A Network Analyzer For Active Components EEEfCom 29-30 Juni ULM Marc Vanden Bossche, NMDG Engineering Remi Tuijtelaars, BSW Copyright 2005 NMDG Engineering Version 2
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 2
Definition of S-parameters As function of frequency f 0 a 1 b 1 a 2 b 2 b b 1 2 ( ( f f 0 0 ) = S ) = S 11 21 ( ( f f 0 0 ) ) a 1 a 1 ( ( f f 0 ) + S 0 ) + S 12 22 ( ( f 0 f 0 ) ) a 2 a 2 ( ( f 0 f 0 ) ) S-parameters are a behavioral model S-parameters describe completely the linear behavior S-parameters cannot be determined properly with one measurement Copyright 2005 NMDG Engineering 3
Measuring S-parameters 50Ω f 0 50Ω f 0 Measurement System Measurement System a 1 b 1 Transistor RFIC System a 2 b 2 Experiment 1 Superposition a 1 b 1 Transistor RFIC System a 2 b 2 Experiment 2 a1 i, b1 i, a2i, b2i with i representing different experiments Analysis b b 1 2 = = S S 11 21 a 1 a 1 + S + S 12 22 a 2 a 2 f 0 Copyright 2005 NMDG Engineering 4
Example: Packaged FET Commercial available FET in fixture Test Port 1 Test Port 2 f 0 Bias Control f 0 : 1GHz - 18 GHz, step = 100 MHz Calibration Short Open Load Thru V gs = -0.3 V V ds = 1.5 V Copyright 2005 NMDG Engineering 5
S-parameter Measurement S11 S12 S21 S22 Copyright 2005 NMDG Engineering 6
S-parameter Measurement with De-embedding Calibration S11 S12 Deembedding S21 S22 Copyright 2005 NMDG Engineering 7
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 8
Nonlinear Behavior - Harmonic Generation 2 GHz Increasing Power Test Port 1 Test Port 2 a 1 a1 = 20 dbm a1 = 0 dbm b 2 Generation of Harmonics Noise Floor b2 2 b Superposition Copyright 2005 NMDG Engineering 9
Nonlinear Behavior - Intermodulation Generation Vector Signal Z Generator 0 2-tone, carrier 2 GHz Vector Signal Analyzer Generation of Intermods a 1 What happens at the input? Vector Signal Analyzer Display What is the meaning of this measurement? Copyright 2005 NMDG Engineering 10
Complete Characterization of Active Components Measurement System Realistic Stimulus Realistic Stimulus v 1 i 1 a 1 b 1 Transistor RFIC System a 2 b 2 v 2 i 2 Representation Domain Physical Quantity Sets Frequency (f) Travelling Waves (A, B) Time (t) Voltage/Current (V, I) Freq - time (envelope) Characterization Copyright 2005 NMDG Engineering 11
Small-Signal Network Analysis: S-parameters 50Ω f 0 50Ω f 0 Measurement System Measurement System a 1 b 1 Transistor RFIC System a 2 b 2 Experiment 1 Superposition a 1 b 1 Transistor RFIC System a 2 b 2 Experiment 2 a1 i, b1 i, a2i, b2i with i representing different experiments Analysis b b 1 2 = = S S 11 21 a 1 a 1 + S + S 12 22 a 2 a 2 f 0 Copyright 2005 NMDG Engineering 12
Large-Signal Network Analysis Measurement System Realistic Stimulus Realistic Stimulus v 1 i 1 a 1 b 1 Transistor RFIC System a 2 b 2 v 2 i 2 Different Experiments a1 i, b1 i, a2i, b2i with i representing different experiments Analysis f ( v g( v 1 1, v, v 2 2, i, i 1 1, i, i 2 2, t, t f ) = 0 f ) = 0 Copyright 2005 NMDG Engineering 13
Large-Signal Network Analysis in a nutshell Measurement System Realistic Stimulus Realistic Stimulus v 1 i 1 a 1 b 1 Transistor RFIC System a 2 b 2 v 2 i 2 Representation Domain Frequency (f) Time (t) Freq - time (envelope) Physical Quantity Sets Travelling Waves (A, B) Voltage/Current (V, I) Analysis f ( v g( v 1 1, v, v 2 2, i, i 1 1, i, i 2 2, t, t f ) = 0 f ) = 0 Characterization Copyright 2005 NMDG Engineering 14
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 15
8753D 30 KHz-3GHz NETWORK ANALYZER ACTIVE CHANNEL CH 1 CH 2 RESPONSE SCALE MEAS FORMAT REF DISPLAY AVG CAL MKR START CENTER STIMULUS MENU MKR FCTN STOP SPAN ENTRY 7 8 9 4 5 6 1 2 3 ENTRY 0. - x1 OFF INSTRUMENT STATE R CHANNEL SYSTEM US ER IN LOCAL PRESET S AVE COPY RECALL SEQ R L T S OUT HP-IB STATUS PROBE POWER FUSED PORT 1 PORT 2 TRANS FWD REFL FWD TRANS REV REFL REV +26 dbm RF 30 VDC MAX PORTS 1&2 AVOID STATIC DISHCARGE @ M k n µ m Vector Network Analyzer Response Acquisition H Stimulus Calibration Reference Planes 50 Ohm S-parameters Analysis Copyright 2005 NMDG Engineering 16
Large-Signal Network Analyzer Response Stimulus Acquisition Modulation Source Calibration Reference Planes 50 Ohm or tuner Complete Spectrum Waveforms Harmonics and Periodic Modulation Copyright 2005 NMDG Engineering 17
Acquisition in LSNA Sampling Converter Filter Filter Filter Filter PC Acquisition Unit LO Capturing broadband HF signals (harmonics and modulation) using low-frequency data - acquisition requires samplers Copyright 2005 NMDG Engineering 18
Representation Domain: Continuos Wave Signal All voltages and currents or waves are represented by a fundamental and harmonics (including DC) X 1 X 0 X 4 X 2 X3 Freq. (GHz) Freq. (GHz) Z 1 DC 1 2 3 4 DC 1 2 3 4 DUT Z 2 Freq. (GHz) DC 1 2 3 4 Complex Fourier coefficients X h of waveforms Freq. (GHz) Freq. (GHz) DC 1 2 3 4 DC 1 2 3 4 Copyright 2005 NMDG Engineering 19
Representation Domain: Amplitude and Phase Modulation of Continuos Wave Signal Phase Amplitude Phasor X 0 (t) X 1 (t) X 2 (t) X 4 (t) Freq. (GHz) Freq. (GHz) Modulation time DC 1 2 3 4 time DC 1 2 3 4 X 3 (t) Slow change (MHz) Fast change (GHz) Z 1 DUT Z 2 Freq. (GHz) time DC 1 2 3 4 Complex Fourier coefficients X h (t) of waveforms Freq. (GHz) Freq. (GHz) time DC 1 2 3 4 time DC 1 2 3 4 Copyright 2005 NMDG Engineering 20
Representation Domain: Periodic Modulated Signals Amplitude Phase X 1i Phasor X 0i X 2i X 3i Periodic Modulation Z 1 DC 1 2 3 Freq. (GHz) DC 1 2 3 Freq. (GHz) DUT Z 2 Freq. (GHz) DC 1 2 3 4 Complex Fourier coefficients X hm of waveforms DC 1 2 3 Freq. (GHz) DC 1 2 3 Freq. (GHz) With proper processing the class of signal is extendable to any type of multi-tone signal Copyright 2005 NMDG Engineering 21
Practical Limitations of LSNA Large-Signal Network analysis will be performed using periodic stimuli one - tone and harmonics periodic modulation and harmonics other types of multi - tones are possible The devices under test maintain periodicity in their response Copyright 2005 NMDG Engineering 22
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 23
LSNA Calibration F 0 =1GHz Stimulus Response DUT a 1 m a 1 m b 1 m a 2 Acquisition DUT a 2 m b 2 Modulation Source DUT b 1 Calibration DUT b 2 Reference Planes 50 Ohm or tuner DUT a 1 DUT b1 DUT a 2 DUT b2 Actual waves at DUT Linear Relationship a b a b m 1 m 1 m 2 m 2 Measured waves Regular VNA Calibration Power Calibration (power meter) Phase Calibration (pulse gen) Copyright 2005 NMDG Engineering 24
Measurement Traceability Relative Cal Phase Cal Power Cal Agilent Nose-to-Nose Standard (*) EOS (NIST) (demonstrated already with NIST) National Standards (*) Licensed to Maury and NMDG Copyright 2005 NMDG Engineering 25
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 26
Available Large-Signal Network Analyzers MT4463A - 20 GHz MT4463B - 50 GHz Copyright 2005 NMDG Engineering 27
Active HF Component Characterization Requirements DC IV Characterization MT4463A/B Modulation Characterization Small-Signal Large-Signal Adding DC Capability Accurate Complete Adding Modulation Capability Active Tuning Passive Tuning Adding Pre-match Tuner Second Source Under different Impedance Conditions Adding Tuners Copyright 2005 NMDG Engineering 28
Example: Packaged FET One connection Complete Characterization Commercial available FET in fixture Test Port 1 Test Port 2 f 0 Frequency Grid: f 0 = 2GHz, 9 harmonics Resolution BW: 1000 Hz Absolute Calibration using SOLT Bias Control Deembedding V gs = -0.3 V V ds = 1.5 V Copyright 2005 NMDG Engineering 29
Large-Signal Measurements - CW - Voltage/Current i1 i2 v1 v2 Time domain Copyright 2005 NMDG Engineering 30
Large-Signal Measurements - CW - Voltage/Current i1 i2 v1 v2 Frequency domain Copyright 2005 NMDG Engineering 31
Large-Signal Measurements - CW - Voltage Waves a1 a2 b1 b2 Time domain Copyright 2005 NMDG Engineering 32
DC-IV curve and RF Load Line (1) 50 Ohm Termination Large-signal - 50 Ohm Termination Copyright 2005 NMDG Engineering 33
DC-IV curve and RF Load Line (2) Open Termination Large-signal - non-50 Ohm Termination Copyright 2005 NMDG Engineering 34
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 35
Periodic Modulation - Multi-tone generation f = 2480. 0 Hz Carrier 2 GHz Modulation Tones 50 Ohm Termination Generation of Multi-tone Copyright 2005 NMDG Engineering 36
Large-Signal Measurements - Modulation - Voltage/Current i1 i2 v1 v2 Frequency domain Copyright 2005 NMDG Engineering 37
Large-Signal Measurements - Modulation - Voltage/Current Zoom into one of the spectral components (fundamental frequency) i1 i2 v1 v2 Frequency domain Copyright 2005 NMDG Engineering 38
Large-Signal Measurements - Modulation - Voltage/Current i1 i2 v1 v2 Frequency - Time domain Copyright 2005 NMDG Engineering 39
Dynamic AM/AM and AM/PM (two-tone 10kHz spacing) Copyright 2005 NMDG Engineering 40
Dynamic HDA (two-tone 10kHz spacing) Copyright 2005 NMDG Engineering 41
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 42
Component Characterization with Passive Tuners DUT Calibration Planes Error-coefficients depend on tuner position Tuner De-embedding Tuner Control + Automatic Correction (Probe(s) and carriage) Copyright 2005 NMDG Engineering 43
Input and Load Impedance under CW Input Impedance of component f 0 Load provided to component Input Impedance of component f 0 Load provided to component Short Terminated 50 Ohm Terminated Tuning Input Impedance of component 2 f 0 Load provided to component Copyright 2005 NMDG Engineering 44
DC-IV curve and RF Load Line with Short Short Terminated Copyright 2005 NMDG Engineering 45
Input and Load Impedance under CW Input Impedance of component f 0 Load provided to component Input Impedance of component f 0 Load provided to component Towards Open Terminated Short Terminated Tuning Input Impedance of component 3 f 0 Load provided to component Copyright 2005 NMDG Engineering 46
DC-IV curve and RF Load Line with Towards Open Towards Open Terminated Copyright 2005 NMDG Engineering 47
Integration with Load-Pull Software The waveforms contain all aspects of the component behavior Copyright 2005 NMDG Engineering 48
Real-Time Component Characterization - Setup Circulator Synthesis of Load Impedances at f 0 Manual Tuner 2f 0 (optional) Vector Signal Generator i 1 i 2 Triplexer DUT f 0 v 1 v 2 f 0 3f 0 (optional) Offset + smart signal to scan amplitude and phase Copyright 2005 NMDG Engineering 49
Real-Time Component Characterization Corresponding Input Impedances Component Characteristic, like Incident Power Delivered Power Copyright 2005 NMDG Engineering 50
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 51
Transistor Model Verification in ADS Measured a 1, including fundamendal and harmonics Model to Certify Measured a 2, including fundamendal and harmonics The model is brought into the same state as the real component The simulated response should be equal to the measured response for a good model The comparison is done at the essential data, common to both: Voltage and Currents Copyright 2005 NMDG Engineering 52
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 53
Measurement-based Behavioral Modeling b b 1 2 ( ( f f 0 0 ) = ) = f g ( a1( f0), a2( f0) ) ( a ( f ), a ( f )) 1 0 2 0 Valid for Range of a1 Closed area on Smith Chart at output Model Prediction Measurement Copyright 2005 NMDG Engineering 54
Measurement-based Behavioral Model in ADS Load-pull Simulation with P in = - 5 dbm and more... Third-Order Intercept Point Copyright 2005 NMDG Engineering 55
Outline Review of S-parameters Theory of Large-Signal Network Analysis The Large-Signal Network Analyzer The Calibration Active Component Characterization under CW stimulus under modulation stimulus in non-50 Ohm environment Modeling Model verification Measurement-based behavioral model Conclusions Copyright 2005 NMDG Engineering 56
Conclusion A Network Analyzer for active component characterization has been presented It measures the essential information (voltage and currents at component ports) to characterize the nonlinear behavior accurately and completely in a unified way from transistor to system under realistic conditions The Network Analyzer is ideal to study the behavior from small-signal to large-signal with one connection using simple and complex signals The Network Analyzer is ideal to certify models The Network Analyzer is ideal to create behavioral models Technical information http://www.nmdg.be www.nmdg.be/ Sales information http://www www.bsw-ag.de/ Copyright 2005 NMDG Engineering 57