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Initial Problems Pieces. Develop Understanding of Coupling Early Catalog of Expected Waveforms at Circuit Terminals Incorporate into Topological Models. Short-Term Problems Wires and Slots. Obtain useful information quickly – 10 months Develop understanding of coupling mechanisms
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Initial Problems Pieces Develop Understanding of Coupling Early Catalog of Expected Waveforms at Circuit Terminals Incorporate into Topological Models
Short-Term ProblemsWires and Slots • Obtain useful information quickly – 10 months • Develop understanding of coupling mechanisms • Assess influence of wires and slots on waveforms • Catalog waveforms that can be expected at a pin of a digital system
Short-Term ProblemsCascaded Coaxial Cavities • Obtain useful information quickly – 12 months • Develop understanding of coupling mechanisms involving cascaded cavities • Assess influence of cascaded cavities on waveforms • Catalog waveforms that can be expected at the terminus of a chain of cascaded cavities
EffectsofPropagationPathonTransientSignal – Cascaded Cavities
EffectsofPropagationPathonTransientSignal – Cascaded Cavities with Load
Short-Term ProblemsFast Time-Domain Methods Development • Fast time-domain integral equation methods for inhomogeneous material regions • Hybrid circuit theory -- TDIE analysis • TDIE analysis for slowly varying (in time) fields • Accurate TDIE for weak penetration through apertures
Proposed Effort (Year 1): Algorithms and Implementations • Develop PWTD enhanced TDIE solvers with material capability (6 mo.) • Interface PWTD enhanced TDIE solvers with SPICE-like circuit solver (12 mo.) • Develop “low frequency” stable PWTD / TDIE solver (12 mo.) • Hybridize loop/star/tree and time Galerkin schemes (Industry strength implementation)
Proposed Effort (Year 1): Demonstration of Capabilities • Analyze coupling into a nonlinear circuit (amplifier) in a realistic enclosure (12 mo.) • Geometry: Slots, cavities, pins, nonlinear circuitry. • Demonstrates all capabilities of solver • Validation: through comparison to FDTD solution. cavity slot circuitry boards + pins
Short-Term ProblemsFast Frequency-Domain Methods Development • Fast frequency-domain integral equation methods for exterior-to-interior coupling problem – specialization of existing codes • Fast frequency-domain integral equation methods for very low frequencies (for FFT) • Fast hybrid methods -- specialization • Serve as checks of other more specialized analyses
Airborne Transmitter Lightening PEDS Ground-based or ship-board Transmitter EMI Threat to Aircraft Systems Picture from NASA-Langley External Threat Internal Threat • Coupling from other Aircraft Systems • Natural Environmental Effects • (Lightening, Static Electricity) • Man Made Sources External to the aircraft • (High Intensity Radiated Fields - HIRF) • Portable Electronic Devices (PEDS) carried by passengers
Penetration through Loaded Slots and Cracks • Most typical coupling occurs through slots and cracks • Closed form expressions will be developed for various 2D slots and 3D straight slots by analogy to wire scattering • Develop an understanding of good shielding practices and relative levels of penetration among the various slots geometries • Develop methods for equivalent circuit extraction
Coupling though Slots in Loaded Structure • Develop general purpose frequency domain techniques for coupling into loaded geometries • Validation of other techniques
Short-Term ProblemsApplication of EIGER • Obtain useful information quickly – 12 months • Develop understanding of coupling mechanisms involving moderately complex structures • Use as a quick check on more problem-specific analyses • EIGER will also be used for longer-term complex problems
EIGER May Be Used for General-Purpose EM Calculations and Code Validation • EIGER is a general-purpose EM modeling code being developed jointly by U. Houston Navy (SPAWAR) Lawrence Livermore Nat’l Lab Sandia Nat’l Labs • Special purpose codes are likely to be needed to efficiently obtain the desired parameters in some cases. • We anticipate using EIGER to obtain initial results,validate new codes, and perform general EM modeling.
EIGER Takes A “Next Generation” Approach to Computational Electromagnetics Object-oriented philosophy • Maintainability, extendibility, availability Current development efforts: U. Houston, U. Washington, Brigham Young, Virginia Tech • A rich set of features allows treatment of complex problems using appropriate optimal combination of techniques • Applicable to a wide variety of EM problems (antennas, RF, EMI, EMC, RCS, etc.) • Eiger can serve as “computational kernel” for special purpose applications, like FSSBuild, a periodic phased array and FSS analysis interface • High performance computing (HPC) capability incorporated into design
Elements Elements Expansions Expansions Excitation Solvers Generality allows one to select the right treatment for each part of a complex problem ... edge treatment Green’s Func. Excitation Boundary Conditions Solvers Operators aperture coupling rotational symmetry
0.6 m - + 0.36 m 0.4 m MURI-Related ExampleConducting Wire with 50 Loads, Terminated on Interior Walls of an Conducting Box with Two Apertures, Excited by a Voltage Source
A Variety of Boundary Conditions are Required: • Aperture • Conducting surface • Wire • Terminating loads
A Combination of Element, Excitation, and Current Types is Needed Element types: triangles quadrilaterals wires Possible excitation types: interior: voltage source exterior: plane wave Current types: two-sided element, single-sided element, wire element,