线性调频信号激励超声换能器的方法研究

针对超声换能器的特性,研究等幅及包络调制线性调频波的换能器激励响应。通过对比激励前后脉冲压缩的主瓣峰值、?3d B主瓣带宽和峰值旁瓣水平,探讨通过换能器后其信噪比和分辨率的性能。理论分析和仿真实验结果表明,两种调频信号通过换能器后信噪比和分辨率都减少,峰值旁瓣有所提高。包络调制线性调频信号激励换能器脉冲压缩的信噪比和分辨率高于等幅线性调频信号,但能量损失比等幅线性调频信号大。

The research of ultrasonic transducer excited by chirp signal

In this paper, the dynamic responses of the transducer to the equal amplitude chirp and envelope modulated chirp pulse excitation are studied. By comparing the main lobe peak values,-3dB bandwidths of the main lobes and the peak side-lobe-levels under the two pulse excitation signals, the performances of SNRs and resolutions corresponding to the two signals are analyzed. The results of theoretical analysis and simulation experiment show that the SNRs and resolutions of the two signals after transducer decreased, but peak side-lobe-levels improved. Compared with the equal amplitude chirp pulse excitation, the SNR and resolution of envelope modulated chirp pulse excitation after transducer is greater, while the corresponding energy loss is higher.