Research And Design Of Transparent Directional Acoustic Transducer

As a new type of ultrasonic transducer,the transparent directional acoustic transducer has the characteristics of good sound quality,high directivity and wide application prospect,especially in the field of electronic applications,the transparent directional acoustic transducer can be combined with the screen to transmit the ultrasonic signal that has been tuned to the medium.The nonlinear effect of ultrasonic wave in the medium makes the hyper-acoustic signal self-demodulation and produce audible signal,which can spread to a long distance and has good directivity.This transducer has greater advantages than the traditional audio directional transducer..However,the research based on transparent directional acoustic transducer is in its infancy,the related practical transparent functional materials are sparse,and the processing technology of transparent transducer is not mature,and the transparent directional acoustic transducer still has the difficulty of realizing technology.Therefore,on the basis of the existing transparent materials and processing technology,this thesis designs a new type of transparent directional acoustic transducer structure,and through simulation and experiment,carries out the research of transparent transducer based on the field of acoustic directional application.The specific research work of this topic mainly includes,based on the basic theory of acoustic orientation,the thesis studies the sound principle of transparent directional acoustic transducer,the influence of natural frequency on the critical distance of near and far field,and the influence of ultrasonic carrier frequency on the distribution of sound field.Then by s?mming up and s?mmarizing the structure of the product transducer,this thesis puts forward the technical requirements of the transparent directional acoustic transducer,and designs an effective structure of the transparent directional acoustic transducer--the structure of the circular multilayer suspension transparent transducer with piezoelectric double clamp type.Using the finite element simulation software ANSYS and the multi-physics simulation software COMSOL Multiphysics to carry on the vibration analysis and the Sound field simulation analysis to the different sizes of the transducer,the different thickness of each layer and the different materials of the elastic layer.Through simulation,the size of the first order resonant frequency and the pressure level decreases with the increase of the radius of the array,and increases with the increase of the thickness of the elastic layer or the insulating layer.The transducer samples of the simulation results is in accordance with the design research target are processed and manufactured.Finally,the experimental test platform is built,and the frequency response curve and directivity of the transducer are obtained after testing.Simulation and experimental results show that the designed transparent directional acoustic transducer has good directivity,and the pointing angle of the main lobe beam is between the ±30°,and the size of the first-order resonant frequency and the pressure level obtained by the experimental test are consistent in the error range with the results obtained by theoretical calculation and simulation.The operating frequency of the transducer is within the ultrasonic range(30kHz~70kHz),and the acoustic pressure level can reach more than 70 dB,which verifies that the designed transparent directional acoustic transducer has certain feasibility.