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Modelling techniques for High Speed Digital Systems

2 www.cst.com | Jul-08

EDA / ElectronicsTypical Requirements

Signal propagation

Eye diagrams

Spice models

TDR

Near End / Far End Crosstalk

Conducted emission

Radiated emission

Workflow Integration

CST PCB STUDIO™CST CABLE STUDIO™

CST EM STUDIO™

CST MICROWAVE STUDIO®CST DESIGN STUDIO™

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Typical structures

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Possible scenario

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BNC MWS model > Hex and/or Tet mesh

Sim. Time=10sec in time domain

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Model validation > comparison time and frequency domain

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1GHz

5GHz

10GHz

Port mode and electric field plots

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SMA launch connector

Cross section

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Time and frequency domain analysis

Input signalOutput signal

reflected signal

Insertion loss

Return loss

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TDR

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Port Modes > TEM and Quasi-TEM

E-field @ 10GHz

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Stripline transition model with 2 SMAs

Stripline length

SMA2 modeled via copy + paste

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Measured Vs. Simulated results

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Samtec connector model > Hex and/or Tet mesh

Simulation Time=12min in time domain

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Model validation > comparison time and frequency domain

Return lossInsertion loss

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Surface current plots

1GHz

3GHz

6GHz

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More complex connectors Airmax FCI – still CST MWS

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CST PCB STUDIO

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CST Design Studio

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S-parameters dB

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Z-Y parameters

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Transient Analysis and eye diagram

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Effect of the BNC connector on the eye diagram opening

The touchstone of the BNC connector is de-embedded

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Integration of Simlab tools intoCST STUDIO SUITE

CST PCB STUDIO

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CST PCB STUDIOAll major GUI-Elements are inserted into CST DESIGN ENVIRONMENT™ windows.

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2D TL method

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3D PEEC Method

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Radiation Simulations I(Exchange Geometry)

Export layout data as CST Microwave Studio project

Open project in CST MICROWAVE STUDIO

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Export simulated 3D - currentdistribution. (RSD - File is created)

In CST MICROWAVE STUDIO:Import the current distribution.

Radiation Simulations II(Exchange Stimulation)

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Equivalent source and/or Compact model (#)

(#) A. Ciccomancini Scogna, “A simulation strategy for RFI/EMI analysis of Printed Circuit Board in complex system environment” to be published on Conformity magazine –www.conformity.com

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EMC-EMI analysis

0.5GHz 1GHz

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EMC-EMI analysis for more complex models

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Subgridding helps again

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Surface Current distribution – 1GHz

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…for even more complex metallic enclosures

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H-field at 1GHz

With honeycomb panel

Without honeycomb panel

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Link with Sigrity

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More complex PCBs and/or packages –still CST MWS

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Workflow Integration

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CST STUDIO SUITE(TM) 2008

PCB layout and Package import

41 www.cst.com | Jul-08

On-Line ExampleODB++ PCB import

odb_on_line.zip