NVNA & X-Parameters – MTT 2008
Jack Sifri May 15, 2008Page 1
The new paradigm for nonlinear measurements, modeling, and simulation with ADS of nonlinear components
Agilent NVNA & X-Parameters
NVNA & X-Parameters – MTT 2008
Jack Sifri May 15, 2008Page 2
Measuring nonlinearities for use directly in design
A1,P1
F1in
F1out
F2out
F3out
A1,P1A2,P2
A3,P3
Wouldn’t it be nice if you could measure and display the full amplitude and phase information of each spectral component? Wouldn’t it be even nicer to then use it directly in ADS harmonic balance or circuit envelope simulation?
NVNA & X-Parameters – MTT 2008
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Nonlinear Vector Network Analyzer (NVNA): The new industry standard for nonlinear measurements
NVNA & X-Parameters – MTT 2008
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S-parameters: linear measurement, modeling, & simulation
NVNA & X-Parameters – MTT 2008
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What are X-Parameters?
X-parameters are the mathematically correct superset of S-parameters, applicable to both large-signal and small-signal conditions, for linear and nonlinear componentsThe math exists!
We can measure, model, & simulate with X-parameters Each part of the puzzle has been created The pieces now fit together seamlessly
NVNA & X-Parameters – MTT 2008
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X-parameters come from the Poly-Harmonic Distortion (PHD) Framework
NVNA & X-Parameters – MTT 2008
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X-parameter Concept: Approxs. to NL Mapping
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X-Parameters: Why They are Critical:
, ,
( )11
( )( ), 1 1
,,1
*1(| |) (( ) )
ef g gh ef hef
S fF fe f
T f hgh
g
hgh
g h hB X X A AA P A X P AP − + ⋅= +⋅+∑ ∑
X-Parameters: Why They are CriticalPredict performance of cascaded NL components
11( )j AP e ϕ= “New” Terms!
Cascaded Nonlinear Amplifiers: Nonlinear effects of mismatch versus drive
•Unambiguously identifiable (simple, automated extraction) from automated set of measurements•Fully nonlinear vector quantities (Magnitude and phase of all harmonics)•Extremely accurate for high-frequency, distributed nonlinear circuits•Cascadable (correct behavior in mismatched environment)
NVNA & X-Parameters – MTT 2008
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Results: Design of Cascade vs. Measurement of Cascade
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Amplitude Calibration
Vector Calibration
Phase Calibration
Phase Reference
X-Parameter extraction/multi-tone source
Standard PNA-X Network Analyzer
New!! Agilent Calibrated Phase Reference
New!! Agilent NVNA
NVNA System Configuration
NVNA & X-Parameters – MTT 2008
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Black-Box Characterization & Behavioral Modeling
Actual Amp Circuit
Design of Module or Instrument Front End
Detailed Circuit Model (SPICE/ADS) of IC
Measurement-Based Model• Circuit models don’t exist• Completely protect design IP
Generate Behavioral
Model
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PHD Framework: Simulating with Measured Data
Memory Interface
NVNA ApplicationTake X-parameter
measurements
Agilent PHD CodeExtract X-parameters
Export model file
Works inHB and Envelope,Not in Transient
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Example: X-Parameters Verification
Amplifier component models from individual measured X-parameters
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Results Cascaded Simulation vs. Measurement
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Third Order Intercept Simulation
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Input / Output Spectrums & ACPR
SpectralRe-growth
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PA Linearization using X-Parameters in ADS Digital Pre-Distortion Linearization Design Guide
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Summary