determing amplifier nonlinearities by using “real-world“ signals · 2016-11-30 · fundamentals...
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2 MAR | Re | 08/00 |
11MAA | 10.03 | MW 1 Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
Determing Amplifier Nonlinearities by using “Real-World“ SignalsEuropean Microwave Week 2003
Martin Weiß, ApplicationsMartin.Weiss@RSD.ROHDE-SCHWARZ.COM
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 2
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Table of Contents
Techniques and FundamentalsDifferent Measurement Methods:
- Swept Power Measurement- Two-Tone Measurement- Measurement with a real signal – Any Stimulus- Measurement with a real signal – Modulated Stimulus
Conclusion
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 3
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Techniques and FundamentalsProblem
Ref -12 dBm Att 0 dB*
**
*2 RMVIEW
* B SGL
RBW 10 kHz
VBW 100 kHz
SWT 10 s*
Center 1 GHz Span 4 MHz400 kHz/
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
CH PWR -11.32 dBm
ACP Low -35.23 dB
ACP Up -35.55 dB
Ref -12 dBm Att 0 dB
RBW 10 kHz
VBW 100 kHz
SWT 10 s*
***
*
Center 1 GHz Span 4 MHz400 kHz/
1 RMVIEW
BSGL
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
CH PWR -11.46 dBm
ACP Low -65.86 dB
ACP Up -65.85 dB
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 4
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Techniques and FundamentalsGoals
Predistortion Method:DigitalPredistortion
Measure:AM/AM and AM/PMcompression curve
Model:Polynomial approximation
Goal:Low ACP and EVM values
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 5
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Swept Power MeasurementResults with a Network Analyzer
Increase powerFAST
Increase powerSLOW
Decrease powerFAST
Decrease powerSLOW
Pin
Pin - Pout
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 6
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Two tone measurementPrincip of Measurement
Measurement with a two-tone signalWhich modulation frequency fm must be selected?
f0 f0 + fmf0 - fm
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 7
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Two tone measurementTypical Result with different Modulation Frequencies
Tones
K3
K5
Colors:Different modulation frequencies
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 8
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Two Tone MeasurementThe new R&S Vector Signal Generator SMU
For more information, visit our stand
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 9
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Results with different test signalsCW – Multi-Tone - Pulse
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 10
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Results with different test signalsConclusion
The crest factor of the stimulus signal has a significantinfluence on the measured AM/AM and AM/PM compression curve
CONSEQUENCE:Measurements need to be performed on a signalwith the same bandwidth and crest factor as in real operation conditions
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 11
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any StimulusTest Setup Overview – R&S Software AmpTune
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 12
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any StimulusMeasurement Steps
Generate the test signal or load it via fileAdjust the DUT input level for the desired RMS output levelDownconvert the RF signal to IQ baseband and sample itPerform a synchronizationCalculate the AM/AM and AM/PM modelPredistore the test signalVerify the predistortion effect
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 13
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any Stimulus Available Test Signals
Bandlimited Noise (generated internally)Two Tone (generated internally)Signals from WinIQSIM (import via file)Signals from many simulation tool (import via IQWizard)NPR (Noise Power Ratio) signals(import via IQWizard, generation via NPR tool)
http://www.rohde-schwarz.com -> Application Notes
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 14
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any Stimulus Key Features
Precise timing synchronisation and delay calculationAuto-leveling of the DUT output powerMeasurement of RF-to-RF devices (Amplifiers, …)Measurement of IQ-to-RF devices (direct-upconverter, …)Support of all R&S Signal Generators and IQ Sources(AMIQ, SMIQ-B60, SMIQ, SMU)Support of all R&S Signal and Spectrum Analyzers(FSIQ, FSP, FSU, FSQ)HTML Measurement Report including curve coefficientsFree-of-charge software
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 15
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any Stimulus Signal Processing
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 16
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any Stimulus AM/AM and AM/PM Measurement and Predistortion
AM/AM curve AM/AM predistortion
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 17
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any Stimulus Predistortion Results with 8 MHz signal, 10 dB Crest
Withpredistortion
-61.23 dBALT1 Up
-61.12 dBALT1 Low
-58.28 dBACP Up
-58.09 dBACP Low
-11.25 dBmCH Power
Withoutpredistortion
-61.85 dBALT1 Up
-61.73 dBALT1 Low
-44.47 dBACP Up
-44.46 dBACP Low
-11.26 dBmCH Power
RF AmplifierCDMA signal, 8 MHz BW
-80
-70
-60
-50
-40
-30
-20
-10
-24,0 -20,0 -16,0 -12,0 -8,0 -4,0 0,0 4,0 8,0 12,0 16,0 20,0 24,0
Frequency Offset [MHz]
Leve
l [dB
m]
PredistoredOriginal
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 18
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Any Stimulus Free software AmpTune from Rohde & Schwarz
http://www.rohde-schwarz.com/AppNote/1MA27
10
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 19
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Modulated Measurement with Rohde & Schwarz FSQ & FSQ-K70
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 20
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Modulated Principals of Operation – Vector Signal Analysis
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 21
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Real Signal – Modulated Measurement with Rohde & Schwarz FSQ-K70
Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 22
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
ConclusionOverview over the Presented Methods
FSQFSP/U/QFSP/U/Q
NetworkAnalyzer
ZVxAnalysator
NOYESNONOMeasurementReport
Vector Mod.Signal
AnySignal
TwoTone
SingleCarrierStimulus
---AmpTune---Software
SMIQ / SMUSMIQ / SMUSMU
---
Generator
NOYESNONOAutomaticPredistortion
HIGHHIGHHIGHLOWMeasurementBandwidth
YESYESPARTLYNOSuitable forAmplifier Test
Real SignalFSQ-K70
Real Signal„AmpTune“Two ToneSwept Power
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Nonlinear Measurement TechniquesEuropean Microwave Week 2003 - Munich
1MAA | 10.03 | MW 23
FundamentalsTechniques
Swept Power Measurement
Two Tone Measurement
Real SignalAny Stimulus
Real SignalModulated
Conclusion
Thank you for your attention!For additional information, please visit our stand
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