Accession Number : AD0439210


Title :   TRANSIENT SOLUTIONS FOR A CLASS OF DIFFRACTION PROBLEMS,


Corporate Author : POLYTECHNIC INST OF BROOKLYN N Y MICROWAVE RESEARCH INST


Personal Author(s) : FELSEN,L B


Report Date : 06 Mar 1964


Pagination or Media Count : 28


Abstract : The study of the fields excited by impulsive sources in layered media has been facilitated by a technique employed originally be Cagniard and Pekeris, and simplified subsequently be de Hoop. The procedure involves a reformulation of the time-harmonic solution so as to permit the explicit recovery of the transient result by inspection. In the present note, it is shown that this method may be applied conveniently to the inversion of a certain Sommerfeld-type integral which occurs frequently in diffraction theory, thereby unifying the analysis of a class of pulse diffraction problems. Illustrative examples include the transient response to a line source in the presence of a dielectric half space, a perfectly absorbing and perfectly reflecting wedge, and a unidirectionally conducting infinite and semi-infinite screen. The latter applications illuminate the role of surface waves in the impulsive solution. It is found, in contrast to the time-harmonic case, that a different behavior characterizes the surface waves excited on a undirectionally conducting half plane by the incident field and by the edge discontinuity, respectively. (Author)


Descriptors :   *DIFFRACTION , *HARMONIC ANALYSIS , SCATTERING , TRANSFORMATIONS(MATHEMATICS) , INTEGRALS , DIELECTRICS , EXCITATION , ELECTRIC FIELDS


Distribution Statement : APPROVED FOR PUBLIC RELEASE