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In the first phase of our work, we have concentrated on laying the foundation to develop fast algorithms, including the use of recursive structure like the recursive aggregate interaction matrix algorithm (RAIMA), the nested equivalence principle algorithm (NEPAL), the ray-propagation fast multipole algorithm (RPFMA), and the multi-level fast multipole algorithm (MLFMA). We have also investigated the use of curvilinear patches to build a basic method of moments code where these acceleration techniques can be used later. In the second phase, which is mainly reported on here, we have concentrated on implementing three-dimensional NEPAL on a massively parallel machine, the Connection Machine CM-5, and have been able to obtain some 3D scattering results. In order to understand the parallelization of codes on the Connection Machine, we have also studied the parallelization of 3D finite-difference time-domain (FDTD) code with PML material absorbing boundary condition (ABC). We found that simple algorithms like the FDTD with material ABC can be parallelized very well allowing us to solve within a minute a problem of over a million nodes. In addition, we have studied the use of the fast multipole method and the ray-propagation fast multipole algorithm to expedite matrix-vector multiplication in a conjugate-gradient solution to integral equations of scattering. We find that these methods are faster than LU decomposition for one incident angle, but are slower than LU decomposition when many incident angles are needed as in the monostatic RCS calculations.

The Applied Computational Electromagnetics Society Journal hereinafter known as the ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the-art, and to the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to Re-invent the wheel to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this publication include code validation, performance analysis, and input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output; identification of new applications for electromagnetics modeling codes and techniques; integration of computational electromagnetics techniques with new computer architectures; and correlation of computational parameters with physical mechanisms. Typical papers will represent the computational electromagnetics aspects of research in electrical engineering, physics, or related disciplines. However, papers which represent research in applied computational electromagnetics itself are equally acceptable. (MM)

Under sponsorship from various Department of Defense (DoD) organizations and a cooperative Research and Development Agreement (CRADA) with the U.S. Research Development and Engineering Command, Army Research Laboratory (RDECOM-ARL) HyPerComp has significantly advanced the state of the art of time-domain, and broad band electromagnetic simulations. The TEMPUS (Time-Domain ElectroMagnetic Parallel Unstructured Simulator) environment is a complete self contained code suite that includes computer aided design (CAD) geometry creation and repair unstructured gridding for fell-scale targets with general materials scalable parallel code architecture higher-order accurate discontinuous Galerkin solvers for Maxwell's equations and post processing utilities for solution visualization and exaction of final results like bistatic and monostatic radar cross section (RCS) synthetic aperture radar (SAR) images and high-range-resolution (HRR) profiles. The high-performance TEMPUS environment is well suited for modeling a variety of targets and electromagnetic problems of interest to the U.S. Army such as: 1) high- speed projectiles with subtle surface discontinuities ridges and/or fins 2) ground-based targets such as tanks and scud missile launchers and 3) foliage penetration and ground interaction for target under trees (TUT). Some of the physics-based phenomenological features that govern the electromagnetic response of general targets are: a) specular reflection b) creeping waves c) traveling waves) slow moving surface waves e) edge diffraction f) singular currents at surface discontinuities g) resonating gaps and cavities and h) general material response.

The Applied Computational Electromagnetics Society Journal hereinafter known as the ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the-art, and to the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to "re-invent the wheel" to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this publication include code validation performance analysis, and input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output; identification of new applications for electromagnetics modeling codes and techniques; integration of computational electromagnetics techniques with new computer architectures; and correlation of computational parameters with physical mechanisms.

Partial contents of this conference proceedings include: (1) Moment Method Theory, (2) Waveguides and Microwave Circuits, (3) Time Domain Methods and Applications, (4) EMI/EMC, (5) High Frequency Methods and Codes, (6) Surface Integral Equation Codes and Applications, and (7) Partial Differential Equation Based Methods.

The Applied Computational Electromagnetics Society Journal hereinafter known as the ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the-art, and to the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to 're-invent the wheel' to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this publication include code validation, performance analysis, and input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output; identification of new applications for electromagnetics modeling codes and techniques; integration of computational electromagnetics techniques with new computer architectures; and correlation of computational parameters with physical mechanisms.

A new computational algorithm, the discrete singular convolution (DSC), is introduced for computational electromagnetics. The basic philosophy behind the DSC algorithm for the approximation of functions and their derivatives is studied. Approximations to the delta distribution are constructed as either bandlimited reproducing kernels or approximate reproducing kernels. A systematic procedure is proposed to handle a number of boundary conditions which occur in practical applications. The unified features of the DSC algorithm for solving differential equations are explored from the point of view of the method of weighted residuals. It is demonstrated that different methods of implementation for the present algorithm, such as global, local, Galerkin, collocation, and finite difference, can be deduced from a single starting point. Both the computational bandwidth and the accuracy of the DSC algorithm are shown to be controllable. Three example problems are employed to illustrate the usefulness, test the accuracy and explore the limitation of the DSC algorithm. A Galerkin-induced collocation approach is used for a waveguide analysis in both regular and irregular domains and for electrostatic field estimation via potential functions. Electromagnetic wave propagation in three spatial dimensions is integrated by using a generalized finite difference approach, which becomes a global-finite difference scheme at certain limit of DSC parameters. Numerical experiments indicate that the proposed algorithm is a promising approach for solving problems in electromagnetics.

computational methods for electromagnetics and microwaves 

computational methods for electromagnetics and microwaves 

Partial Contents: On the Use of Bivariate Spline Interpolation of Slot Data in the Design of Slotted Waveguide Arrays; A Technique for Determining Non-Integer Eigenvalues for Solutions of Ordinary Differential Equations; Antenna Modeling and Characterization of a VLF Airborne Dual Trailing Wire Antenna System; Electromagnetic Scattering from Two-Dimensional Composite Objects; and Use of a Stealth Boundary with Finite Difference Frequency Domain Simulations of Simple Antenna Problems.

Partial contents: Finite Elements in Electromagnetics: A Jubilee Review; Compatibility Relations for Time-Domain and Static Electromagnetic Field Problems; The Application of the Finite Element Method in Design of Electric Motors; Three Methods for Evaluation of Frequency-Dependent Resistances and Inductances of Multiconductor Transmission Lines; Numerical Solutions of Wave Propagation in Dispersive and Lossy Transmission Lines; An Improved Network Model for Eddy Current Problems; The Finite Difference Method in Magnetic Field Problems; and A Case Study Comparing the Lossy Wave Equation to the Continuity Equation in Modeling Late-time Fields Associated with Lightning.

Partial contents include: (1) Iterative Solution of Multiple Right Hand Side Matrix Equations for Frequency Domain Monostatic Radar Cross Section Calculations; (2) A FDTD Surface Impedance Boundary Condition Using Z-Transforms; (3) Shipboard HFDF System Simulation; (4) Hybrid MoM/SBR Method to Compute Scattering from a Slot Array Antenna in a Complex Geometry; (5) Effects of Gaps Among Panels in Radio Astronomy Reflector Antennas; (6) Some Experiences in Using NEC2 to Simulate Radiation from Slots on Cylinders; (7) A Kirchhoff Integral Approach for Decimetric Radiowave Propagation in Urban Areas; and (8) On the Bounded Part of the Kernel in the Cylindrical Antenna Integral Equation.

The Research and Engineering Framework (REF) manages data for a variety of design and analysis codes. Each of these different codes has its own data requirements (data model) for input and output. The method that the REF uses to handle these different data models is through the use of a data dictionary. By utilizing the data dictionary, REF users will have the ability to switch between data models thereby transforming the generic REF into a discipline specific design system. This report documents the effort to design and develop a computational electromagnetics (CEM) specific data dictionary for the REF. Types of data covered by this dictionary include: CEM analysis techniques, geometry elements, material properties, excitation information, and observables information. The CEM data dictionary has been developed as a baseline data dictionary for the wide variety of CEM codes available. A developer need only tie his/her application specific code into the REF directly or through a code interface wrappering to access this data dictionary.

MAJOR TOPICS OF THIS CONFERENCE INCLUDE: (1) VISUALIZATION; (2) ADVANCED TIME-DOMAIN METHODS; (3) MODEL REDUCTION METHODS FOR COMPUTATIONAL ELECTROMAGNETICS; (4) COMPUTER SIMULATION OF ANTENNAS; (5) RADIATION PHYSICS; (6) COMPUTATIONAL METHODS FOR INVERSE SCATTERING; (7) WAVELETS AND FRACTALS; (8) FDTD AND FVTD; (9) INTEGRATED CIRCUITS AND PHOTONICS; (10) SIGNAL PROCESSING TECHNIQUES FOR CEM; (11) ANTENNA APPLICATIONS; (12) SCATTERING AND DIFFRACTION; (13) FINITE ELEMENT ANALYSIS; (14) ADVANCES IN TRANSMISSION LINE MATRIX (TLM) MODELING.

Partial contents include: (1) Domain Decomposition Strategies for Solving the Maxwell Equations on Distributed Parallel Architectures; (2) Moment Method Surface Patch and Wire Grid Accuracy in the Computation of Near Fields; (3) Using the FDTD Method to Model the Reflection Coefficient of a Vivaldi Tapered Slot Antenna Fed Through a Planar Balun; (4) Finite-Difference Time-Domain Modeling of Light-Trapping in Solar Cells; (5) Modeling Eddy Currents in Unbounded Structures Using the Impedance Method; and (6) Verification of Software for Electromagnetic Field Analysis Using Models Proposed by Investigation Committees in IEE of Japan.

The Applied Computational Electromagnetics Society (ACES) Journal hereinafter known as the ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the art, and the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to reinvent the wheel to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this publication include code validation, performance analysis, and input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output; identification of new applications for electromagnetics modeling codes and techniques; integration of computational electromagnetics techniques with new computer architectures; and correlation of computational parameters with physical mechanisms.

TABLE OF CONTENTS: A Random Phase Assisted Ray Tracing Technique for Wireless Channel Modeling; Nanocells Intrasystem Interference Realistic Worst Case Analysis for Open Site Personnal Communication Scenarios; Designing Embedded Antennas for Bluetooth Protocol; Analysis and Design of Tapered Meander Line Antennas for Mobile Communications; A Cole-Cole Diagram Representation of Micro strip Structure; Enhancement of Numerical Computation Methods Useful for Radio Communication Antenna Systems; Time and Frequency Domain Wave Propagators; Ray Tracing Techniques for Mobile Communications; On the Feasibility of the Multipath Fingerprint Method for Location Finding in Urban Environments; and New Designs for Dual Band Antennas for Satellite Mobile Communications Handsets.

This report summarizes the scientific progress on the research grant Application of Model-Based Signal Processing Methods to Computational Electromagnetics Simulators during the period 1 December 1998 - 30 November 1999. Progress on model-based extrapolation and interpolation of complex radiation and scattering data in frequency and aspect is described.

This report summarizes the scientific progress on the research grant Application of Model-Based Signal Processing Methods to Computational Electromagnetics Simulators during the period 1 December 1998 - 30 November 1999. Progress on model-based extrapolation and interpolation of complex radiation and scattering data in frequency and aspect is described.

The author, as part of an internship under the Joint Educational Opportunities for Minorities (JEOM) Program at Naval Air Warfare Center Weapons Division (NAWCWD), China Lake, California, has devised models and methods for the solution of certain frequently recurring problems in electrical engineering. Starting with fundamental equations relating to line charges, the author utilizes the well-known method of moments to model single strip charges, multiple strip charges in various geometrical configurations, and a charged square cylinder excited by an incidental plane wave. Finally, the author considers the problem of calculating the current along a thin-wire antenna.

The author, as part of an internship under the Joint Educational Opportunities for Minorities (JEOM) Program at Naval Air Warfare Center Weapons Division (NAWCWD), China Lake, California, has devised models and methods for the solution of certain frequently recurring problems in electrical engineering. Starting with fundamental equations relating to line charges, the author utilizes the well-known method of moments to model single strip charges, multiple strip charges in various geometrical configurations, and a charged square cylinder excited by an incidental plane wave. Finally, the author considers the problem of calculating the current along a thin-wire antenna.

Git bundles for all repositories under https://git.acem.ece.illinois.edu/ as of 2023-12-12 19:22 UTC. Retrieved with Git 2.1.4 using git clone --mirror $REPOURL $TMPCLONEDIR and GIT_DIR=$TMPCLONEDIR git bundle create $BUNDLENAME --all

A wavelet-collocation scheme, constructed from the discrete singular convolution (DSC) is introduced for computational electromagnetics. The basic philosophy behind the DSC algorithm is studied. Four test problems, including waveguide analysis in both regular and irregular domains, electromagnetic wave scattering, electrostatic field estimation via potential functions, and electromagnetic wave propagation in three spatial dimensions, are employed to illustrate the usefulness, test the accuracy and explore the limitation of the wavelet algorithm. Computational accuracy of the wavelet algorithm is shown to be controllable and is compared with a standard approach. Numerical experiments indicate that the proposed wavelet algorithm is a promising approach for solving problems in electromagnetics.

The Applied Computational Electromagnetics Society Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the-art, and to the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to "re-invent the wheel" to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this publication include code validation, performance analysis, and input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output; identification of new applications for electromagnetics modeling codes and techniques; integration of computational electromagnetics techniques with new computer architectures; and correlation of computational parameters with physical mechanisms. (MM)

This investigation applied parallel processing techniques to a computational electromagnetic code to see if high performance computing can improve the utility and efficiency of techniques used in ship electromagnetic designs. Efficient parallel matrix filling, factoring, and solving routines were developed, implemented, and evaluated. Several techniques for mapping the matrix columns onto the processors were also implemented and evaluated. This report lists several benefits that have resulted, or will result, from work done on this Independent Exploratory Development (IED) project.

Significant progress has been attained in this area: we have developed an algorithm for automatic ansatz generation, and have demonstrated our overall algorithm by obtaining solutions involving tens of ansatz. An addition of Pade approximation has lead to results of machine precision in short computational times. In the last year's work, in particular, multiple scattering algorithms were developed which can compute high-order high frequency solution in 0 (1) operations for configurations giving rise to (a) multiple scattering of fields diffracted at shadow boundaries, as well as (b) multiple scattering withing single non-convex bodies. Very recent results include 0 (1) solvers for (c) three-dimensional problems which can evaluate in a couple of hours, and in single processors, scattering by objects much larger than the largest that could be tackled by other methods, even by means of large supercomputers. In detail, using our high-frequency method we have produced preliminary three-dimensional results for a spherical scatterer of radius $a$. In these preliminary examples we have demonstrated computational times that do not change significantly, with essential fixed accuracies, when the frequency increases.

CONTENTS: Analysis of the Finite Element Radiation Model Cone for Antenna Modeling; Accuracy of the Finite Element Method with Second Order Absorbing Boundary Conditions for the Solution of Aperture Radiation Problems; The FEMAX Finite Element Package for Computing Three dimensional Electromagnetic Fields; A Moment Method Formulation for The Analysis of Wire Antennas Attached to Arbitrary Conducting Bodies Defined by Parametric Surfaces; A Posteriori Error Estimates for Two Dimensional Electromagnetic Field Computations: Boundary Elements and Finite Elements; Modelling of an Arbitrarily Oriented Mobile Telephone Handset in the Finite Difference Time Domain Field Computation Method; A Magnetic Field Iterative Technique for Improving High Frequency Prediction Methods; Modeling of Remote Field Eddy Current Transient Phenomena; and Letter From the Editor: Duncan Baker

CONTENTS: Analysis of the Finite Element Radiation Model Cone for Antenna Modeling; Accuracy of the Finite Element Method with Second Order Absorbing Boundary Conditions for the Solution of Aperture Radiation Problems; The FEMAX Finite Element Package for Computing Three dimensional Electromagnetic Fields; A Moment Method Formulation for The Analysis of Wire Antennas Attached to Arbitrary Conducting Bodies Defined by Parametric Surfaces; A Posteriori Error Estimates for Two Dimensional Electromagnetic Field Computations: Boundary Elements and Finite Elements; Modelling of an Arbitrarily Oriented Mobile Telephone Handset in the Finite Difference Time Domain Field Computation Method; A Magnetic Field Iterative Technique for Improving High Frequency Prediction Methods; Modeling of Remote Field Eddy Current Transient Phenomena; and Letter From the Editor: Duncan Baker

CONTENTS: Analysis of the Finite Element Radiation Model Cone for Antenna Modeling; Accuracy of the Finite Element Method with Second Order Absorbing Boundary Conditions for the Solution of Aperture Radiation Problems; The FEMAX Finite Element Package for Computing Three dimensional Electromagnetic Fields; A Moment Method Formulation for The Analysis of Wire Antennas Attached to Arbitrary Conducting Bodies Defined by Parametric Surfaces; A Posteriori Error Estimates for Two Dimensional Electromagnetic Field Computations: Boundary Elements and Finite Elements; Modelling of an Arbitrarily Oriented Mobile Telephone Handset in the Finite Difference Time Domain Field Computation Method; A Magnetic Field Iterative Technique for Improving High Frequency Prediction Methods; Modeling of Remote Field Eddy Current Transient Phenomena; and Letter From the Editor: Duncan Baker

The work performed under this effort has resulted in development of variety of important computational-electromagnetics tools enabling efficient application to problems involving small geometric anomalies and associated uncertainty evaluation, including: (1) Issues related to highly efficient implementations of integral EM approaches suitable for extension to high-performance parallel solvers; (2) Surface repair and representation of openings and surface variabilities and methodologies for surface repair of highly-damaged or highly-inaccurate geometry representations; (3) Consideration of issues related to uncertainty quantification for both continuous and discrete random variables, with special attention to the context of EMC/EMI, and development of adaptive stochastic collocation and reduced order modelling methods; and (4) Development of integral-equation solvers for electromagnetic scattering by wire antennas and open surfaces, with attention to solution singularities, pseudo-differential character of the integral operators, and associated spectral distributions and required numbers of GMRES iterations.

This work has given rise to significant advances in areas of mathematics and scientific computing closely related to some of the most important scientific and technology areas of our day. The time-domain solvers resulting from this effort hold a promise to raise the bar in time-domain solution of PDEs. The resulting Green function methods have provided a solution to the century-old Wood anomaly problem for the periodic Green function. Work on integral equations and solvers, in turn, has given rise to highly accurate solutions for some of the most challenging scattering problems in science and engineering.

This work has given rise to significant advances in areas of mathematics and scientific computing closely related to some of the most important scientific and technology areas of our day. The time-domain solvers resulting from this effort hold a promise to raise the bar in time-domain solution of PDEs. The resulting Green function methods have provided a solution to the century-old Wood anomaly problem for the periodic Green function. Work on integral equations and solvers, in turn, has given rise to highly accurate solutions for some of the most challenging scattering problems in science and engineering.

This work has given rise to significant advances in areas of mathematics and scientific computing closely related to some of the most important scientific and technology areas of our day. The time-domain solvers resulting from this effort hold a promise to raise the bar in time-domain solution of PDEs. The resulting Green function methods have provided a solution to the century-old Wood anomaly problem for the periodic Green function. Work on integral equations and solvers, in turn, has given rise to highly accurate solutions for some of the most challenging scattering problems in science and engineering.

The report documents information presented at the 14th Annual Review of Progress in Applied Computational Electromagnetics. The conference held 16-20 March 98 at the Naval Postgraduate School, Monterey, CA. The purpose of the conference is to bring together scientists and engineers in Electromagnetism to report the most resent results and to simulate new disciplinary activity. One of the highlights of the symposium was a series of articles on such topics as Applied Computational Electromagnetics (CEM) analysis and application within an engineering environment. The report also covers important issues related to finite difference time domain applications. The report, in addition, greatly focuses on application of Analytic and Computational methods to the modeling of electromagnetic materials.

The report documents information presented at the 14th Annual Review of Progress in Applied Computational Electromagnetics. The conference held 16-20 March 98 at the Naval Postgraduate School, Monterey, CA. The purpose of the conference is to bring together scientists and engineers in Electromagnetism to report the most resent results and to simulate new disciplinary activity. One of the highlights of the symposium was a series of articles on such topics as Applied Computational Electromagnetics (CEM) analysis and application within an engineering environment. The report also covers important issues related to finite difference time domain applications. The report, in addition, greatly focuses on application of Analytic and Computational methods to the modeling of electromagnetic materials.

Partial table of contents: Computational Simulation of Electric Fields Surrounding Power Transmission and Distribution Line; Comparison of Electromagnetic Response in Time and Frequency Domains; Validation of the Numerical Electromagnetics Code (NEC) for Antenna Wire Elements in Proximity to Earth; An Integrated Environment for the Numerical Modeling of Communication Antennas Based on Relational Databases; An Application of the Hybrid Moment Method/Green's Function Technique to the Optimization of Resistive Strips; On the Convergence of the Method of Moments, the Boundary-Residual Method, and the Point-Matching Method with a Rigorously Convergent Formulation of the Point- Matching Method; Solution of Team Benchmark Problem 9 Handling Velocity Effects with Variable Conductivity.

For earth observation, microwave remote sensing has been a useful technology that provides sensing capability of earth terrain with wide coverage. Images from satellite based Synthetic Aperture Radar (SAR) are acquired to provide ground information about various types of earth terrain sensed (such as vegetation, farm, urban area, sea ice and snow covered land, etc). In order to interpret these SAR images correctly, it is necessary to understand how microwave interacts with these earth media.

Partial contents: 3B Splines In the Integral Equation Solution for Scattering from Bodies of Revolution; Electromagnetic Properties of a Chiral Plasma Medium; MTRT - A Modified Transverse Resonance Technique; Effect of the Magnetic Anisotrophy on the Characteristics of Microstrip Antennas with Several Layers; Dispersive Analysis of Circular Cylindrical Microstrips and Backed Slotlines; Finite Element Analysis and Evaluation of Electromagnetic Fields Generated by Atmospheric Discharges; Point Matched Time Domain Finite Element Method Applied to MultiConductor Electromagnetic Transients Analysis; Error Estimators In Self Adaptive Finite Element Field Calculation; Transient Voltage and Electric Field Distributions in Air Core Reactors; Calculation of Electric Field Created by Transmission Lines, by 3D-FE Method Using Complex Electric Scalar Potential; Adaptive Finite Element Mesh Refinement and 'a posteriori' Error Estimation Procedures for Electromagnetic Field Computation; Limitations of the Conventional Methods of Force and Torque Prediction; Comparison of Convergence Rates of Edge and Nodal Finite Elements for Magnetostatic Problems; Finite Element Simulation of an Out of Phase Synchronization of a Synchronous Machine; A 3D Finite Element Computation of Stator End winding Leakage Inductance and Forces at Steady State Operating Conditions in Large Hydrogenerators; Improving the Charge Simulation Method for the Computation of High Voltage Electric Fields with Efficient Least Squares Techniques; A Hybrid Finite Differences and Charge Simulation Method for the Computation of High Voltage Electric Fields; Finite Element Modeling of Electrical Machines by Simultaneous Resolution of Fields and Electric Circuits Equations; and Shape Design Optimization of Power Frequency Electromagnetic Devices Using Numerical Method

Contents include the following articles: (1) Predicting MoM Error Currents by Inverse Application of Residual E-Fields, (2) On the Iteration of Surface Currents and the Magnetic Field Integral Equation, (3) Modeling of Low-Gain Antennas on Aircraft Using APATCH, (4) A Novel Spatial Images Technique for the Analysis of Cavity Backed Antennas, (5) Efficient Solution of Linear Systems in Microwave Numerical Methods, and (6) Parallel Implementation of Galerkin Technique in Large-Scale Electromagnetic Problems.

Contents include the following articles: (1) Predicting MoM Error Currents by Inverse Application of Residual E-Fields, (2) On the Iteration of Surface Currents and the Magnetic Field Integral Equation, (3) Modeling of Low-Gain Antennas on Aircraft Using APATCH, (4) A Novel Spatial Images Technique for the Analysis of Cavity Backed Antennas, (5) Efficient Solution of Linear Systems in Microwave Numerical Methods, and (6) Parallel Implementation of Galerkin Technique in Large-Scale Electromagnetic Problems.

At this annual conference session were held pertaining to the following topics: Scattering; Electromagnetic Modeling; Antennas Near Ground; Applications of Computer Electromagnetic Modeling; NEC-2 and Personal Computer Code Applications; Input - Output Issues; Code Development; Antenna Modeling. Keywords: Perturbations, Small metal gaps, Electromagnetic scattering, Vertical monopoles, Finite element analysis, Electromagnetic codes, Wideband antennas.

Contents: Using Advanced Artificial Intelligence to Create Analysis Plans for Cosite Electromagnetic Interference Problems; Development of GEMCOP, an Expert System for GEMACS and GAUGE; MMP-3D: A Package for Computation of 3D Electromagnetic Fields on PCs and Workstations; Automation of the Geometry data for the NEC and the ESP Using the Super-3D; Iterative Moment Method in Scattering Problems; The Spectral Iteration Technique (SIT) Applied to 3D homogeneous Dielectric Scatterers; Some Modifications of the Numerical Electromagnetics Code and Their Effects; A Special Purpose Computer for the Time Domain Advance of Maxwell's Equation; Electromagnetic Propagation on an Unstructured Finite Element Grid; Analysis of Radar Absorbent Material (RAM) coated HF Wire Rope Antennas Using the TLM Method; Analysis of Waveguide-Fed Thick-Walled Slot Radiator with Parasitic Wires; Analysis of Electromagnetic Interference Effects in Spacecraft Generated by Electrostatic Discharges Using the Method of Moments; The Effect of the Ground Plane on the Log-Periodic Dipole Antenna; MF-Transmitting Antenna Combined with High Grounded Supporting Masts; Characterization of a High-Frequency Vertical Half Rhombic; A Finite Element/ Boundary Integral Equation Approach to the Accurate Prediction of Radar Cross Section; and A Hybrid Asymptotic-Modal Analysis of the EM Scattering by Open- Ended S-Shaped Rectangular Waveguide Cavities. (JHD)

Contents: Using Advanced Artificial Intelligence to Create Analysis Plans for Cosite Electromagnetic Interference Problems; Development of GEMCOP, an Expert System for GEMACS and GAUGE; MMP-3D: A Package for Computation of 3D Electromagnetic Fields on PCs and Workstations; Automation of the Geometry data for the NEC and the ESP Using the Super-3D; Iterative Moment Method in Scattering Problems; The Spectral Iteration Technique (SIT) Applied to 3D homogeneous Dielectric Scatterers; Some Modifications of the Numerical Electromagnetics Code and Their Effects; A Special Purpose Computer for the Time Domain Advance of Maxwell's Equation; Electromagnetic Propagation on an Unstructured Finite Element Grid; Analysis of Radar Absorbent Material (RAM) coated HF Wire Rope Antennas Using the TLM Method; Analysis of Waveguide-Fed Thick-Walled Slot Radiator with Parasitic Wires; Analysis of Electromagnetic Interference Effects in Spacecraft Generated by Electrostatic Discharges Using the Method of Moments; The Effect of the Ground Plane on the Log-Periodic Dipole Antenna; MF-Transmitting Antenna Combined with High Grounded Supporting Masts; Characterization of a High-Frequency Vertical Half Rhombic; A Finite Element/ Boundary Integral Equation Approach to the Accurate Prediction of Radar Cross Section; and A Hybrid Asymptotic-Modal Analysis of the EM Scattering by Open- Ended S-Shaped Rectangular Waveguide Cavities. (JHD)

Contents: Using Advanced Artificial Intelligence to Create Analysis Plans for Cosite Electromagnetic Interference Problems; Development of GEMCOP, an Expert System for GEMACS and GAUGE; MMP-3D: A Package for Computation of 3D Electromagnetic Fields on PCs and Workstations; Automation of the Geometry data for the NEC and the ESP Using the Super-3D; Iterative Moment Method in Scattering Problems; The Spectral Iteration Technique (SIT) Applied to 3D homogeneous Dielectric Scatterers; Some Modifications of the Numerical Electromagnetics Code and Their Effects; A Special Purpose Computer for the Time Domain Advance of Maxwell's Equation; Electromagnetic Propagation on an Unstructured Finite Element Grid; Analysis of Radar Absorbent Material (RAM) coated HF Wire Rope Antennas Using the TLM Method; Analysis of Waveguide-Fed Thick-Walled Slot Radiator with Parasitic Wires; Analysis of Electromagnetic Interference Effects in Spacecraft Generated by Electrostatic Discharges Using the Method of Moments; The Effect of the Ground Plane on the Log-Periodic Dipole Antenna; MF-Transmitting Antenna Combined with High Grounded Supporting Masts; Characterization of a High-Frequency Vertical Half Rhombic; A Finite Element/ Boundary Integral Equation Approach to the Accurate Prediction of Radar Cross Section; and A Hybrid Asymptotic-Modal Analysis of the EM Scattering by Open- Ended S-Shaped Rectangular Waveguide Cavities. (JHD)

The Applied Computational Electromagnetics Society (ACES) Journal hereinafter known as the ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the art, and the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to reinvent the wheel to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this publication include code validation, performance analysis, and input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output; identification of new applications for electromagnetics modeling codes and techniques; integration of computational electromagnetics techniques with new computer architectures; and correlation of computational parameters with physical mechanisms.

This report summarizes the scientific progress on the research grant "Application of Model-Based Signal Processing Methods to Computational Electromagnetics Simulators" during the period 1 December 1997 - 30 November 1998. Progress on model-based frequency extrapolation of antenna radiation patterns on complex platforms and extraction of sparse representation of antenna radiation and coupling data is described.

The overall work in the proposed areas for the duration of this effort, through November 2010, is detailed in what follows. In particular, our efforts gave rise to 1) Volumetric propagation and scattering solvers for propagation through thousand of kilometers of realistic three-dimensional atmospheres (completed in 2009); 2) Development of high-order solvers, which do not suffer from restrictive CFL conditions, for solution of time-dependent wave-propagation problems in inhomogeneous media; 3) Electromagnetic integral solvers for open surfaces in three dimensions, with applicability to design of reflectarray antennas and negative-index materials; 4) Fast, high-order solvers for wire antenna problems; and 5) Solvers for general PDE problems which, not based on use of either finite elements or finite differences use the continuation method instead, and have been shown to lead to unconditionally stable numerics for a wide range of realistic PDE problems.

—Computational electromagnetic (CEM) involves using numerical methods to solve real-life electromagnetic problems. Over the years, a great number of CEM tools have been developed to simulate and to analyze electromagnetic systems. This has been made possible due to the numerous contributions from several institutions, universities, and industries around the world. This paper provides a brief introduction to CEM.

The numerical approximation of Maxwell’s equations, computational electromagnetics (CEM), has emerged as a crucial enabling technology for radio-frequency, microwave, and wireless engineering. The three most popular “full-wave” methods – the Finite Difference Time Domain method, the Method of Moments, and the Finite Element Method – are introduced in this book by way of one- or two-dimensional problems. Commercial or public domain codes implementing these methods are then applied to complex, real-world engineering problems, and a careful analysis of the reliability of the results obtained is performed, along with a discussion of the many pitfalls that can result in inaccurate and misleading solutions. The book will empower readers to become discerning users of CEM software, with an understanding of the underlying methods, and confidence in the results obtained. It also introduces readers to the art of code development. This book has a dedicated website making available a number of MATLABscripts, implementing much of the theory discussed, and including additional material on the practical applications of CEM. Suitable for senior undergraduate and graduate students taking courses on CEM, this would also be a valuable reference book for practicing engineers in the industry.

The numerical approximation of Maxwell’s equations, computational electromagnetics (CEM), has emerged as a crucial enabling technology for radio-frequency, microwave, and wireless engineering. The three most popular “full-wave” methods – the Finite Difference Time Domain method, the Method of Moments, and the Finite Element Method – are introduced in this book by way of one- or two-dimensional problems. Commercial or public domain codes implementing these methods are then applied to complex, real-world engineering problems, and a careful analysis of the reliability of the results obtained is performed, along with a discussion of the many pitfalls that can result in inaccurate and misleading solutions. The book will empower readers to become discerning users of CEM software, with an understanding of the underlying methods, and confidence in the results obtained. It also introduces readers to the art of code development. This book has a dedicated website making available a number of MATLABscripts, implementing much of the theory discussed, and including additional material on the practical applications of CEM. Suitable for senior undergraduate and graduate students taking courses on CEM, this would also be a valuable reference book for practicing engineers in the industry.