基于互导纳原理的梳状传感器优化设计

Optimization of Comb Transducer Based on Mutual Admittance Principle

为优化梳状表面波传感器最佳结构参数,达到提高接收信号的幅值、减少波形拖尾现象的目的,提出了一种基于交互导纳概念的优化设计方法,对等间距梳状表面波传感器的幅频特性进行优化.采用数值模拟的方法,在铝板上激励表面波,并通过仿真分析梳状传感器阵元个数、阵元宽度及阵元间距等关键参数对接收信号波形与幅值的影响.单阵元宽度较小时,拖尾现象较弱;随着阵元个数的增加,接收信号幅值虽有所提高,但会产生较为严重的拖尾现象.梳状表面波传感器阵元间距与激励波长的比例系数对接收信号的幅值影响较大,通过互导纳原理并结合时频分析,确定了当阵元间距等于激励波长时,梳状表面波传感器激励信号较好.

An optimization design method based on mutual admittance principle was proposed in this paper. In order to improve the amplitude of the received signal and to reduce the ringing tail phenomenon,the time-frequency features of the equal spaced transducer array should be optimized upon the structural parameters. Based on the numerical simulation, a surface wave was excited on an aluminium plate. The key parameters,such as element spacing,element width and element number of comb transducer,which would affect the amplitude and the waveform of the received signals significantly,were analysed through the finite element method. The tail phenomenon is weak when the width of single element is small. And the amplitude of received signals increase with the element number,however,the waveform tail gets stronger. The ratio of element spacing versus the excitation wavelength of comb surface wave transducer possesses great influence on the amplitude of received signal. The received signal of comb surface wave transducer is better when the array element spacing is equal to the excitation wavelength based on the mutual admittance principle and the time-frequency analysis.