Download or read book On the Diffraction of Microwaves by Apertures in an Infinite Plane Conducting Screen Using Static Field Approximations written by Jay L. Hirshfield (2LT, USAF.) and published by . This book was released on 1954 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffraction of Electromagnetic Waves by an Aperture in an Infinite Plane Conducting Screen written by Howard How Chung Chang and published by . This book was released on 1955 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Research National Bureau of Standards written by United States. National Bureau of Standards and published by . This book was released on 1964 with total page 1400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Research written by United States. National Bureau of Standards and published by . This book was released on 1964 with total page 1354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Theory of Diffraction by an Aperture in an Infinite Plane Screen i written by Harold Levine and published by . This book was released on 1948 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The diffraction of a scalar plane wave by an aperture in an infinite plane screen is examined theoretically. The wave function at an arbitrary point in space is expressed in terms of its values in the aperture, and constructed so as to vanish on the screen, in accordance with the assumed boundary condition. An integral equation to determine the aperture field is obtained from the continuity requirement for the normal derivative of the wave function on traversing the plane of the aperture. Utilizing the integral equation (whose solution is generally unobtainable), the amplitude of the diffracted spherical wave at large distances from the aperture is exhibited in a form which is stationary with respect to small variations (relative to the correct values) of the aperture fields arising from a pair of incident waves. This expression is independent of the scale of the aperture fields. The transmission cross section of the aperture for a plane wave is found to be simply related to the diffracted amplitude observed in the direction of incidence. The variational formulation is applied in detail for a wave incident normally on a circular aperture.
Download or read book On the Theory of Electromagnetic Wave Diffraction by an Aperture in an Infinite Plane Conducting Screen written by Harold Levine and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Theory of Diffraction by an Aperture in an Infinite Plane Screen Ii written by Harold Levine and published by . This book was released on 1949 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The diffraction of a scalar plane wave by an aperture in an infinite plane screen is examined theoretically. The wave function at an arbitrary point of space is expressed in terms of the discontinuity in its normal derivative at the screen, where the boundary condition is that of vanishing wave function. An integral equation for the discontinuity in normal derivative (or the residual function which measures its deviation from the simple distribution appropriate to a completely infinite screen) is the result of applying the boundary condition to the space wave function. Utilizing the integral equation (whose solution is generally unobtainable), the diffracted spherical wave amplitude at large distances from the aperture is cast into a form which is stationary with respect to small variations (relative to the correct values) of the residual functions arising from a pair of incident waves. An homogeneous expression for the amplitude is exhibited wherein the part independent of the residual functions defines a Kirchoff approximation. The connection with another stationary form of the amplitude, involving a pair of aperture wave functions, is examined. A variational expression for the plane wave transmission cross section of the aperture is based on the amplitude observed in the direction of incidence. The variational formulation is applied for a wave incident normally on a circular aperture. By comparison with the exact results available for this problem. it appears that use of simple residual functions in the variational formulation yields approximate, yet accurate expressions for the diffracted amplitude and transmission cross section over a wide range of frequencies. (Author).
Download or read book Diffraction by a Periodically Apertured Conducting Screen written by Richard B. Kieburtz and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rigorous solution is presented of the boundary value problem of diffraction of a plane electromagnetic wave by a conducting plane screen containing s doubly periodic array of square apertures. The electric field in a square aperture is evaluated for several values of aperture width. The solution is valid for a range of dimensions which includes the aperture resonance region. The magnitude and phase of the voltage transmission coefficient are evaluated from the aperture field, and are found to exhibit a resonance for ka approximates or equals 1.5 where k is the wave number and a the aperture width. The problem has been formulated in terms of an integral equation, starting from the differentialintegral equation method of Copson. The integral equation is then solved for the case in which the boundaries are periodic over a plane, by use of a periodic Green's function. The solution for the aperture field is obtained as a rapidly convergent series of functions. This solution is valid for normally incident excitation and for aperture spacing less than a wavelength. (Author).
Download or read book Fractal Apertures in Waveguides Conducting Screens and Cavities written by Basudeb Ghosh and published by Springer. This book was released on 2014-06-22 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the design and analysis of fractal apertures in waveguides, conducting screens and cavities using numerical electromagnetics and field-solvers. The aim is to obtain design solutions with improved accuracy for a wide range of applications. To achieve this goal, a few diverse problems are considered. The book is organized with adequate space dedicated for the design and analysis of fractal apertures in waveguides, conducting screens and cavities, microwave/millimeter wave applications followed by detailed case-study problems to infuse better insight and understanding of the subject. Finally, summaries and suggestions are given for future work. Fractal geometries were widely used in electromagnetics, specifically for antennas and frequency selective surfaces (FSS). The self-similarity of fractal geometry gives rise to a multiband response, whereas the space-filling nature of the fractal geometries makes it an efficient element in antenna and FSS unit cell miniaturization. Until now, no efforts were made to study the behavior of these fractal geometries for aperture coupling problems. The aperture coupling problem is an important boundary value problem in electromagnetics and used in waveguide filters and power dividers, slotted ground planes, frequency selective surfaces and metamaterials. The present book is intended to initiate a study of the characteristics of fractal apertures in waveguides, conducting screens and cavities. To perform a unified analysis of these entirely dissimilar problems, the “generalized network formulation of the aperture problems” by Mautz and Harrington was extended to multiple-aperture geometry. The authors consider the problem of coupling between two arbitrary regions coupled together via multiple apertures of arbitrary shape. MATLAB codes were developed for the problems and validated with the results available in the literature as well as through simulations on ANSOFT's HFSS.
Download or read book Diffraction by a Circular Aperture in a Unidirectionally Conducting Screen written by S. R. SESHADRI and published by . This book was released on 1962 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: The diffraction of a normally incident plane electromagnetic wave with wave number k by a circular aperture of rdius a in a unidirectionally conducting plane screen of zero thickness and infinite extent is considered. In the limit of large ka, the ratio of the transmission cross section to the geometrical optics value pi a squared, is found up to the order (ka) to the -3/2 power. A new feature of this problem is that a set of rays in the sense of Keler's geometrical theory of diffraction emanates from the regions of the aperture rim to which the current on the screen is nearly tangential and proceed in all directions. However, for the case of normal incidence, these rays do not contribute to the transmission cross section up to the order (ka) to the -3/2 power. (Author).
Download or read book On the Scalar Diffraction by a Circular Aperture in an Infinite Plane Screen written by Adrianus T. de Hoop and published by . This book was released on 1955 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Physics written by and published by . This book was released on 1967 with total page 1404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffraction of Microwaves by Slits and Elliptical Apertures written by Air Force Cambridge Research Center (U.S.) and published by . This book was released on 1953 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The near-zone field distribution of an infinite slit and of an elliptical hole was investigated experimentally when these apertures were irradiated at normal incidence by a plane monochromatic electromagnetic wave. The field possesses a structure which is a function of the shape and the dimensions of the aperture. The approximate theories of Bekefi and Neugebauer predict the general structure of the field, but fail to describe it exacty. A modification of the theory which effectively reduces the width of the slit by one-quarter wavelength, results in a much better agreement with experiment." --
Download or read book Radio Science written by and published by . This book was released on 1967 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Admittance of a Surface of Periodic Apertures in an Infinite Plane written by William G. Spaulding and published by . This book was released on 1969 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The admittance of a resonant screen illuminated by an electromagnetic wave of arbitrary incidence is investigated. The screen consists of periodic rectangular apertures in an infinite conducting plane. Fourier analysis coupled with Floquet's theorem is used to obtain an expression for admittance as a function of the angle of incidence, the electrical dimensions of the periodic geometry, and a parametric field distribution. Experimental verification of the theory is shown through comparison of numerical results and measurements utilizing the concept of the waveguide simulation of an infinite array. (Author).
Download or read book On the Diffraction of Electromagnetic Waves by Annular Elliptical and Rectangular Apertures written by CHAANG. HUANG and published by . This book was released on 1953 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review is presented of the derivation of the Kirchhoff-type transmission coefficient as given by Levine and Schwinger (Communications on Pure and Applied Math. III, 4: Dec. 1950) for an aperture in an infinite, pefectly conducting plane of infinitesimal thickness with an incident plane electromagnetic wave. The tangential to be equal to that of the known incident magnetic field. With this relationship, the approximate transmission coefficients of annular, elliptical, and rectangular appertures are evaluated for normal incidence. Numerical results are plotted for appropriate dimensions of each aperture.
Download or read book Diffraction of Electromagnetic Waves at Microwave Frequencies written by Jules A. Boucher and published by . This book was released on 1956 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
