Leaky and surface wave diffraction by an asymmetric impedance half plane

1983 ◽  
Vol 61 (6) ◽  
pp. 906-918
Author(s):  
W. Nasalski

An exact solution is obtained for the problem of a leaky or surface wave incident on an impedance half plane in a homogeneous, isotropic medium. The impedance half plane is asymmetric, i.e., with different constant surface impedances at the upper and lower faces, respectively. The incident leaky wave propagates in a direction normal to the edge of the half plane.The diffraction problem leads to a set of two coupled Wiener–Hopf equations, from which two Hilbert problems on a new contour are obtained and solved. The Wiener–Hopf–Hilbert method is used. Expressions for the geometrical optical field are also derived and results arc discussed from the point of view of the uniqueness of the solution.

The two-dimensional wave diffraction problem, acoustic or electromagnetic, in which a pulse of step-function time dependence is diffracted by a resistive half-plane is solved by assuming dynamic similarity in the solution.


1967 ◽  
Vol 34 (1) ◽  
pp. 100-103 ◽  
Author(s):  
A. Jahanshahi

The exact solution to the problem of diffraction of plane harmonic polarized shear waves by a half-plane crack extending under antiplane strain is constructed. The solution is employed to study the nature of the stress field associated with an extending crack in an elastic medium excited by stress waves.


2016 ◽  
Vol 14 (38) ◽  
pp. 9-28
Author(s):  
Hernan G. Triana ◽  
Andrés Navarro Cadavid

AbstractThe Sommerfeld exact solution for canonical 2D wedge diffraction problem with perfectly conducting surfaces is presented. From the integral formulation of the problem, the Malyuzhinets solution is obtained and this result is extended to obtain the general impedance solution of canonical 2D wedge problem. Keller’s asymptotic solution is developed and the general formulation of exact solution it’s used to obtain general asymptotic methods for approximate solutions useful from the computational point of view. A simulation tool is used to compare numerical calculations of exact and asymptotic solutions. The numerical simulation of exact solution is compared to numerical simulation of an asymptoticmethod, and a satisfactory agreement found.  Accuracy dependence with frequency is verified.


1974 ◽  
Vol 26 (3) ◽  
pp. 531-538 ◽  
Author(s):  
Richard C. Morgan ◽  
Samuel N. Karp

Author(s):  
Gennady Devyatkov ◽  

When solving problems of broadband matching, very often there is a need for a certain form of the amplitude-frequency characteristic. In connection with this, the problem comes up of synthesizing broadband matching devices that simultaneously have correcting properties, i.e. having a given frequency dependence of the power conversion coefficient in the operating frequency band. The use of broadband reactive matching - correcting circuits in most practical cases is difficult because of the reflected power. This leads to the problem of the synthesis of broadband matching-correcting circuits with arbitrary immittances of the signal source and load in an elemental basis of a general form, containing along with reactive and active elements, which has not been adequately solved. Therefore, it becomes necessary to find the conditions for the physical realizability of a typical component of the immitance matrix of a two-port network of general form containing poles in the left half-plane of complex frequencies. In this paper the necessary and sufficient conditions are defined for the physical realizability of the immitance matrix of a typical component of a subclass of two-terminal networks of general form in a lumped elemental electric basis, when the poles of the Eigen functions in the Foster representation can be in the left half-plane of complex frequencies, excluding the imaginary and real axes. This allows to synthesis of broadband dissipative matching, matching-correcting circuits and matched attenuators in an elemental basis of a general form with arbitrary immitances of the signal source and load from a single point of view.


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