Accession Number : AD0681125

Title :   ELECTROMAGNETIC SCATTERING FROM CERTAIN RADIALLY INHOMOGENEOUS DIELECTRICS.

Descriptive Note : Doctoral thesis,

Corporate Author : MICHIGAN UNIV ANN ARBOR RADIATION LAB

Personal Author(s) : Alexopoulos,Nicolaos Georgiou

Report Date : NOV 1968

Pagination or Media Count : 109

Abstract : The phenomenon of electromagnetic wave propagation through, and scattering from, radially inhomogeneous dielectrics is studied for very high frequencies. The dielectrics are considered lossless, radially inhomogeneous in the spherical coordinates system, and of the converging or of the diverging type. The lens problem is studied by the geometrical optics technique and the radar cross-section of perfectly conducting spheres coated with radially inhomogeneous dielectrics is investigated. By assuming a plane wave as the incident electromagnetic field, the contribution in the backscattering direction due to the reflected field and the creeping waves is determined by applying asymptotic theory. This necessitates the use of the WKB and/or Langer's method for the solution of the pertinent differential equations, depending on whether there exist transition points in the range for which the solutions are required. Also, the integrals of Scott are needed in order to determine the reflected portion of the field. Such a study is interesting not only from the theoretical but also from the practical point of view, in that it lends itself useful to the understanding of radio wave propagation in radially inhomogeneous dielectrics and of the effect of coating perfectly conducting spheres with radially inhomogeneous media. It also has applications to problems of wave propagation in the ionosphere and around the earth. (Author)

Descriptors :   (*ELECTROMAGNETIC RADIATION, SCATTERING), VERY HIGH FREQUENCY, DIELECTRICS, SPHERES, RADIOFREQUENCY LENSES, RADAR CROSS SECTIONS, ELECTROMAGNETIC WAVE REFLECTIONS, BOUNDARY VALUE PROBLEMS, IONOSPHERIC PROPAGATION, THESES

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE