Accession Number : ADA138049

Title :   Pattern Nulling by Reflector Shaping.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Havens,D A

PDF Url : ADA138049

Report Date : Dec 1983

Pagination or Media Count : 110

Abstract : The applicability of adaptive array concepts to continuous aperture antennas was studied and appropriate aperture field distributions for pattern nulling were found from them. The adaptive array weights were found to be useful as discrete points in a continuous distribution. This distribution could then be used in an aperature integration scheme to produce a nulled pattern. Also studied was the use of geometrical optics to calculate the aperture field distribution of an arbitrarily shaped reflector. Under some restrictions, geometrical optics can provide a useful approximation. Constructing the aperture field of a reflector defined by a discrete grid of points using a numerical ray tracing scheme was also investigated. Certain numerical problems were identified. Finally, an attempt was made to implement the nulled pattern by a well known beamshaping method based on geometrical optics principles. This technique was found to be inadequate. More promising techniques for implementing the aperture distributions were suggested but not pursued in this work. (Author)

Descriptors :   *Antenna radiation patterns, *Reflectors, *Nulls(Amplitude), *Adaptive systems, *Antenna arrays, Computer programs, Antenna apertures, Discrete distribution, Ray tracing, Grids(Coordinates), Numerical analysis, Integration, Optics, Distribution, Shape, Geometry, Weight, FORTRAN, Subroutines, Arrays, Theses

Subject Categories : Electrical and Electronic Equipment
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE