UNIFORM EVALUATION OF RADIATION FIELDS.

Abstract

Solutions to many problems involving electromagnetic wave propagation are often given as contour integrals in the wave number plane which unfortunately cannot be readily evaluated. By employing the method of steepest descents, asymptotic expansions can be found to determine the far fields, but these furnish little information on the transition region from the source to the Fraunhofer region. In this work, a procedure is introduced which facilitates the evaluation of Fourier-type integrals in the Fresnel zone. The present method decomposes the integral representation into a standard form: a linear combination of two Hankel functions of the first kind, trigonometric functions. With this result, an exact representation which is uniformly valid from the near zone to the far field is obtained. The useful domain also includes such regions as the critical angles in real space, corresponding to the shadow boundaries associated with the pole contributions.

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1965
Accession Number
AD0622407

Entities

People

  • John P. Cretella
  • Julius Kane

Organizations

  • University of Rhode Island

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Asymptotic Series
  • Boundaries
  • Contour Integrals
  • Electromagnetic Wave Propagation
  • Far Field
  • Fresnel Zones
  • Integrals
  • Mathematics
  • Radiation
  • Standards
  • Test And Evaluation
  • Transitions
  • Wave Phenomena
  • Wave Propagation

Readers

  • Calculus or Mathematical Analysis
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering

Technology Areas

  • Space