The Angular Spread of the Deflected Acoustic Beam Diffracted by a Bragg Grating Out of a Surface Acoustic Wave.

Abstract

In this paper, basing on the equations of the deflection angle and of the deflection efficiency, the relation between the angular spread of the deflected SAW beam on the Bragg grating denoted by Delta-Theta sub 1 and the parameters of the grating is analyzed. A parameter referred to as "Bragg width of the angular spectrum" of the acoustic grating is defined and it is designated with Delta-Theta sub B. The meaning of the parameter Delta-Theta sub B for distinguishing the angular spread range of the deflection beam is discussed as well. It is concluded from the analysis that if the spread angle of the incident beam (labelled with Delta-Theta sub 1me) is larger than the "Bragg width of the angular spectrum: of the grating, the spread angle of the deflection beam Delta-Theta sub 1 will equal to Delta-Theta sub m; On the contrary, if the angular divergency of the incident beam is less than Delta-Theta sub B, then, Delta-Theta sub 1 = Delta-Theta sub 1me. (MM)

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Document Details

Document Type
Technical Report
Publication Date
Jan 03, 1995
Accession Number
ADA291018

Entities

People

  • Chenghao Wang
  • Zuoqing Wang

Organizations

  • National Air and Space Intelligence Center

Tags

DTIC Thesaurus Topics

  • Acoustic Beams
  • Acoustic Frequencies
  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Air Intelligence
  • Bragg Angle
  • Bragg Gratings
  • Diffraction
  • Frequency
  • Frequency Bands
  • Measurement
  • Phase Modulation
  • Spectra
  • Surface Acoustic Wave Devices
  • Surface Acoustic Waves
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Mathematical Modeling and Probability Theory.
  • Optical Physics and Photonics.