Acoustical source and transducer having, and method for, optimally matched acoustical impedance
OwnerJoie P. Jonesinventor
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Abstract
The invention, in its several embodiments, includes a method of making a plurality of impedance-matched layers interposes between an acoustical source and a target media providing optimal transmission of energy from the acoustical source to the target media.
Claims8
A method of making a transducer having a plurality of impedance matched layers comprising:
- providing a piezoelectric element having a source impedance, Z0;
- selecting a target medium having a target impedance, Z(N+1);
- defining a number of matching layers, N, wherein N is an integer greater than unity;
- and
- for each matching layer, J, incremented 1 to the defined number of matching layer, N:
- determining a required impedance according to:
- ZJ=Z0[(N+1−J)/(N+1)]Z(N+1)(J/N+1);
- selecting a material for matching layer J having substantially the determined required impedance ZJ wherein the selected material for matching layer J has a speed of sound and a wavelength λJ associated with the speed of sound for matching layer J;
- determining a positive integer value, NJ, and a thickness, LJ, of the selected material for matching layer J according to:
- LJ=(2nJ−1)λJ/4;
- and
- applying the matching layer J of thickness LJ to the transducer.
A method of making a transducer having a plurality of impedance matched layers comprising:
- providing an acoustical source having a derived effective source impedance, ZEFF;
- selecting a target medium having a target impedance, Z(N+1);
- defining a number of matching layers, N, wherein N is an integer great than unity;
- and
- for each matching layer, J, incremented 1 to the defined number of matching layer, N:
- determining a required impedance according to:
- ZJ=ZEFF[(N+1−J)/(N+1)]Z(N+1)(J/N+1);
- selecting a material for matching layer J having substantially the determined required impedance ZJ wherein the selected material for matching layer J has a speed of sound and a wavelength λJ associated with the speed of sound for matching layer J;
- determining a positive integer value, nJ, and a thickness, LJ, of the selected material for matching layer J according to:
- LJ=(2nJ−1)λJ/4;
- and
- applying the matching layer J of thickness LJ to the transducer.
An apparatus for transmitting acoustical energy to a target medium having a target impedance, the apparatus comprising:
- a piezoelectric element having a source impedance, Z0, and a plurality of matching layers;
- wherein each of the plurality of matching layers, has a required impedance according to:
- ZJ=Z0[(N+1−J)/(N+1)]Z(N+1)(J/N+1);
- and a wavelength λJ and
- wherein each of the plurality of matching layers has a thickness according to:
- LJ=(2nJ−1)λJ/4,
- wherein nJ is a positive integer;
- and
- wherein the plurality of matching layers is bonded to the piezoelectric element.
An article for matching acoustical energy from a source having an impedance, Z0[(N+1−J)/(N+1)], to a target medium having a target impedance, Z(N+1)(J/N+1), the article comprising:
- a plurality of matching layers, N, wherein each of the plurality of matching layers, J, has a required impedance, ZJ, according to:
- ZJ=Z0[(N+1−J)/(N+1)]Z(N+1)(J/N+1);
- and a wavelength λJ.
Dependencies are inferred from the claim text.