Beaming sound waves using phononic crystals

Patent metadata

Field	Value
Publication number	US-12027150-B2
Application number	US-202217864131-A
Country	US
Kind code	B2
Filing date	Jul 13, 2022
Priority date	Jul 13, 2022
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

A method for beaming sound waves includes introducing sound waves into a phononic crystal in a first direction. The phononic crystal has an array of C-shaped structures oriented so that a neck of each of the C-shaped structures is facing the same general direction. The sound waves are beamed in the direction in which the neck of each of the C-shaped structures is facing so that the sound waves are beamed from the phononic crystal in a second direction that is different from the first direction.

First claim

What is claimed is:

1. A method for beaming sound waves comprising:
introducing sound waves into a phononic crystal in a first direction, the phononic crystal comprising an array of C-shaped structures oriented so that a neck of each of the C-shaped structures is facing the same general direction, wherein
an outer radius of the C-shaped structures satisfies the following equation:
kr o ≈1

wherein k is the wave number and r o is the outer radius of the C-shaped structure; and
a distance between adjacent C-shaped structures satisfies the following equation:
nλ= 2 d sin θ

wherein n is the order of Bragg scattering, λ is the wavelength of sound waves to be beamed, d is the distance between adjacent C-shaped structures in the array of C-shaped structures, and θ is an angle of a neck of C-shaped structures relative to a line perpendicular to the first direction; and
beaming the sound waves in the direction in which the neck of each of the C-shaped structures is facing so that the sound waves are beamed from the phononic crystal in a second direction that is different from the first direction.

2. The method for beaming sound waves of claim 1 , wherein the second direction is from 45° to 135° relative to the first direction.

3. The method for beaming sound waves of claim 1 , wherein the second direction is from 75° to 105° relative to the first direction.

4. The method for beaming sound waves of claim 1 , wherein the second direction is approximately 90° relative to the first direction.

5. The method for beaming sound waves of claim 1 , wherein the array of C-shaped structures comprises a plurality of C-shaped structures arranged in columns and rows.

6. The method for beaming sound waves of claim 5 , wherein a distance between adjacent C-shaped structures satisfies the following equation:

f
=

c
d

wherein f is the (center) frequency of the sound waves entering the phononic crystal; c is the speed of sound in air; and d is the distance between adjacent C-shaped structures.

7. The method for beaming sound waves according to claim 1 , wherein
a transmission ratio of an intensity of the sound waves in the first direction to sound waves in the second direction is greater than 5, and
the sound waves have a frequency of greater than 5100 Hz and less than 5400 Hz.

8. The method for beaming sound waves according to claim 1 , wherein
a transmission coefficient of the sound waves in the second direction is greater than 0.4, and
the sound waves have a frequency of greater than or 5100 Hz and less than 5400 Hz.

9. A phononic crystal comprising:
an array of C-shaped structures oriented so that a neck of each of the C-shaped structures is facing the same general direction, wherein
an outer radius of the C-shaped structures satisfies the following equation:
kr o ≈1

wherein k is the wave number and r o is the outer radius of the C-shaped structure; and
a distance between adjacent C-shaped structures satisfies the following equation:
nλ= 2 d sin θ

wherein n is the order of Bragg scattering, λ is the wavelength of sound waves to be beamed, d is the distance between adjacent C-shaped structures in the array of C-shaped structures, and θ is an angle of a neck of C-shaped structures relative to a line perpendicular to the first direction; and
the C-shaped structures are configured so that the neck of each of the C-shaped structures is positioned to face a second direction that is different from a direction of sound waves incident to the phononic crystal.

10. The phononic crystal of claim 9 , wherein the second direction is from 45° to 135° relative to the direction of incident sound waves.

11. The phononic crystal of claim 9 , wherein the second direction is from 75° to 105° relative to the direction of incident sound waves.

12. The phononic crystal of claim 9 , wherein the second direction is approximately 90° relative to the direction of incident sound waves.

13. The phononic crystal of claim 9 , wherein the array of C-shaped structures comprises a plurality of C-shaped structures arranged in columns and rows.

14. The phononic crystal of claim 13 , wherein a distance between adjacent C-shaped structures satisfies the following equation:

f
=

c
d

wherein f is the (center) frequency of the sound waves entering the phononic crystal; c is the speed of sound in air; and d is the distance between adjacent C-shaped structures.

Assignees

• Toyota Eng & Mfg North America
• Toyota Motor Co Ltd

Inventors

• Su Xiaoshi
• Banerjee Debasish

Classifications

• G10K11/28 Primary

  using reflection, e.g. parabolic reflectors · CPC title

• G10K11/26 Primary

  Sound-focusing or directing, e.g. scanning · CPC title