A beamforming method for window function weighted electro-acoustic transducer transmit arrays

Abstract

The invention relates to a beamforming method for a window function weighted electro-acoustic transducer transmitting array. The proportional coefficients of sound pressure amplitude of each sound source in the emission array are weighted by the window function which is selected by calculation and experiment, a set of numerical values with a specific window function is obtained, and set to be thegain value of each amplifier, or the sensitivity value of each electroacoustic transducer, so that electro-acoustic transducer radiates sound pressure with different amplitudes. The signal processingsystem of the invention is simple, and the corresponding window function can be flexibly selected according to the requirement, so that the radiated sound field formed has directivity characteristic that hardly changes with the frequency in the wide band working frequency range, and has specific beam width and small sidelobe.

Description

technical field [0001] The invention relates to the technical field of electroacoustic signal conversion and emission in underwater acoustic electronic communication, in particular to a window function weighted broadband constant beam width electroacoustic transducer emission array. Background technique [0002] In the fields of sound reinforcement design, broadband underwater acoustic emission array design, and broadband underwater acoustic communication, it is often necessary to radiate a sound field with specific directivity characteristics, and the radiated sound field is required to have strong consistency within a wide frequency range to avoid Acoustic signals received in different directions produce amplitude distortions that vary with frequency. In addition, the radiated sound field is required to have small side lobes to avoid unwanted acoustic signals in non-target areas of the sound field. In order to achieve the above characteristics, an array composed of multip...

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Problems solved by technology

In order to make the electro-acoustic transducer array radiate a sound field that hardly changes with frequency and has certain directivity characteristics in a wide frequency range, in the prior art, if a relatively simple signal processing method is used, although it can achieve a wide frequency band that does not change with frequency directional characteristics, wide coverage or full coverage directional characteristics, but the directional characteristics with a specific beamwidth cannot be achieved; if complex signal processing methods are used, the directional characteristics of broadband that do not change with frequency can be achieved, and a specific beamwidth can be achieved The method usually uses a weighting function that changes with frequency, and requires complex signal processing algorithms such as filtering, which increases the complexity of calculation

[0004] D.B. Keele Jr. proposed a constant beam width electroacoustic transducer array (CBT array) based on Legendre function weighting. Frequency-variable, radiated sound field with specific directivity and small side lobes. This method can use a simple weighting function that does not vary with frequency to realize a wide-band, frequency-invariant sound field with specific directivity characteristics and beam width , but this method is extended from the spherical crown CBT array, and can only achieve directivity with the shape of the Legendre function

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