Scattering by a double wedge and a parallel cylinder
01 Mar 1986-International Journal of Electronics (Taylor & Francis Group)-Vol. 60, Iss: 3, pp 367-380
TL;DR: In this article, a simple technique for solving the problem of an E-polarized plane wave scattered by three objects consisting of two wedges and a cylinder is presented, based on an extension of the Karp and Russek solution for the diffraction by a wide slit.
Abstract: A simple technique for solving the problem of an E-polarized plane wave scattered by three objects consisting of two wedges and a cylinder is presented. The method is based on an extension of the Karp and Russek solution for the diffraction by a wide slit, and is applied here to investigate the transmission coefficient through the aperture of a wide double wedge in the presence of a circular dielectric or conducting cylinder whose axis is parallel to the edges of the two wedges. An improvement in the transmission coefficient is observed in the presence of a dielectric cylinder, whereas a conducting cylinder yields a lower transmission coefficient relative to the case when the cylinder is absent.
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TL;DR: In this paper, the scattering of an electromagnetic plane wave from an arbitrary configuration of parallel circular cylinders is investigated using four different techniques: boundary value type of solution, an iterative scattering procedure, a hybrid approach based on a combination of exact and method of moments solution, and a high-frequency asymptotic approximation.
Abstract: The scattering of an electromagnetic plane wave from an arbitrary configuration of parallel circular cylinders is investigated using four different techniques. The cylinders are made of perfectly conducting or homogeneous dielectric material. These techniques are a boundary value type of solution, an iterative scattering procedure, a hybrid approach based on a combination of exact and method of moments solution, and a high-frequency asymptotic approximation. The analysis is given in detail for the transverse magnetic (TM) polarization, and that for the transverse electric (TE) polarization is outlined. Numerical results are provided to show the major differences between these techniques and the validity of using circular cylinders in modeling composite two-dimensional scatterers.
97 citations
TL;DR: In this paper, the authors presented a method based on the extension of the Clemmow, Karp and Russek solution for diffraction by a wide slit, which was compared with the published work and agreement is fairly good.
Abstract: Diffraction of a plane wave from a geometry which contains an infinite slit in a perfect electric conducting (PEC) plane and a perfectly electromagnetic conductor (PEMC) cylinder is presented. The method is based on the extension of Clemmow, Karp and Russek solution for the diffraction by a wide slit. The results are compared with the published work and agreement is fairly good.
10 citations
Cites background or methods from "Scattering by a double wedge and a ..."
...If the plane wave is restricted such that the incident field does not illuminate the lower faces of the half planes, the total field in the forward direction is given by [38]: E = E + E where E = E + E + E (20)...
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...This technique was used by Clemmow [25] for the diffraction by a wide slit and extended by Elsherbeni and Hamid [26, 27]....
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...The same technique was used by Elsherbeni and Hamid [38]....
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08 Jun 1986
TL;DR: In this article, the scattered field due to a plane wave incident on two parallel multilayered dielectric cylinders is derived using the boundary value approach and an asymptotic solution is also presented in which fictitious line sources located at the cylinder axes are used to account for the multiple interactions.
Abstract: In this paper the scattered field due to a plane wave incident on two parallel multilayered dielectric cylinders is derived using the boundary value approach. An asymptotic solution is also presented in which fictitious line sources located at the cylinder axes are used to account for the multiple interactions. For the sake of simplicity two layered-dielectric cylinders and two dielectridy coated conducting cylinders are investigated, however the solution can be easily extended to many layers as well as to many cylinders.
10 citations
TL;DR: In this article, the diffraction by two conducting sharp wedges with cylindrically capped edges was investigated using a recent asymptotic solution proposed by the authors for the Diffraction by a wide double wedge.
Abstract: The diffraction by two conducting sharp wedges with cylindrically capped edges is investigated using a recent asymptotic solution proposed by the authors for the diffraction by a wide double wedge. An E -polarized plane wave incident at any angle is considered and the cap is assumed to be either a conducting or dielectric cylinder whose axis coincides with the wedge edge and its radius is much less than the separation between the two virtual sharp edges. The effects of the cap radius, permittivity, and wedge angle on the diffraction pattern, transmission coefficient, and edge-edge interaction term are presented. The transmission coefficient of the aperture is increased over the uncapped wedge case for dielectric caps and decreased for conducting caps. Other effects of the caps on the diffraction pattern such as beamwidth, level, and position of the first sidelobe are also investigated.
4 citations
TL;DR: In this article, a rigorous field analysis of the electromagnetic scattering from a perfectly conducting strip loaded with a dielectric cylinder is presented, and the solution is based on a boundary value approach and a high frequency asymptotic technique is also developed for the scattering from an array of loaded strips.
Abstract: A rigorous field analysis of the electromagnetic scattering from a perfectly conducting strip loaded with a dielectric cylinder is presented. The dielectric cylinder is of circular cross-section and the dielectric medium is assumed to be linear, homogeneous, and isotropic. The strip is oriented radially with respect to the center of the cylinder and can be located inside or outside, but touching, the outer boundary of the cylinder. The structure is excited by a plane wave or a line current field and both TM and TE to z excitations are considered. The solution of the scattering from a single loaded strip is based on a boundary value approach and a high frequency asymptotic technique is also developed for the scattering from an array of loaded strips. The validity of this proposed solution is investigated by comparing the numerical results of selected cases with those based on exact and method of moments solutions. Sample numerical results for the scattering from a single loaded strip and an array of loaded...
4 citations
References
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Book•
01 Jun 1961
TL;DR: In this paper, a revised version of the Revised edition of the book has been published, with a new introduction to the concept of plane wave functions and spherical wave functions, as well as a detailed discussion of the properties of these functions.
Abstract: Foreword to the Revised Edition. Preface. Fundamental Concepts. Introduction to Waves. Some Theorems and Concepts. Plane Wave Functions. Cylindrical Wave Functions. Spherical Wave Functions. Perturbational and Variational Techniques. Microwave Networks. Appendix A: Vector Analysis. Appendix B: Complex Permittivities. Appendix C: Fourier Series and Integrals. Appendix D: Bessel Functions. Appendix E: Legendre Functions. Bibliography. Index.
5,655 citations
TL;DR: In this paper, the geometrical theory of diffraction was introduced to account for diffraction by introducing new rays called diffracted rays, which are produced when incident rays hit the aperture edge.
Abstract: Diffraction of a wave by an aperture of any shape in a thin screen is treated by a new method—``the geometrical theory of diffraction.'' This is an extension of geometrical optics which accounts for diffraction by introducing new rays called diffracted rays. They are produced when incident rays hit the aperture edge and they satisfy the ``law of diffraction.'' A field is associated with each ray in a quantitative way, by means of the optical principles of phase variation and energy conservation. In addition ``diffraction coefficients'' are introduced to relate the field on a diffracted ray to that on the corresponding incident ray.By this method a simple formula is obtained for the field diffracted by any aperture. It yields the field in the aperture, the diffraction pattern and the transmission cross section. Explicit formulas and numerical results are given for slits and circular apertures. The accuracy of the results increases as the wavelength decreases, but they are useful for wavelengths even as lar...
389 citations
Book•
01 Apr 1980
TL;DR: In this article, a thorough and clear exposition of the Geometrical Theory of Diffraction (GTD) formulation for vector fields is presented, together with useful formulations that can be readily applied to solve practical engineering problems.
Abstract: The continuous development of the Geometrical Theory of Diffraction (GTD), from its conception in the 1950s, has now established it as a leading analytical technique in the prediction of high-frequency electromagnetic radiation and scattering phenomena. Consequently, there is an increasing demand for research workers and students in electromagnetic waves to be familiar with this technique. In this book they will find a thorough and clear exposition of the GTD formulation for vector fields. It begins by describing the foundations of the theory in canonical problems and then proceeds to develop the method to treat a variety of circumstances. Where applicable, the relationship between GTD and other high-frequency methods, such as aperture field and the physical optics approximation, is stressed throughout the text. The purpose of the book, apart from expounding the GTD method, is to present useful formulations that can be readily applied to solve practical engineering problems. To this end, the final chapter supplies some fully worked examples to demonstrate the practical application of the GTD techniques developed in the earlier chapters.
299 citations
TL;DR: In this paper, the scattering pattern and back-scattering cross-section due to an E-polarized plane wave incident on N circular parallel conducting cylinders in an arbitrary configuration were computed by the boundary value method.
Abstract: The scattering pattern and back-scattering cross-section, due to an E-polarized plane wave incident on N circular parallel conducting cylinders in an arbitrary configuration, is computed by the boundary-value method. The results compare favourably for thin cylinders with an approximate solution based on an extension of the Karp–Russek technique for large separation between any two adjacent cylinders relative to the larger diameter. The results indicate that for broadside incidence and fixed radii and separation of an equi-spaced linear array of cylinders, the maximum back-scattering cross-section increases monotonically with an increasing number of cylinders. On the other hand, for normal incidence and fixed radii, the peak of the maximum back-scattering cross-section occurs at the same separation between the cylinders for any number of cylinders.
103 citations
Book•
09 Feb 2018
TL;DR: In this article, the problem of diffraction of scalar waves by an infinite conducting plane with a slit was investigated, and the authors derived approximate expressions for the near and far fields, taking into account the interaction between the edges, were derived in terms of the well-known solutions for the field produced when an isolated conducting halfplane is excited by a plane wave, and a line source.
Abstract: The problem of diffraction of scalar waves by an infinite conducting plane with a slit is investigated. Approximate expressions for the near and far fields, taking into account the interaction between the edges, are derived in terms of the well‐known solutions for the field produced when an isolated conducting half‐plane is excited by (a) a plane wave, and (b) a line source. Results of numerical calculation are given for the case of a plane wave normally incident on the slit. Twelve values of slit width ranging from 0.96 to 2.5 wavelengths are considered. A comparison of transmission coefficients is given. It is found that the new approximate solution agrees well with the exact solution, and provides a significant correction to the noninteraction solution. The accuracy increases with the slit width, so that the result is useful in the range where interaction cannot well be neglected but where the exact solution converges so slowly that computation is impracticable.
74 citations