Efficient Radiation from an Electrically Small Antenna

Abstract

Applying the analytic technique, two antenna designs were found for which the radiation Q was below the limit determined by Chu for electrically small antennas. The simplest design is a turnstile antenna comprised of two perpendicularly oriented collocated electric dipoles that are phased to support circular polarization, for which the radiation Q is slightly less than a single electric dipole. The most intriguing antenna design consists of four spatially collocated equal power dipoles, a magnetic and electric dipole moment pair oriented along the x-axis, with the dipole pairs driven /2 out of phase to support circular polarization. For this source the analytically predicted radiation Q is zero independently of the relative electrical size ka of the antenna, where a is the radius of the smallest virtual sphere that circumscribes the antenna and k is the wave-number of radiation.

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Document Details

Document Type
Technical Report
Publication Date
Jun 30, 2000
Accession Number
ADA382862

Entities

People

  • Craig A. Grimes

Organizations

  • University of Kentucky

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Antennas
  • Circular Polarization
  • Conical Antennas
  • Dipole Moments
  • Electrical Engineering
  • Electrically Small Antennas
  • Electromagnetic Compatibility
  • Engineering
  • Frequency
  • Frequency Domain
  • Microwaves
  • Monopole Antennas
  • Near Field
  • Polarization
  • Radiation
  • Time Domain

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering