Various acoustic waves from the electronic devices, such as PCs, game consoles, and private portable multimedia players, in a closed space are often regarded as noises to the adjacent people and may, sometimes, lead them to the confusion of information. Under those circumstances, it is necessary to ...
Various acoustic waves from the electronic devices, such as PCs, game consoles, and private portable multimedia players, in a closed space are often regarded as noises to the adjacent people and may, sometimes, lead them to the confusion of information. Under those circumstances, it is necessary to reduce the noises and transmit the acoustic information effectively to the concerned people without any confusion. In order to deliver the acoustic informations effectively to the desired direction, this paper focuses on the directivity of acoustic wave from the linear array of piezoelectric speakers, which is based on the directivity of electromagnetic wave from the linear array of several antennas. To realize the directional acoustic wave, various experiments were carried out in an anechoic chamber set up with specified measuring equipments and systems. For the experiments, signal generator and phase controller were, also, designed and fabricated. 2~5 commercial piezoelectric speakers were arranged in a straight line with same intervals such as λ/4, λ/2, and 3λ/4, where λ is the wavelength of the acoustic wave. And each of the speakers was supplied with an electric signal of same frequency and phase difference. Then the acoustic wave, generated from the linear array of the piezoelectric speakers, may either weaken by canceling out or strengthen by reinforcing in a specific direction. 2- and 3-dimensional simulation techniques were introduced to compare the experimental results with the theoretical results as well. Through those experiments and simulations, following results could be obtained for the desired directional transmission of the acoustic wave. The stronger and narrower beam patterns of the acoustic wave could be obtained by increasing the number of sound sources from 2 to 5 under the conditions of same input frequency, phase difference, and interval. These phenomina mean that more numbers of sound source composing the linear array are necessary for the transmission of the narrower acoustic beam to a confined area. The directivity of acoustic beam patterns could be regulated by adjusting the phase differences of electrical inputs between the adjacent sound sources. When the phase differences between the adjacent sound sources were 0^(0) , main lobes surrounded the center of the linear array. However, when the phase differences were increased, main lobes gathered gradually in one direction. These facts mean that the direction of acoustic wave can be regulated by adjusting the electric phase differences between the adjacent sound sources. In order to get a desired direction of acoustic wave by adjusting the phase differences under the condition of fixed number of sound sources, fixed spacings, and specified frequency, theoretical expressions and graphic solutions were introduced. And the experimental results agreed well with the theoretical results below the error of 3.0% for typical cases.
Various acoustic waves from the electronic devices, such as PCs, game consoles, and private portable multimedia players, in a closed space are often regarded as noises to the adjacent people and may, sometimes, lead them to the confusion of information. Under those circumstances, it is necessary to reduce the noises and transmit the acoustic information effectively to the concerned people without any confusion. In order to deliver the acoustic informations effectively to the desired direction, this paper focuses on the directivity of acoustic wave from the linear array of piezoelectric speakers, which is based on the directivity of electromagnetic wave from the linear array of several antennas. To realize the directional acoustic wave, various experiments were carried out in an anechoic chamber set up with specified measuring equipments and systems. For the experiments, signal generator and phase controller were, also, designed and fabricated. 2~5 commercial piezoelectric speakers were arranged in a straight line with same intervals such as λ/4, λ/2, and 3λ/4, where λ is the wavelength of the acoustic wave. And each of the speakers was supplied with an electric signal of same frequency and phase difference. Then the acoustic wave, generated from the linear array of the piezoelectric speakers, may either weaken by canceling out or strengthen by reinforcing in a specific direction. 2- and 3-dimensional simulation techniques were introduced to compare the experimental results with the theoretical results as well. Through those experiments and simulations, following results could be obtained for the desired directional transmission of the acoustic wave. The stronger and narrower beam patterns of the acoustic wave could be obtained by increasing the number of sound sources from 2 to 5 under the conditions of same input frequency, phase difference, and interval. These phenomina mean that more numbers of sound source composing the linear array are necessary for the transmission of the narrower acoustic beam to a confined area. The directivity of acoustic beam patterns could be regulated by adjusting the phase differences of electrical inputs between the adjacent sound sources. When the phase differences between the adjacent sound sources were 0^(0) , main lobes surrounded the center of the linear array. However, when the phase differences were increased, main lobes gathered gradually in one direction. These facts mean that the direction of acoustic wave can be regulated by adjusting the electric phase differences between the adjacent sound sources. In order to get a desired direction of acoustic wave by adjusting the phase differences under the condition of fixed number of sound sources, fixed spacings, and specified frequency, theoretical expressions and graphic solutions were introduced. And the experimental results agreed well with the theoretical results below the error of 3.0% for typical cases.
주제어
#Piezoelectric Acoustic Linear
※ AI-Helper는 부적절한 답변을 할 수 있습니다.