Accession Number : ADD008426

Title :   Two Dimensional Imaging Using Surface Wave Acoustic Devices.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Jelks,Edward C

Report Date : 06 Jan 1981

Pagination or Media Count : 10

Abstract : An apparatus is provided for processing the outputs of a two dimensional planar array of spaced apart receiving elements. The receiving elements are grouped and spaced apart in rows, which may be horizontal and vertical however, the rows may be in other directions provided they lie within a plane. The apparatus includes a plurality of surface acoustic wave (SAW) devices, each SAW device corresponding to a respective horizontal row of receiving elements and being capable of producing a plurality of horizontal phase shift outputs which linearly correspond to the number and horizontal spacing of receiving elements in a respective horizontal row. An additional SAW device is connected to the horizontal SAW devices for introducing a vertical phase shift factor in the horizontal outputs of each horizontal SAW device so that each SAW device is capable of producing a plurality of combined phase shift outputs, the vertical phase shift factor corresponding linearly to the spacing of the receiving elements in a vertical direction. The apparatus further includes a mixer which corresponds to each horizontal SAW device for mixing the combined phase shift outputs with the respective outputs of the receiving elements in a respective horizontal row so as to produce a plurality of mixed output signals. If desired, the mixed output signals may be summed, processed by an upper sideband filter, and then fed to a video device. With proper controls of the horizontal and vertical scans of the video device two-dimensional imaging can be accomplished for indicating the direction and amplitude distribution of a radiating source with respect to the planar array of listening elements.

Descriptors :   *Patents, Image processing, Acoustic signals, Arrays, Planar structures, Surface waves, Acoustic waves, Mixers(Electronics), Phase shift, Beam forming

Subject Categories : Line, Surface and Bulk Acoustic Wave Devices
      Printing and Graphic Arts

Distribution Statement : APPROVED FOR PUBLIC RELEASE