Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
Some two-dimensional finite element electromagnetic field solvers are described and tested. For TE and TM modes in homogeneous cylindrical waveguides and monopole modes in homogeneous axisymmetric structures, the solvers find approximate solutions to a weak formulation of the wave equation. Second-order isoparametric lagrangian triangular elements represent the field. For multipole modes in axisymmetric structures, the solver finds approximate solutions to a weak form of the curl-curl formulation of Maxwell's equations. Second-order triangular edge elements represent the radial ([rho]) and axial (z) components of the field, while a second-order lagrangian basis represents the azimuthal ([phi]) component of the field weighted by the radius [rho]. A reduced set of basis functions is employed for elements touching the axis. With this basis the spurious modes of the curl-curl formulation have zero frequency, so spurious modes are easily distinguished from non-static physical modes. Tests on an annular ring, a pillbox and a sphere indicate the solutions converge rapidly as the mesh is refined. Computed eigenvalues with relative errors of less than a few parts per million are obtained. Boundary conditions for symmetric, periodic and symmetric-periodic structures are discussed and included in the field solver. Boundary conditions for structures with inversion symmetry are also discussed. Special corner elements are described and employed to improve the accuracy of cylindrical waveguide and monopole modes with singular fields at sharp corners. The field solver is applied to three problems: (1) cross-field amplifier slow-wave circuits, (2) a detuned disk-loaded waveguide linear accelerator structure and (3) a 90[degrees] overmoded waveguide bend. The detuned accelerator structure is a critical application of this high accuracy field solver. To maintain low long-range wakefields, tight design and manufacturing tolerances are required.
Author: Bruno W. Zotter Publisher: World Scientific ISBN: 9789810226268 Category : Science Languages : en Pages : 440
Book Description
Modern particle accelerators and storage rings, whether used for high-energy physics, synchrotron light sources, or other purposes, require particle beams with the highest possible intensity. In order to achieve this maximum performance, a good understanding of the interaction of the charged particle beams with the surrounding vacuum chamber and other accelerator components is necessary. In the frequency domain, this interaction can be described by impedances, and equivalently by wake fields in the time domain. These need to be known to estimate the thresholds of coherent instabilities, or other collective effects, which limit the achievable beam current. Such considerations have to be taken into account already during the design of such machines, as they limit the choice of materials and the shapes of components required for their operations. The book explains the basic concepts, and the methods which have been used to calculate impedances and wakes. The emphasis is on circular particle accelerators and storage rings, with which the authors are more familiar, but many of these concepts are equally useful in linear accelerators or colliders. Without any pretense of completeness, the most important accelerator components, such as vacuum chambers with bellows and pumping ports, RF and other cavities, single steps, irises and collimators, etc. are described in specialised chapters. Also limitations and restrictions of the impedance and wake field descriptions are discussed. The book is mainly written for physicists working with or on particle accelerators or storage rings, and who want to understand the methods which have been used for such calculations.
Author: Yu Zhu Publisher: John Wiley & Sons ISBN: 0471786373 Category : Science Languages : en Pages : 438
Book Description
This is the first comprehensive monograph that features state-of-the-art multigrid methods for enhancing the modeling versatility, numerical robustness, and computational efficiency of one of the most popular classes of numerical electromagnetic field modeling methods: the method of finite elements. The focus of the publication is the development of robust preconditioners for the iterative solution of electromagnetic field boundary value problems (BVPs) discretized by means of finite methods. Specifically, the authors set forth their own successful attempts to utilize concepts from multigrid and multilevel methods for the effective preconditioning of matrices resulting from the approximation of electromagnetic BVPs using finite methods. Following the authors' careful explanations and step-by-step instruction, readers can duplicate the authors' results and take advantage of today's state-of-the-art multigrid/multilevel preconditioners for finite element-based iterative electromagnetic field solvers. Among the highlights of coverage are: * Application of multigrid, multilevel, and hybrid multigrid/multilevel preconditioners to electromagnetic scattering and radiation problems * Broadband, robust numerical modeling of passive microwave components and circuits * Robust, finite element-based modal analysis of electromagnetic waveguides and cavities * Application of Krylov subspace-based methodologies for reduced-order macromodeling of electromagnetic devices and systems * Finite element modeling of electromagnetic waves in periodic structures The authors provide more than thirty detailed algorithms alongside pseudo-codes to assist readers with practical computer implementation. In addition, each chapter includes an applications section with helpful numerical examples that validate the authors' methodologies and demonstrate their computational efficiency and robustness. This groundbreaking book, with its coverage of an exciting new enabling computer-aided design technology, is an essential reference for computer programmers, designers, and engineers, as well as graduate students in engineering and applied physics.
Author: Giuseppe Pelosi Publisher: Artech House ISBN: 1596933461 Category : Science Languages : en Pages : 311
Book Description
The classic 1998 Artech House book, Quick Finite Elements for Electromagnetic Waves, has now been revised and expanded to bring you up-to-date with the latest developments in the Field. You find brand new discussions on finite elements in 3D, 3D resonant cavities, and 3D waveguide devices. Moreover, the second edition supplies you with MATLAB code, making this resource easier to comprehend and use for your projects in the field. This practical book and accompanying software enables you to quickly and easily work out challenging microwave engineering and high-frequency electromagnetic problems using the finite element method (FEM). Using clear, concise text and dozens of real-world application examples, the book provides a detailed description of FEM implementation, while the software provides the code and tools needed to solve the three major types of EM problems: guided propagation, scattering, and radiation. With this unique book and software set in hand, you can compute the dispersion diagram of arbitrarily shaped inhomogeneous isotropic lossless or lossy guiding structures, analyze E- and H-plane waveguide discontinuities and devices, and understand the reflection from and transmission through simple 2D and 3D inhomogeneous periodic structures. CD-ROM Included! Easy-to-use finite element software contains ready-made MATLAB and FORTRAN source code that you can use immediately to solve a wide range of microwave and EM problems. The package is fully compatible with Internet "freeware, " so you can perform advanced engineering functions without having to purchase expensive pre- and post-processing tools.
Author: Jian-Ming Jin Publisher: John Wiley & Sons ISBN: 1118842022 Category : Science Languages : en Pages : 728
Book Description
A new edition of the leading textbook on the finite element method, incorporating major advancements and further applications in the field of electromagnetics The finite element method (FEM) is a powerful simulation technique used to solve boundary-value problems in a variety of engineering circumstances. It has been widely used for analysis of electromagnetic fields in antennas, radar scattering, RF and microwave engineering, high-speed/high-frequency circuits, wireless communication, electromagnetic compatibility, photonics, remote sensing, biomedical engineering, and space exploration. The Finite Element Method in Electromagnetics, Third Edition explains the method’s processes and techniques in careful, meticulous prose and covers not only essential finite element method theory, but also its latest developments and applications—giving engineers a methodical way to quickly master this very powerful numerical technique for solving practical, often complicated, electromagnetic problems. Featuring over thirty percent new material, the third edition of this essential and comprehensive text now includes: A wider range of applications, including antennas, phased arrays, electric machines, high-frequency circuits, and crystal photonics The finite element analysis of wave propagation, scattering, and radiation in periodic structures The time-domain finite element method for analysis of wideband antennas and transient electromagnetic phenomena Novel domain decomposition techniques for parallel computation and efficient simulation of large-scale problems, such as phased-array antennas and photonic crystals Along with a great many examples, The Finite Element Method in Electromagnetics is an ideal book for engineering students as well as for professionals in the field.
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Author: Eric Michael Nelson
Author: Bruno W. Zotter
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Author: Yu Zhu
Author: Daniel C. Ross
Author: C. J. Reddy
Author: Giuseppe Pelosi
Author: Jian-Ming Jin