Real World Cable Modeling in
CST STUDIO SUITE™
 Interference, susceptibility and radiation analysis
Edoardo Genovese
Sales and Applications engineer
CST AG
www.cst.com | CST workshop series 2010 | February 10 | 1
What EM Simulation and CST STUDIO SUITE™ are
•
As Electromagnetic Simulation we define the set of numerical and virtual analysis tools used
to emulate electromagnetic phenomena.
EMC
Antennas and propagation
•
CST STUDIO SUITE™ is the leading tool for the 3D EM simulation of electronic components. CST
products allow to characterize, design and optimize electromagnetic devices before going into
the lab or measurement chamber.
•
Nowadays EM Simulation is commonly used in many industries:
Electronics & Telecommunications
Defense & Avionics
…and last but not least…
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Medical Equipment
Automotive
Our Markets
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CST’s Product portfolio
 CST MICROWAVE STUDIO®
 CST DESIGN STUDIO™
 CST EM STUDIO®
 CST PARTICLE STUDIO®
 CST PCB STUDIO™
 CST CABLE STUDIO™
 CST MICROSTRIPES™
 CST MPHYSICS STUDIO™
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The problem…
MWS
cable
modeling
Dimensions:
Total cable length in [km]
Chassis in [m]
Cable cross-sections in[mm]
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Approach 1: brute force!
For 3D EM field analysis only:
With cables included: more than 200,000,000 mesh cells!
 Small geometry  small cells  many mesh cells
 Small detail  small time step  longer simulation
 T, F, I solvers are no option!
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Approach 2: hybrid solution
MWS (or MS): 3D EM field calculation
CS: 2D transmission line analysis
• Automatic geometry update
• Co-simulation (field calculation & network analysis)
• Capability of emission and susceptibility analysis
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3D field calculation / susceptibility
• Electromagnetic field distribution in 3D
• Calculation of Etan along cable routes
• Determination of induced voltages in cables
• Currents & voltages by network analysis
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Voltage time signals in [V]
Voltage monitors along cable route
Individual voltage signals for each monitor
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Network analysis
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Emission from cable harness in car chassis
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H-field @ 500 MHz
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Lightning analysis
200 kA double exponential pulse, 1.5 ms rise, 88ms fall
CAT 5
cable
lightning
exit wire
lightning current
injected into nose
• Hybrid approach required due to vastly different scales
• MS 3D TLM model includes door seams, windows and
carbon composite wing box
• CS TL model used for the CAT 5 cable
• Susceptibility analysis to determine lightning response
www.cst.com | CST workshop series 2010 | February 10 | 13
Time-domain H field response
Computer
requirements
710k mesh cells
386 Mbytes RAM
12 hours on 8 core 2.67 GHz
Intel Xeon Desktop Computer
• External H field follows the lightning strike waveform
• Attenuated response behind the door seam
• Slower diffusion waveform near the composite wing box
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Network analysis
Cable resonance
aligns with airframe
resonance
resonances detected at
4.2, 12.4, 21 MHz
36m long aircraft
approximately l/2 at 4.2 MHz
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H field time animation
Time cycling from 0 to 100 ms
Early time: Coupling through cockpit glass / door seams
Late time: Diffusion through composite wing box
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System level simulations
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Component Coupling via S-Matrix
CST MICROWAVE STUDIO
CST CABLE STUDIO
CST PCB STUDIO
CST PCB STUDIO
CST MICROWAVE STUDIO
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Summary
Enhanced simulation possibilities
thanks to the hybrid approach
Large complex simulations possible in
realistic time scales
Wide application range including
cable interference, susceptibility and
emissions
System simulations thanks to the
Complete Technology
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Grazie per la vostra attenzione!
Per domande o dimostrazioni pratiche siete
i benvenuti al nostro stand
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