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Examination of the Effectiveness of Far-field Mathematical Absorber Reflection Suppression in a CATR Through computational electromagnetic Simulation 11

Examination of the Effectiveness of Far-field Mathematical A...

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11th European Conference on Antennas and Propagation (EUCAP)

作者： Gregson, S. F. Parini, C. G. Newell, A. C. Hindman, G. E. NSI MI Technol LLC Torrance CA 90502 USA Queen Mary Univ London London England

ISBN: (纸本)9788890701870

For a little over a decade now, a measurement and post-processing technique named Mathematical Absorber Reflection Suppression (MARS) has been used successfully to identify and then suppress range multi-path effects in spherical [1, 2, 3, 4], cylindrical [5, 6, 7] & planar [8, 9] near-field antenna measurement systems and far-field [10] and compact antenna test ranges [11] with a detailed theoretical treatment being presented in [12]. Much of this early work concentrated on verification by empirical testing however some corroboration was obtained with the use of computational electromagnetic simulations that considered far-field [13] and subsequently near-field cases [14]. The recent development of a highly accurate computational electromagnetic simulation tool that permits the simulation of "measured" far-field pattern data as obtained from using a compact antenna test range (CATR) [15] has for the first time permitted the careful verification of the far-field MARS technique for a given AUT and CATR combination. For the first time, this paper presents simulated "measured" far-field pattern data in the presence of a large scatterer and then verifies the successful extraction of the scattering artefacts using standard FF-MARS processing. Results are presented and discussed.

关键词： Compact Antenna Test Range computational electromagnetic Mathematical Absorber Reflection Supression Measurement Simulation

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computational electromagnetic Model of a Cylindrical Near-Field Antenna Test System: Examination of Common Measurement Errors and Their Compensation

Computational Electromagnetic Model of a Cylindrical Near-Fi...

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Loughborough Antennas and Propagation Conference (LAPC)

作者： Gregson, S. F. Newell, A. C. Hindman, G. E. NSI MI Technol 19730 Magellan Dr Torrance CA 90502 USA

ISBN: (纸本)9781509007837

This paper presents the results of a new computational electromagnetic simulation of a cylindrical near-field antenna test system. The new plane-wave spectrum representation based simulation allows many of the commonly encountered components within the range uncertainty budget to be included within the model. These terms are: range reflections, random errors and cylindrical measurement truncation. This paper presents the results of simulations that verify the utility of the cylindrical mathematical absorber reflection suppression (C-MARS) technique for compensation of their effects. Although past verifications have been done using experimental techniques this paper, for the first time, corroborates these findings using purely computational methods.

关键词： Cylindrical Near-Field computational electromagnetic Simulation Cylindrical MARS

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Calderon Strategies for the Convolution Quadrature Time-Domain Electric Field Integral Equation

IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION

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IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION 2024年第2期5卷 379-388页

作者： Cordel, Pierrick Dely, Alexandre Merlini, Adrien Andriulli, Francesco P. Politecn Torino Dept Elect & Telecommun I-10129 Turin Italy Thales DMS F-78990 Elancourt France IMT Atlantique Microwave Dept F-29285 Brest France

In this work, we introduce new integral formulations based on the convolution quadrature method for the time-domain modeling of perfectly electrically conducting scatterers that overcome some of the most critical issues of the standard schemes based on the electric field integral equation (EFIE). The standard time-domain EFIE-based approaches typically yield matrices that become increasingly ill-conditioned as the time-step or the mesh discretization density increase and suffer from the well-known DC instability. This work presents solutions to these issues that are based both on new Calderon strategies and quasi-Helmholtz projectors regularizations. In addition, to ensure an efficient computation of the marching-on-in-time, the proposed schemes leverage properties of the Z-transform-involved in the convolution quadrature discretization scheme-when computing the stabilized operators. The two resulting formulations compare favorably with standard, well-established schemes. The properties and practical relevance of these new formulations will be showcased through relevant numerical examples that include canonical geometries and more complex structures.

关键词： Time-domain analysis Convolution Integral equations Standards Electric fields Mathematical models Geometry Boundary element method Calderon preconditioning computational electromagnetic convolution quadrature method EFIE time-domain integral equations

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An Empirical Characterization of Galvanized Steel Ohmic Losses-Application to the Modeling of Large Resonant Structures

IEEE LETTERS ON ELECTROMAGNETIC COMPATIBILITY PRACTICE AND A...

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IEEE LETTERS ON electromagnetic COMPATIBILITY PRACTICE AND APPLICATIONS 2022年第4期4卷 103-107页

作者： Berthoud, Y. Duchamp, J. -M. Niembro-Martin, A. Dreina, E. Ndagijimana, F. Energy Management Schneider Elect Wireless Connect Team F-38000 Grenoble France Univ Grenoble Alpes CNRS Grenoble INP G2ELab F-38000 Grenoble France

This letter deals with the characterization of Ohmic losses induced by galvanized steel in diffuse field environments. It is then used to compute the mean response of electrically large resonant structures using a statistical method called "Power Balance " (PWB). The Ohmic losses are often predominant and, thus, need to be properly modeled for the method to be accurate. It is especially true for galvanized steel, as it induces losses several orders of magnitude greater than those of untreated steel. First, this letter reviews the principle of the method before presenting a new empirical method for evaluating Ohmic losses induced by coated metals such as galvanized steel. Finally, this method is used as a tool to create an accurate PWB model of a 6-cavity configuration, validated by measurements.

关键词： computational electromagnetic Ohmic losses power balance (PWB) propagation statistical analysis

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Advanced Parallel Algorithms in computational electromagnetics

Advanced Parallel Algorithms in Computational Electromagneti...

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作者： Shu Wang University of New Mexico

学位级别：博士

The rapid development of high performance computing has pushed the computational electromagnetic(CEM) towards high accuracy, high fidelity and extreme computational scales. There is a great need for existing CEM solvers to have enhanced parallelism and scaling capability. The purpose of this dissertation is to investigate advanced parallel algorithms for both frequency and time domain solvers. In frequency domain, this work first develop the underpinnings of parallel preconditioning technique and high-order transmission condition in the context of multi-solver scheme. The result is a computing resource-aware and implementation wise compact solver. Then this work targeted at developing efficient algorithms for cases where iteration of simulations, e. g. parameter sweep, is necessary. The proposed platform Green's function method can effectively reduce the turn-around time by exploiting reusable matrices. In time domain, due to the ever-increasing sophistication in EM systems, a typical transient simulation may require many time steps. Most current transient solvers exploit parallelism in spatial domain which it is not trivial to sustain parallel scaling capability in high level. This work, therefore, provided a new perspective in parallelism, parallel-in-time(PIT). The problem is first decomposed based on superposition principle and corresponding effective integration methods are developed. Next, a hybrid parallel scheme, space-time building block method, which is based on reduced order model, is proposed for applications like meta-material simulation. A improved scaling efficiency and 3x speed-up is observed in our work. Finally, PIT is extended to improve scaling efficiency for nonlinear circuit-electromagnetic co-simulations, where 2x better efficiency is achieved by proposed algorithms.

关键词： Domain Decomposition computational electromagnetic Parallel Computing Green's Function Transient Analysis Parallel-in-Time

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Three-dimensional scatterer extraction for ISAR resynthesis

Three-dimensional scatterer extraction for ISAR resynthesis

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IEEE Radar Conference (RadarConf)

作者： Potgieter, Monique Nel, Willie CSIR Def & Secur Pretoria South Africa

ISBN: (纸本)9781728153681

Through the point scatterer theory used in radar imaging, it is well known that discrete scattering points can be used to represent the complex scattering from a target, at a particular aspect angle. The extracted location and amplitude (over aspect angle) of these scattering points can then be used by hardware in the loop systems for target engagement simulations. This paper reports on a three-dimensional discrete scatterer extraction scheme implemented for the purposes of ISAR resynthesis in a digital radio frequency memory (DRFM) target simulation system. This extraction scheme was implemented within the computational electromagnetic product, SigmaHat, which is developed by the Council for Scientific and Industrial Research (CSIR). The algorithm utilises the custom implementation of a reduced grid sampling scheme, Igloo sampling, three-dimensional Backprojection to generate 3D ISAR images and finally a multi-directional derivative peak extraction scheme to extract the discrete scattering centers.

关键词： Discrete scatterer extraction feature extraction ISAR computational electromagnetic three-dimensional extraction scattering centers

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electromagnetic Integral Equations: Insights in Conditioning and Preconditioning

IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION

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IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION 2021年 2卷 1143-1174页

作者： Adrian, Simon B. Dely, Alexandre Consoli, Davide Merlini, Adrien Andriulli, Francesco P. Univ Rostock Fak Informat & Elektrotech D-18051 Rostock Germany Politecn Torino Dept Elect & Telecommun DET I-10129 Turin Italy IMT Atlantique Microwave Dept F-29285 Brest France

Integral equation formulations are a competitive strategy in computational electromagnetics but, lamentably, are often plagued by ill-conditioning and by related numerical instabilities that can jeopardize their effectiveness in several real case scenarios. Luckily, however, it is possible to leverage effective preconditioning and regularization strategies that can cure a large majority of these problems. Not surprisingly, integral equation preconditioning is currently a quite active field of research. To give the reader a propositive overview of the state of the art, this paper will review and discuss the main advancements in the field of integral equation preconditioning in electromagnetics summarizing the strengths and weaknesses of each technique. The contribution will guide the reader through the choices of the right preconditioner for a given application scenario. This will be complemented by new analyses and discussions which will provide a further and more intuitive understanding of the ill-conditioning of the electric field (EFIE), magnetic field (MFIE), and combined field integral equation (CFIE) and of the associated remedies.

关键词： Integral equations Mathematical models electromagnetics Resonant frequency Magnetic domains Linear systems IEEE Sections computational electromagnetic preconditioning EFIE MFIE

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Fast Fourier factorization for differential method and RCWA: a powerful tool for the modeling of non-lamellar metallic diffraction gratings

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OPTICAL AND QUANTUM ELECTRONICS 2020年第2期52卷 1-13页

作者： Mohamad, Habib Essaid, Soukaina Blaize, Sylvain Macias, Demetrio Benech, Pierre Morand, Alain Univ Grenoble Alpes Inst Engn Grenoble INP IMEP LAHCCNRS F-38000 Grenoble France Univ Technol Troyes L2n 12 Rue Marie Curie CS 42060 F-10004 Troyes France Surys 22 Ave Europe F-77607 Bussy St Georges France

The rigorous coupled-wave analysis (RCWA), also known as Fourier modal method, is one of the most popular methods for the modeling of diffraction gratings. It has been proven to be particularly effective for lamellar gratings. However, for non-lamellar metallic gratings, in TM polarization, the differential method (DM) or the RCWA need to be associated with the fast Fourier factorization (FFF) to provide more accurate solutions. In this study, we present the effectiveness of the FFF when it is associated with the DM and the RCWA for different grating's profiles, and we show how to circumvent on the case where the FFF can diverge when the metal permittivity is close to a pure negative real value.

关键词： computational electromagnetic 1D diffraction grating RCWA Differential method Fast Fourier factorization

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Stochastic-Galerkin Finite-Difference Time-Domain for Waves in Random Layered Media

Stochastic-Galerkin Finite-Difference Time-Domain for Waves ...

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IEEE-MTT-S International Conference on Numerical electromagnetic and Multiphysics Modeling and Optimization (NEMO)

作者： Huang, Der-Han Cangellaris, Andreas C. Chen, Xu Univ Illinois Dept Elect & Comp Engn Urbana IL 61820 USA

ISBN: (纸本)9781728169668

The authors introduce a Stochastic Finite-Difference Time Domain solver formulation based on Stochastic Galerkin Method. The solver can calculate the statistics of the wave in time domain, including mean, standard deviation at each time step. The method uses a single simulation of an expanded system, without the need for repeated simulations like Monte Carlo analysis. We demonstrate the method is accurate for computing random total waves in layered media with Gaussian random permittivity and conductivity. We also demonstrate the method for simulating materials with Bernoulli distributed random profiles, which is used to model material that may or may not exist. Results accuracy and computation time compare favorably to Monte Carlo simulations.

关键词： computational electromagnetic finite-difference time-domain (FDTD) uncertainty quantification polynomial chaos uncertainty analysis random media

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The use of SigmaHat for Modelling of Electrically Large Practical Radar Problems

The use of SigmaHat for Modelling of Electrically Large Prac...

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IEEE International Radar Conference (RADAR)

作者： Potgieter, M. Cilliers, J. E. Blaauw, C. CSIR Def & Secur Cluster Pretoria South Africa

ISBN: (纸本)9781728168135

SigmaHat is a computational electromagnetic (CEM) tool developed to solve practical radar and electronic warfare (EW) electromagnetic (EM) scattering from electrically large and electrically very large scenes. The software is an ideal tool for radar and EW engineers to design and investigate various systems as well as gain insight into the underlying scattering mechanisms from complex geometries. This paper demonstrates the capability of SigmaHat as a tool to solve practical radar and EW problems.

关键词： Asymptotic solver computational electromagnetic CEM Electronic Warfare Radar Cross Section Radar Physical Optics Shooting and bouncing rays

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