超声换能器对线性调频信号脉冲压缩性能的影响分析*

该文研究了不同编码带宽下超声换能器对编码信号脉冲压缩后信噪比与轴向分辨率的影响关系。将脉冲压缩后的时域峰值转化为频域积分的形式，得到考虑换能器影响的脉冲压缩信噪比公式。以线性调频信号为例，仿真与实验结果表明，编码激励相对于方波激励的信噪比增益随编码带宽的减小而增大，因为受换能器带宽限制，编码激励的轴向分辨率随编码带宽的增大先减小后趋于稳定。该研究为编码激励方法更有效地应用于超声检测的背景中提供了参考。

Aanlysis of the influence of ultrasonic transducer on pulse compression performance of chirp signal

In this paper, the effects of ultrasonic transducer on the signal-to-noise ratio and axial resolution of coded signals after compression are studied under different coding bandwidths. The pulse-compressed time domain peak is converted into the form of frequency domain integral, and the pulse compression signal-to-noise ratio formula considering the influence of the transducer is obtained. Taking the chirp signal as an example, the simulation and experimental results show that the signal-to-noise ratio gain of the coded excitation relative to the square wave excitation increases with the decrease of the coding bandwidth. Because of the limitation of transducer bandwidth, the axial resolution of coded excitation method decreases first and then stabilizes with the increase of coding bandwidth. The research in this paper provides a reference for the application of coded excitation method in the background of ultrasonic detection.