摘要
以部分波理论为基础建立了乐甫波的理论模型,并引入表面有效介电常数方法对乐甫波进行仿真分析。仿真得到的表面有效介电常数、传播模态、频散特性、机电耦合系数等曲线表明了乐甫波的传播特性。当薄膜厚度d和声波波长λ的比值d/λ相对较小时,乐甫波只有一种基本模态;随着d/λ的增大,高阶模态越来越多,且各高阶模态都有一个d/λ的最低截止值;乐甫波所有模态的传播速度均随着d/λ的增大而减小,且都在压电基片的表面波速度和薄膜介质的体切变波速度之间;乐甫波所有模态的机电耦合系数都是先随d/λ的增大而增大,达到某个最大值后,再随着d/λ的增大而减小并最终趋近于零。
The theoretical model of love wave is established on the basis of the partial wave theory.The surface effective permittivity method is introduced to analyze the love wave.Simulations of the surface effective permittivity,propagation modes,dispersion characteristics,electromechanical coupling coefficient curves show the propagation characteristics of love wave.When the ratio of the film thickness to the acoustic wavelength d/λ is relatively small,there is only one basic mode.With the increase of d/λ,more and more higher-modes appear,and they all have a minimum cut-off value of d/λ.The propagation velocities of all love wave modes decrease with the increase of d/λ,and they are between the surface wave velocity of the piezoelectric substrate and the shear wave velocity of the film.With the d/λ increasing,the electromechanical coupling coefficients of all modes are firstly increasing,then decreasing and eventually tend to zero.
出处
《压电与声光》
CSCD
北大核心
2011年第2期174-177,181,共5页
Piezoelectrics & Acoustooptics
基金
教育部博士点基金资助项目(200802871037)
关键词
乐甫波
表面有效介电常数
传播模态
机电耦合系数
传播速度
love wave
surface effective permittivity
propagation modes
electromechanical coupling coefficient
propagation velocity
