乐甫波器件的幅频特性研究

Research on Amplitude-frequency Characteristic of a Love Wave Device

乐甫波器件的设计制作过程中,幅频特性是其关键性能指标.本文基于部分波理论和表面有效介电常数方法建立乐甫波谐振频率的理论分析模型,计算乐甫波的传播速度、谐振频率及机电耦合系数;在此基础上通过在梅森等效电路中加入波导元件,得到乐甫波器件的等效电路模型,仿真出器件的幅频特性曲线;通过实际器件测试结果与数值仿真对比,验证了理论模型的有效性.仿真分析薄膜厚度变化对乐甫波器件幅频特性的影响,指导器件的设计制作和测试系统的搭建.

In the process of Love wave device＇s design and fabrication, the amplitude-trequency characteris- tic is its key performance index. Based on the partial wave theory and the surface effective permittivity meth- od, the theoretical analysis model of Love wave resonant frequency is established, the Love wave＇ s propagation velocity, resonant frequency and electromechanical coupling coefficient are calculated. The equivalent circuit model of a Love wave device is obtained by adding waveguide component in the Mason equivalent circuit, and the device＇s amplitude-frequency curve is simulated, accordingly. By comparison of the device＇s test results and the numerical simulation, the validity of the theoretical model is proved. The influence of the film thick- ness on the amplitude-frequency characteristic is analyzed, which can provide guidance to the device design, fabrication and the measurement system establishment.