Workshop on ESI Solutions in Computational Electromagnetics (CEM)

12 -08-2014 to 13-08-2014Venue: Department of Electronics and Communication Engineering Vasavi College of Engineering(A) A.Srilakshmi Assoc. Professor, ECE Dept Vasavi College of Engineering

The main aim was to attend this workshop is to understand the concepts of computational Electromagnetics related to design and simulation of antenna.

ContentsIntroductionApplicationsOver view of CEM Numerical SolversCEM Solver TechniquesGraphical User InterferenceConclusion

Introduction to CEMMaxwells equations describe electromagnetic field phenomenaCEM = Computational electromagnetic CEM is the numerical solution of Maxwells equationsCEM has become an indispensable industrial tool Applications include the design and analysis of:Circuits; electrical systems; antennasComputer modelingNumerical analysisCEM tool

CEM APPLICATIONS.Antenna design- All kind of antennas including horn, reflector, wire and microstrip antennas as well as broadband antennas and antenna arrays.

Antenna integration- Radiation pattern of installed antennas on large platforms such as aircraft or ships. Coupling between installed antennas.

Microwave design- Typical applications includes design of filters, connectors and couplers.

EMI/EMC interaction -Analysis of a wide range of EMC/EMI problems including shielding and coupling.

Scattering & radar cross-section- RCS analysis of structures such as aircraft, ships, air-intakes, exhausts, and antennas.

Applications

Wire antennas

Horn antennas

Planar microstrip

Large array

Reflector antennas

Broadband

A Variety of IndustriesElectromagnetic Solutions forAutomotive AeronauticsDefenseTelecommunication

Automotive & Ground transportationEMC/EMI with internal cablingActive Safety & RADAR devicesWindshield AntennasIndustrial Sectors *

AERONAUTICS & DEFENSEThunder Lightning & Stealth EMC/EMI with internal cablingAntenna integrationIndustrial Sectors contd.*

Automotive EMC

Which method is to be used ?Overview of CEM Numerical solvers*POMLFMMMoMFDTDFEMMTLCEM Solutions 2013

CEM solvers techniquesMDMM MultiDomain MultiMethod

*Hybrid solvers coupling full-wave and approximate solvers for optimal efficiencyParallel computing on clusters and multi-core systemsEfield MoM: Parallel and out-of-core boundary integral methodEfield MLFMM: Acceleration technique for full-wave analysis of large-scale problemsEfield MoM/MLFMM-PO Hybrid solverEfield MDMM: Domain decomposition tool for reduced simulation timeEfield MDMM/FEM: Detailed integrated antenna modeling

Efield Frequency-DomainSolver Technology

Efield MLFMM - Parallell and out-of-core multilevel fast multipole solverMRI - Interpolation for frequency-sweeps and multiple RHSImproved integral equation for PEC-dielectric problems combining PMCHWT and Muller formulationsHybrid CFIE-EFIE formulation for efficient inclusion of complex antenna geometries on large platformsWide range of sources: plane waves, edge excitation, RLC circuits, port/waveguide mode

Efield MLFMM Solver features*MLFMM solution time per frequency point w and w/o MRIRCS of UAV with RAM coatings - MLFMM convergence rate w and w/o new dielectric formulationEdge coating

Efield MDMMMulti-domain Multi-method*Efield MDMM - Efficient handling of cavities such as integrated antennas, air intakes and exhaustsThe most efficient solver for each domain (MoM/FEM antenna MLFMM/PO platform)Optimal efficiency of MLFMM by extracting resonant parts such as cavities and small geometrical details which typically leads to slow convergenceIn case of design changes only the modified domains needs to be re-computedReduced simulation time: The SWARM antenna problem solved 8x faster using the MDMM technique

*Typical electromagnetic (EM) scenarios in AeronauticsThunder lightning on full aircraftEMC/EMI with internal cablingLightning strike on jet enginesMore candidates withHigh Intensity Radiated Fields (HIRF)RADAR signature & StealthAntenna Placement & composite materials

*Installed antenna simulation using Efield MLFMMGain pattern at1030MHzAntenna modeled by four monopolesEfield MLFMM simulationNo. elements: 317 956 trianglesNo. unknowns: 476 926 Unknowns

RADAR Cross SectionTechnology initiated in the Defense sectorPAM-CEM/FD in the medium frequency rangePAM-CEM/HF 10 GHz RADAR response of a jet aircraft

*RCS of Predator UAV using Efield MLFMMSurface currents for plane wave excitation with vertical polarization at 3 GHzBistatic RCS 3 GHzNo. elements 872,970Memory req: 10GBSimulation time: 1.1hrs (Opteron 285, 4 cores)

Efield MDMM RCS Analysis*Exterior problemInterior problemInterfacesCavity RCS: Contribution of cavity to total RCS (with exterior coupling taken into account) Perfectly matched RCS: RCS with reflectionless cavityTotal RCS: Complete RCS including cavity and exterior contributionsImproved convergence

E FieldCEM dedicated context featuring Visual-Mesh : CAD data import & cleaning, meshing & tuning (FE surface mesh, FD with refinement areas & non uniform grids)Visual-CEM : full 3D modeling (parts, materials & BC), peripheral boundary conditions (ABC/PML), external plane waves, wired antennas & Cable Networks, T/F output (see below)Visual-Viewer : 2D/3D output (THP, cut planes, surface fields, induced currents, CVO, etc.), time & frequency, 2D polar plots, contour over time, etc.Visual-Process Executive

Graphical User Interface(GUI)CEM dedicated context featuring Visual-Mesh : CAD data import & cleaning, meshing & tuning (FE surface mesh, FD with refinement areas & non uniform grids)Visual-CEM : full 3D modeling (parts, materials & BC), peripheral boundary conditions (ABC/PML), external plane waves, wired antennas & Cable Networks, T/F output (see below)Visual-Viewer : 2D/3D output (THP, cut planes, surface fields, induced currents, CVO, etc.), time & frequency, 2D polar plots, contour over time, etc.Visual-Process Executive

Usefulness of the workshop

Enable to learn simulation software for Antenna Design.To handle final year B.E and M.E projects

Copyright ESI Group, 2009. All rights reserved.

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*In computational electromagnetics it is a well-known truth that there is no single method that can adress all problems of interest. The governing equations are the same but due to computational requirements a wide range of tools have to be used.

The main parameters deciding which method is suitable are the bandwith and electrical size. This is illustrated in the above picture

While Jean-Claude and the PAM-CEM team have focused mainly on the automotive industry and EMC issues we have had a strong focus on aerospace industry with applications in antennas and radar cross-section, RCS

PAM-CEM solvers covers the two extremes whereas Efield completes the range by adding frequency-domain solvers

CEM Solutions is not the only software package consisting of a wide range of solvers but compared to HFSS and CST our solutions are more mature for electrically large problems***