Accession Number : AD0648717

Title :   STUDY OF THE SCATTERING BEHAVIOR OF A SPHERE WITH AN ARBITRARILY PLACED CIRCUMFERENTIAL SLOT,

Corporate Author : MICHIGAN UNIV ANN ARBOR RADIATION LAB

Personal Author(s) : Chang,Seichoong ; Senior,Thomas B. A.

Report Date : FEB 1967

Pagination or Media Count : 63

Abstract : The electromagnetic scattering behavior of a metallic sphere loaded with a circumferential slot arbitrarily placed with respect to the direction of incidence is studied. Under the assumption that the slot is of small but nonzero width with a constant electric field across it, the analysis for the external fields is exact. Expressions for the scattered far field components, as well as for the total surface field components, are derived and then used to investigate the extent to which the scattering behavior can be controlled by varying the loading admittances and the slot position. An explicit formula for the loading of the zeroth mode to annul the back scattering cross section is derived, and from this the desired loading is obtained by means of a lumped load at the center of a radial cavity backing the slot. In particular, emphasis is placed on the case where the slot is in the plane of incidence and normal to the direction of the incident electric vector. The numerical study is limited to the frequency range 0 < ka < 3.0, where a is the radius of the sphere, and results are presented primarily for back scattering. To verify some of these results, a comparison is made with experimental data obtained using a metallic sphere with an equatorial slot backed by a radial cavity of adjustable depth. (Author)

Descriptors :   (*ELECTROMAGNETIC RADIATION, SCATTERING), (*SPHERES, SCATTERING), RADAR REFLECTIONS, WAVE FUNCTIONS, SURFACES, ADMITTANCE, ELECTRICAL IMPEDANCE

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE