The generalized Fresnel integral serves as a canonical function for the uniform ray field representation of several high‐frequency diffraction mechanisms. In this article, an example of application of this canonical function is examined, which is concerned with the diffraction at a plane angular sector with soft boundary conditions on its faces. Closed‐form expressions for computing this canonical function are presented, and it is shown that the approximate formulation adopted herein is accurate and very fast to calculate. © 1995 John Wiley & Sons, Inc. Copyright © 1995 Wiley Periodicals, Inc., A Wiley Company

A high-frequency analysis of the scattered field at a plane angular sector is presented, for the scalar case in which hard boundary conditions are imposed on the two faces. In this formulation, the ordinary UTD field is augmented by uniform vertex diffraction contributions that provide the compensation of the UTD ray field when the first order diffraction points disappear from the tip. Furthermore, an expression of the doubly diffracted rays from the two edges is derived, that provides a uniform description of the total field at the ordinary double diffraction transition regions, including their possible overlapping. Moreover, a new transition function is introduced, which uniformly describes the transition field between doubly diffracted and vertex rays, that occurs when the double diffraction points merge in the tip. In spite of the complication of the physical mechanism, the final solution is simple and easy to implement. © 1996 Journal of Electromagnetic Waves and Applications. All right reserved.

A Floquet waves (FW) representation is used to efficiently calculate the active free-space Green's function. The representation interprets the radiation of a finite phased array as a superposition of FW distributions on the global aperture of the array. The Green's function of an array of dipoles which is truncated in one dimension and infinite in the other is formulated. The dipoles are considered of uniform amplitude and linearly phased for including a scan beam description. By invoking the locality of the high-frequency phenomena, the actual finite distribution may be treated by using local edges.

A truncated Floquet wave (TFW) formulation has been presented previously for the potential of a right-angle sectorial planar phased array of directed dipoles. In this paper, we perform an asymptotic evaluation of the spectral wavenumber integrals, uniformly valid in the vicinity of the vertex and of the shadow boundary of any FW or edge-diffracted wave species.

Two leading high frequency theories have provided very effective tools for engineering purposes namely the geometrical theory of diffraction (GTD) especially in its uniform extension (UTD) and the physical theory of diffraction (PTD). An incremental theory of diffraction has been developed which provides a unified framework for describing high frequency phenomena. The electromagnetic scattering from planar structures is investigated in order to demonstrate the validity of the incremental theory of diffraction (ITD).

A double line integral representation of the mutual coupling between openended waveguides of arbitrary cross section is presented, which is useful to speed up calculations inside the framework of a Galerkin method of moments. © 1997 IEEE.

This paper deals with the derivation and physical interpretation of a uniform high-frequency Green's function for a planar right-angle sectoral phased array of dipoles. This high-frequency Green's function represents the basic constituent for the full-wave description of electromagnetic radiation from rectangular periodic arrays and scattering from rectangular periodic structures. The field obtained by direct summation over the contributions from the individual radiators is restructured into a double spectral integral whose high-frequency asymptotic reduction yields a series of propagating and evanescent Floquet waves (FWs) together with corresponding FW-modulated diffracted fields, which arise from FW scattering at the array edges and vertex. Emphasis is given to the analysis and physical interpretation of the vertex diffracted rays. The locally uniform asymptotics governing this phenomenology is physically appealing, numerically accurate, and efficient, owing to the rapid convergence of both the FW series and the series of corresponding FW-modulated diffracted fields away from the array plane. A sample calculation is included to demonstrate the accuracy of the asymptotic algorithm.

A line integral representation of the Kirchhoff-type aperture integration is derived for an open-ended waveguide with arbitrary cross section, excited by an arbitrary mode. The problem is formulated by taking advantage of the equivalence between the radiation of the aperture and the radiation of the modal currents along the semi-infinite waveguide walls.

A high-frequency description of the scattering from complex structures that exhibits surface discontinuities such as edges and vertices, is of importance in a wide variety of practical applications. In this paper, a first order, high-frequency solution for the scattering by a corner is presented. The author's formulation is based on the Incremental Theory of Diffraction (ITD), which has been recently developed.

A double line integral representation of the mutual coupling between open-ended waveguides of arbitrary cross section is presented, which is useful to speed up calculations inside the framework of a Galerkin method of moments.