一种低旁瓣圆形活塞高频换能器研究

Research on low side lobe circular piston high-frequency transducer

文章主要研究了一种低旁瓣圆形活塞高频换能器,采用去环非均匀分布方法实现低旁瓣,推导了去环非均匀圆形活塞换能器的指向性函数表达式,建立了指向性仿真模型,并采用Matlab软件进行仿真优化,对不同去环位置和不同去环宽度的圆形活塞换能器旁瓣级变化规律进行了分析,并通过添加匹配层拓展带宽。制作了一款低旁瓣圆形活塞宽带高频换能器,并进行测量。实测结果与仿真基本一致,换能器实测最大旁瓣级为−22.4 dB,较均匀圆形活塞换能器旁瓣级降低了4.8 dB,中心频率为325 kHz,−3 dB带宽为150 kHz。

In this paper,the circular piston high-frequency transducer with low side-lobes is studied.The low side-lobe is realized by the non-uniform ring-removal method for the circular piston transducer and the corresponding directivity expression is derived.The directivity simulation model of non-uniform ring-removed circular piston transducer is established and optimized with Matlab.The variation of side-lobes with ring-removed position and width on the circular piston transducer is analyzed,and the bandwidth is expanded by adding matching layer.The low side-lobe broadband circular piston high-frequency transducer is prepared and measured,and the measurement results are basically in agreement with the simulation results.The measured maximum side-lobe of the transducer is−22.4 dB,which is 4.8 dB lower than that of the uniform piston array.The measured center frequency of the transducer is 325 kHz,and the−3 dB bandwidth is 150 kHz.