[PDF] Spectral Methods For Electromagnetic Propagation And Diffraction eBook

Author : L. B. Felsen
Publisher :
Page : 9 pages
File Size : 13,61 MB
Release : 1990
Category :
ISBN :

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Analysis of source-excited time-harmonic and transient electromagnetic wave propagation in complicated environments, wave scattering by complicated targets, or wave penetration into complex structures generally requires decomposition of the incident field into elementary constituents, tracking each constituent through the environment or past the scatter, and recombining at the observer. The elementary constituents are spectral objects such as plane waves, cylindrical waves, conical waves, modal fields, ray field etc. Under transient conditions, the recombination is conventionally performed first on the time-harmonic constituents, with frequency synthesis performed thereafter, but one may alternatively, by a less conventional approach, employ transient constituents (transient plane or cylindrical waves, etc.) and perform the remaining spatial synthesis thereafter. Viewed from this general perspective, there exists an enormous flexibility in the selection of the spectral objects, and of hybrid combinations, for analysis of a particular propagation or scattering problem. It is the objective of the proposed research to examine the various spectral options in their most fundamental terms, study the relation between them, and then assess which option best addresses a particular propagation or scattering phenomenon. (RRH).

Author : Mireille Levy
Publisher : IET
Page : 360 pages
File Size : 27,71 MB
Release : 2000
Category : Mathematics
ISBN : 9780852967645

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Provides scientists and engineers with a tool for accurate assessment of diffraction and ducting on radio and radar systems. The author gives the mathematical background to parabolic equations modeling and describes simple parabolic equation algorithms before progressing to more advanced topics such as domain truncation, the treatment of impedance boundaries, and the implementation of very fast hybrid methods combining ray-tracing and parabolic equation techniques. The last three chapters are devoted to scattering problems, with application to propagation in urban environments and to radar-cross- section computation. Annotation copyrighted by Book News, Inc., Portland, OR

Author : J.J Stamnes
Publisher : Routledge
Page : 630 pages
File Size : 44,88 MB
Release : 2017-11-13
Category : Science
ISBN : 1351404687

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Using numerous mathematical and numerical techniques of diffraction theory, Waves in Focal Regions: Propagation, Diffraction and Focusing of Light, Sound and Water Waves provides a full and richly illustrated description of waves in focal regions. Unlike most books, the author treats electromagnetic, acoustic, and water waves in one comprehensive volume. After an introductory section, the book describes approximate diffraction theories and efficient numerical methods to study the focusing of various kinds of waves. It then covers the physical interpretation of the theories, their accuracy, and the computational savings obtained, emphasizing uniform asymptotic results that remain valid in the vicinity of shadow boundaries and caustics. The next part deals with the focusing of scalar waves, including thorough theoretical analyses and detailed contour maps of diffraction patterns in focal regions for a variety of different system parameters, such as f-number, Frensel number, aperture shape, amplitude distribution, and wavefront aberration. The author proceeds to explore the diffraction and focusing of electromagnetic waves. First solutions are derived for fields radiated by sources, reflected and refracted at plane interfaces, or diffracted by apertures in plane screens, and then these solutions are applied to study the focusing in homogeneous media and through a plane dielectric interface. In both cases, the author includes many computed results of the electromagnetic field distribution near focus. Presenting both theoretical and experimental results, the following part examines the focusing of sound and water waves by means of zone-plate lenses. The book concludes with a detailed study of the diffraction and focusing of water waves and a comparison of the results of both linear and nonlinear theories with those of experiments.

Author : Igor T. Selezov
Publisher : Springer
Page : 241 pages
File Size : 17,3 MB
Release : 2017-09-15
Category : Technology & Engineering
ISBN : 9789811049224

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This book presents two distinct aspects of wave dynamics – wave propagation and diffraction – with a focus on wave diffraction. The authors apply different mathematical methods to the solution of typical problems in the theory of wave propagation and diffraction and analyze the obtained results. The rigorous diffraction theory distinguishes three approaches: the method of surface currents, where the diffracted field is represented as a superposition of secondary spherical waves emitted by each element (the Huygens–Fresnel principle); the Fourier method; and the separation of variables and Wiener–Hopf transformation method. Chapter 1 presents mathematical methods related to studying the problems of wave diffraction theory, while Chapter 2 deals with spectral methods in the theory of wave propagation, focusing mainly on the Fourier methods to study the Stokes (gravity) waves on the surface of inviscid fluid. Chapter 3 then presents some results of modeling the refraction of surf ace gravity waves on the basis of the ray method, which originates from geometrical optics. Chapter 4 is devoted to the diffraction of surface gravity waves and the final two chapters discuss the diffraction of waves by semi-infinite domains on the basis of method of images and present some results on the problem of propagation of tsunami waves. Lastly, it provides insights into directions for further developing the wave diffraction theory.

Author : Yu. G. Smirnov
Publisher : CRC Press
Page : 127 pages
File Size : 19,11 MB
Release : 2022-03-23
Category : Science
ISBN : 0429610564

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This book covers the latest problems of modern mathematical methods for three-dimensional problems of diffraction by arbitrary conducting screens. This comprehensive study provides an introduction to methods of constructing generalized solutions, elements of potential theory, and other underlying mathematical tools. The problem settings, which turn out to be extremely effective, differ significantly from the known approaches and are based on the original concept of vector spaces 'produced' by Maxwell equations. The formalism of pseudodifferential operators enables to prove uniqueness theorems and the Fredholm property for all problems studied. Readers will gain essential insight into the state-of-the-art technique of investigating three-dimensional problems for closed and unclosed screens based on systems of pseudodifferential equations. A detailed treatment of the properties of their kernels, in particular degenerated, is included. Special attention is given to the study of smoothness of generalized solutions and properties of traces.

Author : George Tyras
Publisher : Academic Press
Page : 385 pages
File Size : 45,34 MB
Release : 2013-10-22
Category : Science
ISBN : 1483220516

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Radiation and Propagation of Electromagnetic Waves serves as a text in electrical engineering or electrophysics. The book discusses the electromagnetic theory; plane electromagnetic waves in homogenous isotropic and anisotropic media; and plane electromagnetic waves in inhomogenous stratified media. The text also describes the spectral representation of elementary electromagnetic sources; the field of a dipole in a stratified medium; and radiation in anisotropic plasma. The properties and the procedures of Green’s function method of solution, axial currents, as well as cylindrical boundaries are also considered. The book further tackles diffraction by cylindrical structures and apertures on cylindrical structures. Students taking electrical engineering or electrophysics will find the book useful.

Author : John M. Jarem
Publisher : CRC Press
Page : 432 pages
File Size : 42,75 MB
Release : 2011-04-26
Category : Science
ISBN : 9781439804223

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The current rapid and complex advancement applications of electromagnetic (EM) and optical systems calls for a much needed update on the computational methods currently in use. Completely revised and reflecting ten years of develoments, this second edition of the bestselling Computational Methods for Electromagnetic and Optical Systems provides the update so desperately needed in this field. Offering a wealth of new material, this second edition begins with scalar wave propagation and analysis techniques, chiral and metamaterials, and photonic band gap structures. It examines Pontying vector and stored energy, as well as energy, group, and phase velocities; reviews k-space state variable formation with applications to anistropic planar systems; and presents full-field rigorous coupled wave analysis of planar diffraction gratings with applications to H-mode, E-mode, crossed gratings, single and multilayered diffraction grating analysis, and diffraction from anistropic gratings. Later chapters highlight spectral techniques and RCWA as applied to the analysis of dynamic wave-mixing in PR materials with induced transmission and reflection gratings and demonstrate the RCWA algorithm to analyze cylindrical and spherical systems using circular, bipolar cylindrical, and spherical coordinates. The book concludes with several RCWA computational case studies involving scattering from spatially inhomogeneous eccentric circular cylinders, solved in bipolar coordinates. Many of these examples apply the complex Poynting theorem or the forwardscattering (optical) theorem to validate numerical solutions by verifying power conservation. Using common computational tools such as Fortran, MATLAB, COMSOL, and RSOFT, the text offers numerous examples to illuminate the material, many of which employ a full-field vector approach to analyze and solve Maxwell’s equations in anisotropic media where a standard wave equation approach is intractable. Designed to introduce novel spectral computational techniques, the book demonstrates the application of these methods to analyze a variety of EM and optical systems.

Author : Hugo E. Hernández-Figueroa
Publisher : John Wiley & Sons
Page : 484 pages
File Size : 49,60 MB
Release : 2013-09-25
Category : Science
ISBN : 3527671536

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This continuation and extension of the successful book "Localized Waves" by the same editors brings together leading researchers in non-diffractive waves to cover the most important results in their field and as such is the first to present the current state. The well-balanced presentation of theory and experiments guides readers through the background of different types of non-diffractive waves, their generation, propagation, and possible applications. The authors include a historical account of the development of the field, and cover different types of non-diffractive waves, including Airy waves and realistic, finite-energy solutions suitable for experimental realization. Apart from basic research, the concepts explained here have promising applications in a wide range of technologies, from wireless communication to acoustics and bio-medical imaging.