An Electromagnetic Emission Model for Integrated Circuits

Transcription

1 An Electomagnetic Emission Model fo Integated Cicuits Pete Kalicek FhG-IZM Padebon/Belin Univesity of Padebon ieee.og 16 Mach 2001

2 Oveview Motivation/Intoduction Geneal Modeling Poposed Emission Model Modeling example Summay Page 2

3 Motivation: Poblems and thei solutions System/PCB analysis: IC typically modeled by equivalent cicuits no diect contibutions to emitted field Not sufficient fo today s high clock ates and complex packaging Complete analysis of IC/package and PCB/system not possible: - high complexity - scale level diffeences only pacticable fo small substuctues Development of maco-models epesenting essential popeties Page 3

4 Modeling: Requiements Requiements fo an emission model: Good appoximation of emitted fields (nea- and fa field) Low numbe of model paametes Paamete detemination via measuement and simulation Simple integation into existing commecial tools fo system/pcb analysis Consideing diffeent opeation modes and connected cicuity Page 4

5 Modeling: Diffeent appoaches Some possibilities of modeling EM-fields: Equivalence pinciple (known field values aound IC) Supeposition of plane waves (plane-wave spectum) Equivalent adiating stuctues: - simple antennas: dipoles, loops (constant cuent distibution) - patch antennas - antennas with non-constant cuent distibution Multipole Expansion of electomagnetic field Page 5

6 Modeling: Multipole Expansion I Solution of vecto wave equation in spheical coodinates: e,m C E,B, Π E = Π ( 2 + k ) C = 0 e jωµ Π m { } leads to field expansion in othogonal functions: Π A e j = Π k m n m n,m n,m hn(k) Pn (cosϑ) cos(mϕ) + n= 1 m= 0 Cn,m / Z0 Dn, m / Z0 H = Π + jωε Π m B sin(mϕ) e e Expansion of el. and magnetic field in space outside souces Page 6

7 Modeling: Multipole Expansion II Dipole Quadupole Octupole Hexapole Page 7

8 Poposed Model: Simple Emission Model Simple Emission Model (SEM) E, H U s, I s Spice-, Macomodel Multipole model + Valid in nea- and fafield + physical model + paamete detemination via measuement o simulation - no consideation of extenal cicuity Model paametes: Multipole coefficients Optionally diffeent opeation modes Page 8

9 Poposed Model: Contolled Emission Model Voltage Contolled Emission Model (VCEM) Pot Contolled model E, H U i Electomagnetic equivalent model: voltages at IC pots contol modal emissions U s, I s Spice-, Macomodel + consideation of extenal cicuity paasitics effects (unintentional signals) Page 9

10 Poposed Model: Modeling Wokflow Souce Modeling Geometic Data Neafield Scans EM Field Calculation with(fem, MoM...) Appoximation of Fields: MME (Multiple Multipole Expansion) Optional Fafield Tansfomation Enhancement of Simulatos on PCBand Systemlevel Model Paamete Detemination IBIS Models Page 10

11 Poposed Model: Integation into High-Level Tools Use of models with weak coupling in fieldsolve COMORAN Calculation of cuent and adiated fields consideing the IC emissions only minimal incease in calculation time (MoM matix dim. constant) Linea system of equations to detemine unknown cuents: A x = E Multipol b Supeposition of ight side b by field contibution of multipoles Page 11

12 Poposed Model: Coupling mechanisms Coupling mechanisms coveed by poposed models Page 12

13 Example: Complex Configuation Two IC with an antenna stuctue in the nea-field Side view of configuation Top view of configuation Image theoy used fo simplification, Simple Emission Model used Page 13

14 Example: Complex Configuation IC/package Simple geometic package model used to allow fullwave efeence calculation of complete configuation Cuent distibution at f=2ghz Page 14

15 Example: Excitation Excitation signal Respective spectum (up to 3GHZ) Page 15

16 Example: Neafield-Effects Time domain voltage at antenna esisto ed = Model; blue = efeence Mag. Of cuent on antenna at f = 2 GHz Page 16

17 Example: Fafield-Effects Radial pat of Poynting vecto at f = 3 GHz in plane x=const. ed = Model; blue = efeence Spectum of x-component of electical field 3m above Page 17

18 Example: Compaison to Dipole Model E-field 3m above stuctue; ed: E x, blue E y, puple E z ; pue electic dipole model (left) and multipole model (ight) Page 18

19 Example: Computational Effot Computational esouces: Efficient consideation of electomagnetic IC emission Enable fast analysis of diffeent configuations design optimizations Page 19

20 Summay High complexity of IC expensive modeling necessay no integation in system design possible Use of Multipole expansion as maco-model low numbe of necessay paametes Simple integation in PCB- and system-level tools Good ageement with full-wave efeence calculations Substantial gain of computational- and memoy esouces Page 20