Acoustic wave transducer device
AssigneeNortel Networks Limited
InventorAndre John Van Schyndel
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Abstract
An acoustic wave transceiver device comprising a sheet of material which responds electrically to acoustic waves and a signal processor which processes the voltage signal produced by the sheet is disclosed. The sheet has an irregular shape which depends on a width function. The sheet produces a voltage signal representing the convolution of the acoustic signal information in a received wave and the width function. The signal processor deconvolves the voltage signal using said width function which is stored in its memory. A method of selecting the width function (and therefor the shape) based on the Fourier transform of a mathematical relation with orthogonal properties is also disclosed.
Claims32
An acoustic wave transducer device comprising a sheet of material which produces a voltage signal dependent on the shape of the sheet and on the pressure applied to the sheet by acoustic waves traveling in a medium external to, but in contact with, said sheet, wherein said sheet is of an irregular shape;
- wherein said irregular shape encodes spatial information into the voltage signal as said acoustic waves travel across the sheet;
- and
- wherein said voltage signal includes signal information about said acoustic wave and noise, and wherein said irregular shape is selected to encode said spatial information such that a signal processor which receives said voltage signal can preferentially extract said signal information over the noise from the voltage signal.
An acoustic wave transducer device comprising a sheet of material which produces a voltage signal dependent on the shape of the sheet and on the pressure applied to the sheet by acoustic waves traveling in a medium external to, but in contact with, said sheet, wherein said sheet is of an irregular shape wherein the material has properties which are at least approximately described by the equation:
- V ( t ) = S 0 ∫ ∫ S p ( r ⇀ , t ) ⅆ S ( 1 )
- wherein {right arrow over (r)} represents a generalized spatial position vector and S0 is the intrinsic sensitivity of the material in Volts Pa m 2 .
An acoustic wave transducer device comprising a sheet of material which produces a voltage signal dependent on the shape of the sheet and on the pressure applied to the sheet by acoustic waves traveling in a medium external to, but in contact with, said sheet, wherein said sheet is of an irregular shape wherein said shape depends on a transform of a mathematical relation with orthogonal properties.
An acoustic wave transducer device comprising a sheet of material which produces a voltage signal dependent on the shape of the sheet and on the pressure applied to the sheet by acoustic waves traveling in a medium external to, but in contact with, said sheet, wherein said sheet is of an irregular shape;
- wherein the voltage signal produced by said sheet depends on the convolution of acoustic signal information with a width function dependent on said irregular shape, wherein said acoustic signal information is a time dependent function carried by said acoustic waves;
- wherein said width function dependent on said irregular shape is selected to correspond to a known function for which the convolution of said known function and said acoustic signal is desired.
An acoustic wave transducer device comprising:
- a material which produces a voltage signal dependent on the shape of the material and on the pressure applied to the material by an acoustic wave traveling in an external medium, wherein said material is of a predetermined shape;
- and
- a signal processor for producing an output signal indicative of the pressure applied to the material as said acoustic waves travel across the material by processing said voltage signal using said predetermined shape;
- wherein said signal processor includes a memory for storing shape function data dependent on said predetermined shape.
A method of receiving acoustic signal information carried by an acoustic wave traveling in a medium comprising the steps of:
- subjecting an acoustic wave transducer material having a predetermined shape to said acoustic wave such that said material will produce a voltage signal which depends on both said shape and the characteristics of said wave as said acoustic waves travel across the sheet;
- processing said output signal to produce a desired signal which varies with the characteristics of said wave by using said predetermined shape;
- wherein the voltage signal depends on the convolution of the acoustic signal information with a width function dependent on said predetermined shape and wherein said processing step comprises deconvovling said voltage signal with said width function.
Dependencies are inferred from the claim text.