REFLECTION OF ELECTROMAGNETIC WAVES FROM SOUND WAVES

Abstract

The reflection of electromagnetic waves normally incident on the wavefronts of a semi-infinite standing sound wave is discussed. By analogy with the Bragg reflection in optics, a maximum reflection occurs when the wavelength of the electromagnetic radiation in the sound perturbed region is twice the acoustic wavelength. Since the reflecting planes of maximum sound pressure disappear periodically, the reflected electromagnetic signal is modulated with the sound frequency. An experiment is described in which the Bragg reflection of 3 cm electromagnetic waves from a standing sound wave beneath a water surface is observed.

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Document Details

Document Type
Technical Report
Publication Date
Aug 10, 1959
Accession Number
AD0226886

Entities

People

  • H. J. Schmitt

Organizations

  • Harvard University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Frequencies
  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Dielectric Permittivity
  • Dielectric Properties
  • Diffraction
  • Doppler Effect
  • Electric Fields
  • Electromagnetic Radiation
  • Frequency
  • Frequency Bands
  • Microwave Frequency
  • Modulation
  • Radio Frequency
  • Sound Pressure
  • Sound Waves

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Optical Fiber Sensing and Electromagnetic Propagation.
  • Plasma Physics / Magnetohydrodynamics