中文摘要：

基于阵元尺寸及间距变化对超声波束指向性的影响，分析了阵列换能器的指向性特征．针对要求波束指向特性指标严格的阵列换能器，研究了其阵元宽度和间距的变化对波束指向性的影响．结果表明，阵元尺寸差异对主波束的宽度无影响，增大阵元宽度可以增大声压幅值并提高接收信号的信噪比．阵元宽度和阵元间距同时变化对波束的指向性影响较大．经过对部分阵元间距及宽度变化的阵列换能器指向性的仿真实验，说明理论分析是可行的．

英文摘要：

The characteristics of linear phased arrays are studied by investigating the influence of element size on the ultrasonic beam steering properties. For the phased array transducer which has strict requirement on beam directivity index, the theory analysis indicates that the change of element width and spacing have effect on beam direction. It is shown that element width does not affect on the beamwidth of principal wave and large element width is of benefit to the high acoustic pressure and signal-to-noise; the simultaneous changes of element width and spacing have great influence on beam steering behavior. Finally, the beam directivity of linear phased arrays in which partial element width and spacing changes is simulated, the results agree well with theoretical analysis.