采用Fourier-Bessel方法对环型换能器的声场进行数值计算,并对仿真声场进行了深入讨论. 通过对换能器轴向声压分布的分析,针对声近场明显的扰动,提出一种新的方法对声场进行预处理,即利用小波多分辨率分析降噪,去除近场杂频率成分,提高声压幅度. 研究结果表明,小波分析技术能提高Bessel声场的基波成像质量,对于小波变换在Bessel超声成像中的应用提供了很好的依据.
The simulated sound field of an annular ultrasound transducer is given based on Fourier-Bessel series method. After analyzing the axial acoustic pressure, especially the near-field disturbance, wavelet multi-resolution analysis of the noise reduction is carried out for removing the near-field complex frequency components and increasing the sound pressure amplitude. The results show that the wavelet analysis technique can be used for improving the fundamental ultrasound imaging quality of Bessel field.
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