INFINITE SHEATH HELICAL ANTENNA.

Abstract

The problem of an infinite sheath helical antenna driven by a ring delta generator is considered. The Fourier transform technique is used to solve this problem. It is found that if the radius of the helix is not too large, beta b < 2.4048, where beta = 2 pi/lambda and b is the radius of the helix, the current density far away from the driving point can be decomposed into two terms. The first term is constant in magnitude and its phase velocity is less than the speed of light. It is a slow wave term. The second term dies out as 1/z(2), where z is the axial distance from the driving point, and has a constant phase velocity of beta. This is the radiation term. Near to the driving point, the logarithmic singularity exists just as in the case of an infinite linear, perfectly conducting dipole antenna. (Author)

Document Details

Document Type
Technical Report
Publication Date
Oct 20, 1964
Accession Number
AD0612643

Entities

People

  • Chin-lin Chen

Organizations

  • Harvard University

Tags

DTIC Thesaurus Topics

  • Antennas
  • Current Density
  • Dipole Antennas
  • Dipoles
  • Generators
  • Helical Antennas
  • Phase Velocity
  • Physical Properties
  • Radiation

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Plasma Physics / Magnetohydrodynamics