×

Acoustic wave devices

  • US 4,336,514 A
  • Filed: 09/18/1980
  • Issued: 06/22/1982
  • Est. Priority Date: 09/20/1979
  • Status: Expired due to Term
First Claim
Patent Images

1. In a surface acoustic wave (SAW) device including input means for generating acoustic waves, output means for delivering a signal from the device and a frequency-selective reflective array which comprises a plurality of parallel rows of individual scatterers, each scatterer forming one or more scattering centres from which acoustic waves, generated by the input means and propagated to the array, are scattered in a desired predetermined direction by Bragg reflection, the improvement consisting essentially of and in combination with the above elements:

  • the scatterers being disposed such that the local spacing between scattering centres, in relation to the acoustic wavelength at the frequency at which Bragg reflection occurs in the desired direction, said Bragg reflection frequency being determined by the inter-row spacing associated with the row or rows containing those scattering centres, causes the acoustic waves scattered from the individual scattering centres at the Bragg reflection frequency to constructively interfere in the desired predetermined direction and to not constructively interfere in directions other than the desired direction.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×