Sound generator for use in parametric array
A sound generator includes a transducer converting electric energy to mechanical energy, a mechanical amplifier mechanically amplifying a vibration generated in a piezoelectric component of the transducer, and a radiation plate radiating a sound wave from a signal amplified by the mechanical amplifier, wherein the radiation plate includes a first step having a height for compensating for a first resonance frequency and a second step having a height for compensating for a second resonance frequency.
1. A sound generator comprising:
a transducer configured for converting electric energy to mechanical energy;
a mechanical amplifier configured for mechanically amplifying a vibration generated in a piezoelectric component of the transducer; and
a radiation plate configured for radiating a sound wave from a signal amplified by the mechanical amplifier,
wherein the radiation plate includes a first step and a second step, the first step having a first height, the first height being an odd multiple of a half of an in-air wavelength of the sound wave at a first resonance frequency of the radiation plate, the second step having a second height, the second height being an odd multiple of a half of an in-air wavelength of the sound wave at a second resonance frequency of the radiation plate and an integer multiple of the wavelength of the sound wave at the first resonance frequency.
2. The sound generator according to claim 1 , wherein the first height is (n/2 m)λ and the second height (y/2)λ satisfies (y/2)λ=x(n/m)λ for an integer x and an odd integer y, where m represents the first resonance frequency, n represents the second resonance frequency, and λ represents an in-air wavelength of the second resonance frequency.
3. The sound generator according to claim 1 , wherein the transducer is a Langevin type transducer of which a piezoelectric component is fastened with a bolt.
4. The sound generator according to claim 1 , wherein the mechanical amplifier has at least one structure of a stepped horn, a linear horn, and an exponential horn.
5. The sound generator according to claim 1 , wherein the radiation plate is formed of an elastic material.
6. The sound generator according to claim 1 , wherein the radiation plate is divided into a first area including a plurality of first steps and a second area including a plurality of the second steps.
7. The sound generator according to claim 1 , wherein the radiation plate is used for generating a parametric array mechanism.
8. A radiation plate for radiating a sound wave, comprising:
a plate;
a first step formed on the plate; and
a second step formed on the plate,
wherein the first step has a first height, the second step has a second height, the first height is an odd multiple of a half of an in-air wavelength of the sound wave at a first resonance frequency of the radiation plate, and the second height is an odd multiple of a half of a wavelength of the sound wave at a second resonance frequency of the radiation plate and an integer multiple of the wavelength of the sound wave at the first resonance frequency.
9. The radiation plate according to claim 8 , wherein the first height is (n/2 m)λ and the second height (y/2)λ satisfies (y/2)λ=x(n/m)λ for an integer x and an odd integer y, where m represents the first resonance frequency, n represents the second resonance frequency, and λ represents an in-air wavelength of the second resonance frequency.
10. The radiation plate according to claim 8 , wherein the plate, the first step and the second step are formed of an elastic material.
11. The radiation plate according to claim 8 , wherein the plate is divided into a first area and a second area, and wherein a plurality of first steps are formed on the first area and a plurality of second steps are formed on the second area.