Electromagnetic and Circuit Simulation of Injection · PDF fileElectromagnetic and Circuit Simulation of Injection Probes for Bulk Current Injection 2009 CST European User Group Meeting

Electromagnetic and Circuit Electromagnetic and Circuit Simulation of Injection Probes Simulation of Injection Probes

for Bulk Current Injectionfor Bulk Current Injection

2009 CST European User Group MeetingMarch 16-18, 2009, Darmstadtium Congress Centre,

Darmstadt, Germany

POLITECNICO DI MILANO Dept. of Electrical Eng.EMC Group @ POLIMIMilan, Italy

F. Grassi, L. Di Rienzo,F. Grassi, L. Di Rienzo,and S. A. Pignariand S. A. Pignari

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EMC Group @ POLIMI

2009 CST European User Group MeetingMar. 16-18, 2009, Darmstadt, Germany

Research motivationResearch motivation

In real test setreal test set--upsups, the correlationcorrelation between noise levelsnoise levelsexpectedexpected and effectively injectedeffectively injected in the EUT may be seriously jeopardized by

electrically-long wire harness

mismatching at terminations

probe loading effects

multi-wire bundles

Need for unambigous correlationunambigous correlation

circuit/numerical simulation models

real/virtual calibration structures

possible extension to multi-wire cables

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LumpedLumped--Pi circuit modelPi circuit model

Accurate lumpedlumped--PiPi circuit model

recently proposed

F. Grassi, F. Marliani, S. A. Pignari, F. Grassi, F. Marliani, S. A. Pignari, IEEE Trans. EMC,IEEE Trans. EMC, vol. 49, Aug. 2007.vol. 49, Aug. 2007.

represents the probe clamped on the

cable under test

stems from measurement datameasurement dataad hoc procedure of de-embedding

accounts for frequencyfrequency--dependent effectsdependent effects

ferrite complex permeabilty

parasitics, setup-related effects, etc.

C2 C2

L1w0

LC

L2(ω ) M(ω )

L1(ω )

VRF RS

C1CC+

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Experimental characterization Experimental characterization

Estimation of the inductive couplinginductive coupling requires the

knowledge of the complex permeability spectra of the corecomplex permeability spectra of the core

These spectra are retrieved via an experimental procedureexperimental procedureVNA measurementsVNA measurements of the probe input impedanceinput impedance in the absence of secondary circuit

dede--embeddingembedding of the effects due to the primary winding and the input connector/adapter

L1w0LN

L1(ω )C1+ CN

PROBE INPUTPROBE INPUTIMPEDANCEIMPEDANCE

MEASUREMENTMEASUREMENT

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The The ““CoreCore”” problemproblem

)('')(')(ˆ ωµωµωµ rrr j−=

Complex spectraspectra of effectiveeffectivepermeability

inherent responseinherent response of a ferrite specimen

dimensional phenomenadimensional phenomenaeddy currentsdimensional resonances

LL00 coreless self-inductance of the primary winding

Complex and frequencyfrequency--dependent inductancesdependent inductances

10 /)(ˆ)(ˆ NLM r ωµω = dr LNLL 22102 /)(ˆ)(ˆ += ωµω

106-100

0

100

200

300

400

500

107 108Frequency, [Hz]

||µµrr(f)|(f)|µµrr’’(f)(f)µµrr’’’’(f)(f)

)(ˆ)(ˆ01 ωµω rLL =

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Rationale for CST MWS modelingRationale for CST MWS modeling

Why?Why?1.1. validationvalidation and extensionextension of the probe circuit model

2. simulation of set-ups involving multimulti--wire bundleswire bundlesCM vs. DM injection test procedures

3.3. virtual testingvirtual testing for EMC assessment, according to directive 2004/108/CE

4.4. optimizationoptimization of BCI probes designgeometrical dimensionsmaterial properties

How? How? A priori knowledge of :

1. geometrical dimensions of the probe (both outside and insideinside)

2. frequency spectra of intrinsic permeabilityintrinsic permeability of the ferrite core

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CST MWS probe modelCST MWS probe model

Includes Includes probe metallic frame PECprimary winding (wound around the magn. core) PECinput connector/adapter pair PEC & dielectricstoroidal ferrite core freq. dependent material

L. Di Rienzo, F. Grassi, S. A. Pignari, L. Di Rienzo, F. Grassi, S. A. Pignari, ““FIT modeling of injection probes FIT modeling of injection probes for bulk current injection,for bulk current injection,”” in in Proc. ACES 2007Proc. ACES 2007, Verona, Italy , Verona, Italy ..

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EM model of the input connectorEM model of the input connector

The adapter/connector pair is modeled as the chain connection of 3 coaxial lines with Z3 coaxial lines with ZCC = 50 = 50 ΩΩ

Model validationModel validation is obtained via preliminary simulation and VNA measurement of the connector/adapter series, in the absence of the probe ( ( SS1111 ---- 300 kHz 300 kHz –– 600 MHz600 MHz)

f [Hz]106 107 108

-60

-40

-20

0

|S11

| [d

B]

measurementprediction

|S11|

Imag(S11)Real(S11)

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Modeling the ferrite coreModeling the ferrite core

InherentInherent response of the ferrite (i.e., of a ferrite specimenferrite specimen)

usually not available to endnot available to end--usersusersnot retrievable from meas. datanot retrievable from meas. data, due to superposition and interactionwith dimensional phenomena (effective permeability effective permeability spectra)

Iterative procedureIterative procedure for core characterizationguess a frequency modelfrequency modelfit model parametersfit model parameters by comparison vs. Zin meas. until optimal fitting

11stst order DEBYE MODELorder DEBYE MODELDISPERSION PHENOMENADISPERSION PHENOMENA

( )ωτµµµωµ

js

r +−

+= ∞∞ 1

ˆ105 106 107 108 109 10100

100

200

300

400

frequency [Hz]µ r

= µ r' -

j ωµ r''

|µr|

µr'

µr''

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Modeling the ferrite core Modeling the ferrite core contcont’’dd

Preliminary validation of the model

reflection testreflection test, SSinin, at the input port of the probewaveguide port at the adapter input52080 hexahedral cells mesh

in

inin S

SRZ−+

=11

0

Sin

106 107 108-80

-60

-40

-20

0

f [Hz]

S 11[d

B]

Real(S11)

Imag(S11)

|S11|


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Different modeling strategiesDifferent modeling strategies

11stst order DEBYE MODELorder DEBYE MODEL(dispersion phenomena)(dispersion phenomena)

( )ωτµµµωµ

js

r +−

+≅ ∞∞ 1

ˆ

105 106 107 108 109 10100

100

200

300

400

frequency [Hz]

µ r = µ

r' - j

ω µ

r''

|µr|

µr'

µr''

CST MWS EM modelCST MWS EM modelinherent response of the materialinherent response of the material

intrinsicintrinsic permeability spectrapermeability spectra

20

2

201)(ˆ

ωωωµ

+∆++≅

ssAsr

22ndnd order LORENTZ MODELorder LORENTZ MODEL(resonance phenomena)(resonance phenomena)

Circuit model Circuit model (e.g., SPICE)(e.g., SPICE)inherent response + dim. phenomenainherent response + dim. phenomena

effectiveeffective permeability spectra permeability spectra

106 107 108-100

0

100

200

300

400

frequency [Hz]µ r =

µ' r -

j ω µ

'' r

|µr|

µ'rµ''r

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Implementation in SPICEImplementation in SPICE

Inductive couplingInductive coupling:: Preliminary transformationPreliminary transformation

L2(ω )

M(ω )

L1(ω ) V2

I2

V1

I1

V2

I2

V1

I1

L1(ω )

N1:1 L2d

V2'

I1' I1

''V2''

0)(ˆ)(ˆ Λ=Λ ωµω rLL11((ωω), L), L22((ωω), and ), and M(M(ωω) ) proportional toOldOld model

ff--dependent behaviordependent behavior of the core: one parameter onlyone parameter only, i.e., L1(ω)coupling between winding: ideal transformerideal transformer (N1:1)leakageleakage inductanceinductance (L2d): analytically estimatedanalytically estimatedmore suited for SPICE implementation SPICE implementation via ABM modules

NewNew model

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Implementation in SPICE Implementation in SPICE contcont’’dd

V2

I2

V1

I1

L1(ω )

N1:1 L2d

V2'

I1' I1

''V2''

gmV1V1

I2I1=0A VCCSVCCS with transfer function

is used to model the shunted branch, i.e., phenomena due to the core frequency behavior core frequency behavior

)(ˆ11

1

ωωLj

VIgm −=′

=

-++

-

E1

GAIN = 1

V(%IN+, %IN-)

GFREQ/GLAPLACE MODULE

OUT+OUT-

IN+IN-

F1

GAIN = -1

L2d

55 nH

0

2 possible2 possibleABMABM

1. GFREQ module

2. GLAPLACE module

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)(ˆ11

1

ωωLj

VIgm −=′

=

ABMABM VCCSVCCS with gain assigned by a Laplace transform function

GLAPLACE:GLAPLACE: Main feature

• retrieved from measurement dataretrieved from measurement data (evaluation of the effective permeability spectra of the ferrite core)

• approximated by means of a proper transfer functiontransfer function with parameters obtained from measurement dataobtained from measurement data

Implementation in SPICE Implementation in SPICE contcont’’dd

106

107

108-100

0

100

200

300

400

500

f, [Hz]

| µr (f)|

µr '(f)

µr ''(f)

FROM MEASUR

LORENTZ

GLAPLACE:GLAPLACE: Application

VCCS gain

F. Grassi, F. F. Grassi, F. MarlianiMarliani, S. A. Pignari , S. A. Pignari ““SPICE modeling of BCI probes accounting for the SPICE modeling of BCI probes accounting for the frequencyfrequency--dependent behavior of the ferrite core,dependent behavior of the ferrite core,”” in in Proc.Proc. XIXth URSI GAXIXth URSI GA, 2008., 2008.

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Validation/Calibration fixtureValidation/Calibration fixture

l hw

Mechanical layoutMechanical layoutsingle-ended interconnectionSMA terminal connectorsmetallic vertical strips

Calibration fixture vs. std. JIGJIGmismatching at terminationsopen structure (as for real wiring)

3

2

1

Complete BCI test setBCI test set--upupvalidation purposesSP meas. at the 3 ports

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Modeling the validation fixtureModeling the validation fixture

Pass-through SMA connectors

coaxial lines with ZZCC = 50 = 50 ΩΩSP at the output ports up to 600 MHz600 MHz

waveguide ports (outside the strips)

246960 hexahedral cells

25 lines per wavelength

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Validation of the fixture modelValidation of the fixture model

106 107 108-80

-60

-40

-20

0

f [Hz]


Imag(S11)

Real(S11)

|S11|

106 107 108

-80

-60

-40

-20

0

f [Hz]


Imag(S12)Real(S12)

|S12|

SS1111= S= S22 22 [dB][dB]

1

2

SS2121= S= S12 12 [dB][dB]

1

2

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CST MWS virtualCST MWS virtual measurementmeasurement

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡

−−=

331313

131112

131211

3

SSSSSS

SSSS

SP measurement at the output ports -- 300 kHz 300 kHz –– 400 MHz400 MHz

1484100 mesh cells25 lines/wavelengthpulse duration: 6 ns136 MByte of memory 3 h - 3.4 GHz Pentium Xeon workstation steady state accuracy limit -60 dB

HOW TOHOW TO……??

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Model Validation up to 400 MHzModel Validation up to 400 MHz

SS1111= S= S22 22 [dB][dB] SS2121= S= S12 12 [dB][dB]

107 108-80

-60

-40

-20

0

frequency [Hz]106


Real(S11)

Imag(S11)

|S11|

107 108-80

-60

-40

-20

0

frequency [Hz]106


|S21|

Real(S21)

Imag(S21)

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Model Validation up to 400 MHzModel Validation up to 400 MHz

SS1313= = --SS23 23 [dB][dB] SS33 33 [dB][dB]

107 108-80

-60

-40

-20

0

frequency [Hz]106


Real(S13)

Imag(S13)

|S13|

106 107 108-80

-60

-40

-20

0

frequency [Hz]


Real(S33)

Imag(S33)

|S33|

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ConclusionConclusion

Main stepsMain steps

1.1. EM EM model of themodel of the BCI probeBCI probe

CAD modeling of the probe & input connector/adapterCAD modeling of the probe & input connector/adapterCharacterization of the Characterization of the ff--response of the ferriteresponse of the ferrite corecore

first order first order DebyeDebye modelmodel for representing intrinsic properties

circuit modeling via SPICE for explaining the differences between differences between EM and circuital modelingEM and circuital modeling

2.2. EM EM model of themodel of the validation fixturevalidation fixture

Validation up to Validation up to 400 MHz400 MHz

Possible applicationsPossible applicationsVirtual test setVirtual test set--up up for EMC assessment EMC assessment & circuit modelcircuit model extension extension to the case of multimulti--wire bundleswire bundles

Design optimization Design optimization of injection devices

Electromagnetic and Circuit Simulation of Injection · PDF fileElectromagnetic and Circuit Simulation of Injection Probes for Bulk Current Injection 2009 CST European User Group Meeting

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