THEORETICAL AND EXPERIMENTAL INVESTIGATION OF FOCAL PLANE ADAPTIVE ANTENNA TECHNIQUES

Abstract

A scalar analysis was performed to determine the field structure in the focal region of apertures focused in their near field (f/D<1). Solutions are given for plane waves at normal incidence, and several selected angles of arrival. The results indicate a substantial variation from the Fraunhofer far field patterns. Because it is a scalar approach, it is limited to large apertures (D>> wavelength) and small diffraction angles. An experiment was designed to complement the analysis. The qualitative agreement is very good. Sources of experimental error have been found which account for the quantitative variations. A technique for determining the field structure in the focal region, due to a reasonably arbitrary distribution in the aperture plane, is given. It consists of the superposition of an ensemble of plane waves, whose amplitude, relative phase, and angle of arrival are determined by the aperture plane distribution.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1968
Accession Number
AD0670830

Entities

People

  • Marvin Cohn
  • Robert S. Littlepage

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Agreements
  • Air Force
  • Amplitude
  • Angle Of Arrival
  • Diffraction
  • Equations
  • Far Field
  • Focal Planes
  • Geometry
  • Near Field
  • Physics Laboratories
  • Plane Waves
  • Radiation
  • Three Dimensional
  • Two Dimensional
  • Waves

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Phased Array Antenna Design.