz)
1 2 3 4
DC
All voltages and currents or waves are represented by a fundamental and harmonics (including DC)
Complex Fourier coefficients X h of waveforms
X 0 X 1
X 2 X 3
X 4
20
Representation Domain: Amplitude and Phase Modulation of Continuos Wave Signal
Freq. (GHz)
1 2 3 4
DC
Z 1 DUT Z 2
Freq. (GHz)
1 2 3 4
DC
Freq. (GHz)
1 2 3 4
DC
Freq. (GHz)
1 2 3 4
DC
Freq. (GHz)
1 2 3 4
DC
Complex Fourier coefficients X h (t) of waveforms
Phasor
Amplitude
Phase
Fast change (GHz) Slow change (MHz)
Modulation
X 0 (t)
X 1 (t) X 2 (t)
X 3 (t)
X 4 (t)
time
time time
time time
Representation Domain: Periodic Modulated Signals
Freq. (GHz)
1 2 3 4
DC
DUT Z 1
Z 2
Freq. (GHz)
1 2 3
DC
Complex Fourier coefficients X hm of waveforms
Freq. (GHz)
1 2 3
DC
Freq. (GHz)
