Broadband Parametric Array Synthesis System Design And Implementation Of The Beam

broadband beamforming system based on the parametric acoustic array is theproduct of the combination of parametric array technology and phased array technology.Recently, parametric acoustic array as a research focus in acoustic field is an importanttechnology. The audio directional system which is developed by authors’ team is thefirst sound source that can generate an audible sound with high directivity. Phased arraytechnology which owns more than20years history of development has extensiveapplication in many fields. It can improve system efficiency effectively, while reduceenergy loss.This paper provides the study of low-frequency acoustic directional principle basedon the parametric acoustic array. According to the extension of the acoustic directionalsystem, the broadband beamforming system can control the directivity of the audiblesound with high directivity by E-deflection mode. The basic principle of thebeamforming system is explained according to the parametric acoustic array theory.This paper has a brief description of Westervelt formula, Berktay far field solution andKZK formula. The transducer array can provide the required three-dimensionaldirectivity by an appropriate combination because of the directivity of transducer. Whilephased array beamforming theory explains phased array technology is very important tobeforming system. This paper designs a cylindrical transducer array by the linear arrayas one unit. The smallest unit is cutting prezoelectric transducer named Tonpilz. Thesuitable phase control algorithm is proposed according to the modus of transducer andthe self-demodulation formula. Through analysis of system performance, this paperproposes a combination of two delay control methods can improve the accuracy of thesystem. The signal processing platform of beamforming system is designed based onFPGA. According to the research of input, the rational interface and waveform storagesolutions are found. While the Deflection algorithm and the launch time control for eachchannel are realized on this platform. The function of the system’s each module isverifies by function simulation, timing simulation and logic simulation in ISE.The aforementioned theory and key technologies employed, a prototype used has been developed successfully. Important technologies involved are from the research ofunderwater broadband beamforming system based on the parametric acoustic array. Bythe test result, the system with beamforming function can not only produce an audiblesound with high directivity but also controllable directivity in water.