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

Jack Sifri May 15, 2008Page 3

Nonlinear Vector Network Analyzer (NVNA): The new industry standard for nonlinear measurements

NVNA & X-Parameters – MTT 2008

Jack Sifri May 15, 2008Page 4

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

Jack Sifri May 15, 2008Page 6

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

NVNA & X-Parameters – MTT 2008

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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

Jack Sifri May 15, 2008Page 9

Results: Design of Cascade vs. Measurement of Cascade

NVNA & X-Parameters – MTT 2008

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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

NVNA & X-Parameters – MTT 2008

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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

NVNA & X-Parameters – MTT 2008

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Example: X-Parameters Verification

Amplifier component models from individual measured X-parameters

NVNA & X-Parameters – MTT 2008

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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