Accession Number : AD0678063

Title :   ELECTROMAGNETIC SCATTERING BY FINNED OBJECTS,

Corporate Author : PURDUE UNIV LAFAYETTE IND SCHOOL OF ELECTRICAL ENGINEERING

Personal Author(s) : Ruckgaber,G. M. ; Schultz,F. V.

Report Date : JUN 1968

Pagination or Media Count : 266

Abstract : Solutions are obtained for the scattering of an incident plane electro-magnetic wave by each of the following perfectly conducting objects: (a) an infinite circular cylinder having an attached sector, which, in the limiting case of zero sector angle, becomes a circular cylinder having a fin, (b) an infinite circular cylinder having two coplanar fins, which, in the limiting case of zero cylinder radius, becomes a strip, (c) a sphere having a fin, which, in the limiting case of zero sphere radius, becomes a circular disc. In each problem, the scatterer is described by sections of constant-coordinate surfaces and the space surrounding the scatterer is partitioned into several regions. The electromagnetic field in each region is expanded in a complete set of Hansen vector wave functions with unknown expansion coefficients. These sets of expansion coefficients are then determined by satisfying the boundary conditions. A review of scattering by the circular cylinder and sphere is also presented. Numerical results are obtained for scattering by the one-finned cylinder, the finned sphere, and circular disc. For the one-finned cylinder and the finned sphere, the results show the effect of the fin on the back scattering by the cylinder and the sphere, respectively. In the case of the circular disc, the results for the back-scattering radar cross section agree with the values given by the solution of W. Andrejewski and that of physical optics. (Author)

Descriptors :   (*CYLINDRICAL BODIES, *RADAR CROSS SECTIONS), FINS, SCATTERING, ELECTROMAGNETIC RADIATION, DISKS, SPHERES, BOUNDARY VALUE PROBLEMS, PARTIAL DIFFERENTIAL EQUATIONS, WAVE FUNCTIONS

Subject Categories : Active & Passive Radar Detection & Equipment
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE