Fast and Well-Conditioned Integral Equation Solvers for Low-Frequency Electromagnetic Problems PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Fast and Well-Conditioned Integral Equation Solvers for Low-Frequency Electromagnetic Problems PDF full book. Access full book title Fast and Well-Conditioned Integral Equation Solvers for Low-Frequency Electromagnetic Problems by Qin Liu. Download full books in PDF and EPUB format.
Author: Qin Liu
Publisher:
ISBN: 9781361013502
Category :
Languages : en
Pages :
Get Book Here
Book Description
This dissertation, "Fast and Well-conditioned Integral Equation Solvers for Low-frequency Electromagnetic Problems" by Qin, Liu, 刘{274b4d}, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Inspired by the important low frequency applications, such as the integrate circuits, the nano electromagnetic compatibility and quantum optics, several aspects of the computational electromagnetic low-frequency problems in surface integral equation (SIE) are carefully investigated in this dissertation. Firstly a capacitive model is studied that the convergence of the matrix system is co-determined by both the condition of the matrix and the righthand-side excitation. In a current solution, the weighted contributions from different singular vectors are not only decided by the corresponding singular values but also the right-hand side. The convergence of the capacitive problems is guaranteed by the fact that the singular vectors corresponding to the small singular values are not excited under the delta-gap source. The dominant charge currents are enough to capture the capacitive physics. Detailed spectral analysis with right-hand side effect validates the proposed theory. Secondly, in order to overcome the low-frequency inaccuracy problem for open capacitive structures in CMP-EFIE, a perturbed CMP-EFIE is proposed to extract accurate high-order current at low frequencies. Further study of the capacitive problems in CMP-EFIE utilizes a simplified two-term system by removing the contribution from the hypersingular preconditioned term, which captures the correct physics without doing the perturbation steps. The afore-built right-hand side analysis theory is applied here to explain the stability and accuracy of the simplified CMP-EFIE system. Thirdly, a point testing system is constructed to eliminate the nontrivial nullspaces of the static MFIE systems by enforcing extra zero magnetic flux conditions at the testing points locations. The projection of the current solution onto the magnetostatic nullspaces is truncated accordingly, thus the system convergence can be much improved without losing any accuracy. Finally, the electromagnetic solution is obtained from a potential-based integral equation solver, capturing electrostatic physics from the scalar potential formulation and magnetostatic physics from the vector potential formulation. The combination of the two formulations reveals the correct solution and physics at low frequencies. And the equations, formulated with the potential quantities, make it possible to couple with quantum effects theories. The resulting system appears to be a symmetric saddle point problem, where the efficiency of the iterative solver can be well-solved by a typical appropriate constraint preconditioner. The stability and capability of the new system in solving different kinds of electromagnetic problems are validated over a wide range of frequency range. The research topics in this dissertation cover different aspects of low frequency integral equation solvers, aiming at fast, stable, wide-band and accurate integral algorithms. Subjects: Integral equations Electromagnetic fields - Mathematical models
Author: Qin Liu
Publisher:
ISBN: 9781361013502
Category :
Languages : en
Pages :
Get Book Here
Book Description
This dissertation, "Fast and Well-conditioned Integral Equation Solvers for Low-frequency Electromagnetic Problems" by Qin, Liu, 刘{274b4d}, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Inspired by the important low frequency applications, such as the integrate circuits, the nano electromagnetic compatibility and quantum optics, several aspects of the computational electromagnetic low-frequency problems in surface integral equation (SIE) are carefully investigated in this dissertation. Firstly a capacitive model is studied that the convergence of the matrix system is co-determined by both the condition of the matrix and the righthand-side excitation. In a current solution, the weighted contributions from different singular vectors are not only decided by the corresponding singular values but also the right-hand side. The convergence of the capacitive problems is guaranteed by the fact that the singular vectors corresponding to the small singular values are not excited under the delta-gap source. The dominant charge currents are enough to capture the capacitive physics. Detailed spectral analysis with right-hand side effect validates the proposed theory. Secondly, in order to overcome the low-frequency inaccuracy problem for open capacitive structures in CMP-EFIE, a perturbed CMP-EFIE is proposed to extract accurate high-order current at low frequencies. Further study of the capacitive problems in CMP-EFIE utilizes a simplified two-term system by removing the contribution from the hypersingular preconditioned term, which captures the correct physics without doing the perturbation steps. The afore-built right-hand side analysis theory is applied here to explain the stability and accuracy of the simplified CMP-EFIE system. Thirdly, a point testing system is constructed to eliminate the nontrivial nullspaces of the static MFIE systems by enforcing extra zero magnetic flux conditions at the testing points locations. The projection of the current solution onto the magnetostatic nullspaces is truncated accordingly, thus the system convergence can be much improved without losing any accuracy. Finally, the electromagnetic solution is obtained from a potential-based integral equation solver, capturing electrostatic physics from the scalar potential formulation and magnetostatic physics from the vector potential formulation. The combination of the two formulations reveals the correct solution and physics at low frequencies. And the equations, formulated with the potential quantities, make it possible to couple with quantum effects theories. The resulting system appears to be a symmetric saddle point problem, where the efficiency of the iterative solver can be well-solved by a typical appropriate constraint preconditioner. The stability and capability of the new system in solving different kinds of electromagnetic problems are validated over a wide range of frequency range. The research topics in this dissertation cover different aspects of low frequency integral equation solvers, aiming at fast, stable, wide-band and accurate integral algorithms. Subjects: Integral equations Electromagnetic fields - Mathematical models
Author: 刘{274b4d} (Researcher on electrical and electronic engineering)
Publisher:
ISBN:
Category : Electromagnetic fields
Languages : en
Pages : 0
Get Book Here
Book Description
Author: 刘琴
Publisher:
ISBN:
Category : Electromagnetic fields
Languages : en
Pages : 138
Get Book Here
Book Description
Author: Weng Cho Chew
Publisher: Morgan & Claypool Publishers
ISBN: 1598291483
Category : Elastic waves
Languages : en
Pages : 259
Get Book Here
Book Description
Integral Equation Methods for Electromagnetic and Elastic Waves is an outgrowth of several years of work. There have been no recent books on integral equation methods. There are books written on integral equations, but either they have been around for a while, or they were written by mathematicians. Much of the knowledge in integral equation methods still resides in journal papers. With this book, important relevant knowledge for integral equations are consolidated in one place and researchers need only read the pertinent chapters in this book to gain important knowledge needed for integral equation research. Also, learning the fundamentals of linear elastic wave theory does not require a quantum leap for electromagnetic practitioners. Integral equation methods have been around for several decades, and their introduction to electromagnetics has been due to the seminal works of Richmond and Harrington in the 1960s. There was a surge in the interest in this topic in the 1980s (notably the work of Wilton and his coworkers) due to increased computing power. The interest in this area was on the wane when it was demonstrated that differential equation methods, with their sparse matrices, can solve many problems more efficiently than integral equation methods. Recently, due to the advent of fast algorithms, there has been a revival in integral equation methods in electromagnetics. Much of our work in recent years has been in fast algorithms for integral equations, which prompted our interest in integral equation methods. While previously, only tens of thousands of unknowns could be solved by integral equation methods, now, tens of millions of unknowns can be solved with fast algorithms. This has prompted new enthusiasm in integral equation methods. Table of Contents: Introduction to Computational Electromagnetics / Linear Vector Space, Reciprocity, and Energy Conservation / Introduction to Integral Equations / Integral Equations for Penetrable Objects / Low-Frequency Problems in Integral Equations / Dyadic Green's Function for Layered Media and Integral Equations / Fast Inhomogeneous Plane Wave Algorithm for Layered Media / Electromagnetic Wave versus Elastic Wave / Glossary of Acronyms
Author: Ozgur Ergul
Publisher: John Wiley & Sons
ISBN: 1118844912
Category : Science
Languages : en
Pages : 484
Get Book Here
Book Description
The Multilevel Fast Multipole Algorithm (MLFMA) for Solving Large-Scale Computational Electromagnetic Problems provides a detailed and instructional overview of implementing MLFMA. The book: Presents a comprehensive treatment of the MLFMA algorithm, including basic linear algebra concepts, recent developments on the parallel computation, and a number of application examples Covers solutions of electromagnetic problems involving dielectric objects and perfectly-conducting objects Discusses applications including scattering from airborne targets, scattering from red blood cells, radiation from antennas and arrays, metamaterials etc. Is written by authors who have more than 25 years experience on the development and implementation of MLFMA The book will be useful for post-graduate students, researchers, and academics, studying in the areas of computational electromagnetics, numerical analysis, and computer science, and who would like to implement and develop rigorous simulation environments based on MLFMA.
Author: Salvatore Celozzi
Publisher: John Wiley & Sons
ISBN: 0470268476
Category : Technology & Engineering
Languages : en
Pages : 385
Get Book Here
Book Description
The definitive reference on electromagnetic shielding materials, configurations, approaches, and analyses This reference provides a comprehensive survey of options for the reduction of the electromagnetic field levels in prescribed areas. After an introduction and an overview of available materials, it discusses figures of merit for shielding configurations, the shielding effectiveness of stratified media, numerical methods for shielding analyses, apertures in planar metal screens, enclosures, and cable shielding. Up to date and comprehensive, Electromagnetic Shielding: Explores new and innovative techniques in electromagnetic shielding Presents a critical approach to electromagnetic shielding that highlights the limits of formulations based on plane-wave sources Analyzes aspects not normally considered in electromagnetic shielding, such as the effects of the content of the shielding enclosures Includes references at the end of each chapter to facilitate further study The last three chapters discuss frequency-selective shielding, shielding design procedures, and uncommon ways of shielding—areas ripe for further research. This is an authoritative, hands-on resource for practicing telecommunications and electrical engineers, as well as researchers in industry and academia who are involved in the design and analysis of electromagnetic shielding structures.
Author: Mei Song Tong
Publisher: John Wiley & Sons
ISBN: 1119284872
Category : Science
Languages : en
Pages : 528
Get Book Here
Book Description
A comprehensive, step-by-step reference to the Nyström Method for solving Electromagnetic problems using integral equations Computational electromagnetics studies the numerical methods or techniques that solve electromagnetic problems by computer programming. Currently, there are mainly three numerical methods for electromagnetic problems: the finite-difference time-domain (FDTD), finite element method (FEM), and integral equation methods (IEMs). In the IEMs, the method of moments (MoM) is the most widely used method, but much attention is being paid to the Nyström method as another IEM, because it possesses some unique merits which the MoM lacks. This book focuses on that method—providing information on everything that students and professionals working in the field need to know. Written by the top researchers in electromagnetics, this complete reference book is a consolidation of advances made in the use of the Nyström method for solving electromagnetic integral equations. It begins by introducing the fundamentals of the electromagnetic theory and computational electromagnetics, before proceeding to illustrate the advantages unique to the Nyström method through rigorous worked out examples and equations. Key topics include quadrature rules, singularity treatment techniques, applications to conducting and penetrable media, multiphysics electromagnetic problems, time-domain integral equations, inverse scattering problems and incorporation with multilevel fast multiple algorithm. Systematically introduces the fundamental principles, equations, and advantages of the Nyström method for solving electromagnetic problems Features the unique benefits of using the Nyström method through numerical comparisons with other numerical and analytical methods Covers a broad range of application examples that will point the way for future research The Nystrom Method in Electromagnetics is ideal for graduate students, senior undergraduates, and researchers studying engineering electromagnetics, computational methods, and applied mathematics. Practicing engineers and other industry professionals working in engineering electromagnetics and engineering mathematics will also find it to be incredibly helpful.
Author: Kai Yang
Publisher:
ISBN:
Category :
Languages : en
Pages : 328
Get Book Here
Book Description
Novel integral-equation methods for efficiently solving electromagnetic problems that involve more than a single length scale of interest in complex backgrounds are presented. Such multi-scale electromagnetic problems arise because of the interplay of two distinct factors: the structure under study and the background medium. Both can contain material properties (wavelengths/skin depths) and geometrical features at different length scales, which gives rise to four types of multi-scale problems: (1) twoscale, (2) multi-scale structure, (3) multi-scale background, and (4) multi-scale-squared problems, where a single-scale structure resides in a different single-scale background, a multi-scale structure resides in a single-scale background, a single-scale structure resides in a multi-scale background, and a multi-scale structure resides in a multi-scale background, respectively. Electromagnetic problems can be further categorized in terms of the relative values of the length scales that characterize the structure and the background medium as (a) high-frequency, (b) low-frequency, and (c) mixed-frequency problems, where the wavelengths/skin depths in the background medium, the structure's geometrical features or internal wavelengths/skin depths, and a combination of these three factors dictate the field variations on/in the structure, respectively. This dissertation presents several problems arising from geophysical exploration and microwave chemistry that demonstrate the different types of multi-scale problems encountered in electromagnetic analysis and the computational challenges they pose. It also presents novel frequency-domain integral-equation methods with proper Green function kernels for solving these multi-scale problems. These methods avoid meshing the background medium and finding fields in an extended computational domain outside the structure, thereby resolving important complications encountered in type 3 and 4 multi-scale problems that limit alternative methods. Nevertheless, they have been of limited practical use because of their high computational costs and because most of the existing 'fast integral-equation algorithms' are not applicable to complex Green function kernels. This dissertation introduces novel FFT, multigrid, and FFT-truncated multigrid algorithms that reduce the computational costs of frequency-domain integral-equation methods for complex backgrounds and enable the solution of unprecedented type 3 and 4 multi-scale problems. The proposed algorithms are formulated in detail, their computational costs are analyzed theoretically, and their features are demonstrated by solving benchmark and challenging multi-scale problems.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Utkarsh Patel
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Despite vast advancements in computational hardware capabilities, full-wave electromagnetic simulations of many multiscale problems continue to be a daunting task. Multiscale problems are encountered, for example, when modeling interconnects in an integrated circuit or when simulating complex electromagnetic structures. In interconnect problems, the main challenge is to model the multiscale skin effect that develops inside the conductors at high frequency. Similarly, complex electromagnetic structures are multiscale because these surfaces are tens of wavelengths large, while each unit cell often contains subwavelength geometrical features. This thesis presents reduced-order integral equation methods to solve complex multiscale problems. For interconnect problems, it proposes a single-source surface integral equation method to model 2-D and 3-D conductors or dielectrics of arbitrary shape. In this approach, electromagnetic fields inside a conductor or a dielectric object are accurately modeled by a differential surface admittance operator and an equivalent electric current density on the object's surface. Since the proposed method does not use any volumetric unknowns, it is more efficient than volumetric methods encountered in the literature and commercial solvers, which require a fine mesh to model the skin effect. Furthermore, since the proposed approach is single-source, it is more efficient than other surface methods in the literature that require both equivalent electric and magnetic current densities. Numerical results show that the proposed method can be over 100x and 20x faster than commercial FEM solvers for 2-D and 3-D problems, respectively, while consuming significantly lower memory. The proposed surface method for conductors and dielectrics is further generalized to develop the so-called macromodeling technique to simulate complex scatterers. In this technique, a heterogeneous scatterer composed of dielectric and PEC objects is accurately modeled by equivalent electric and magnetic current densities that are introduced on a fictitious surface enclosing the element. The crux of the technique is to solve for unknowns only on the fictitious surface, instead of the scatterers, which results in fewer unknowns. Numerical results show that the proposed macromodeling technique can efficiently simulate electrically large reflectarrays composed of square patches and Jerusalem crosses, that are difficult to simulate even with commercial solvers.
