Accession Number : ADA112780

Title :   A Uniform GTD Solution for the Radiation from Sources on a Convex Surface.

Descriptive Note : Technical rept.,

Corporate Author : OHIO STATE UNIV COLUMBUS ELECTROSCIENCE LAB

Personal Author(s) : Pathak,P. H. ; Wang,N. N. ; Burnside,W. D. ; Kouyoumjian,R. G.

Report Date : FEB 1980

Pagination or Media Count : 47

Abstract : A compact, approximate asymptotic solution is developed for the fields radiated by antennas on a perfectly-conducting smooth convex surface. This high-frequency solution employs the ray coordinates of the Geometrical Theory of Diffraction (GTD). In the shadow region, the field radiated by the source propagates along Keller's surface diffracted ray path; whereas in the lit region, the incident field propagates along the geometrical optics ray path direct from the source to the field point. These ray fields are expressed in terms of Fock functions, which reduce to the geometrical optics field in the deep lit region and remain uniformly valid across the shadow boundary transition region into the deep shadow region. Surface ray torsion, which affects the radiated field in both the shadow and transition regions, appears explicitly in the solution as a torsion factor. The radiation patterns of slots and monopoles on cylinders, cones and spheroids calculated from this solution agree very well with measured patterns and with patterns calculated fom exact solutions.

Descriptors :   *Antenna radiation patterns, *Diffraction analysis, *Convex bodies, Solutions(General), Asymptotic series, High frequency, Coordinates, Shadows, Torsion, Monopole antennas, Antenna apertures, Optics, Paths, Electromagnetic fields, Surfaces

Subject Categories : Electricity and Magnetism
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE