A Near to Far Transformation using Spherical Expansions Phase 1: Verification on Simulated Antennas

Abstract

Tapan Sarkar wrote a substantial technical paper on a transformation mapping an antennas near-field into its far field. A numerical implementation of Sarkars near-to-far transformation is assessed in this report. This report assesses this near-to-far implementation on the following antenna models using only a finite number of near-field samples: Analytic antenna models where the near field, far field, and the spherical expansions are computable in closed form, Mini-NEC antenna simulations where the near field, far fields and spherical expansions are numerically computed. The implementation described in this report demonstrates that an antennas far field can be extracted from sampled near field measurements provided the spherical expansion includes a sufficient number of terms and that the near-field samples are sufficiently dense. Phase II of this effort extends the implementation to estimate the number of spherical coefficients necessary to deliver user-specified accuracy in the far field and how noisy the near-field measurements affect the far field approximation.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2014
Accession Number
AD1023767

Entities

People

  • J. C. Allen
  • John H. Meloling

Organizations

  • Naval Information Warfare Systems Command

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Bessel Functions
  • Communication Systems
  • Computations
  • Department Of Defense
  • Direction Finding
  • Electric Fields
  • Far Field
  • Governments
  • Loop Antennas
  • Near Field
  • Numerical Quadrature
  • Radiation
  • Simulations
  • Three Dimensional
  • Two Dimensional
  • United States Government

Readers

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