研究了含初应力压电薄膜体声波谐振器(FBAR)厚度剪切振动的谐振特性.利用含初应力压电材料的压电弹性基本方程,推导出理想FBAR在正弦激励电压作用下的振动方程.然后根据边界条件,求出问题的解,得到了串联和并联谐振频率,并讨论了初应力对谐振频率、带宽和有效机电耦合系数的影响.给出了具体的数值算例,所得结果对于提高和改善FBAR的性能有参考意义.
This paper studied the resonance properties of Film Bulk Acoustic Resonator (FBAR) with initial stress in thickness-shear mode.Based on the fundamental piezoelastic equations of piezoelectric material with initial stresses,the vibration equation of ideal FBAR under sine excitation voltage is derived.The solution is then obtained by using the boundary conditions.The series and parallel resonance frequency are listed,and the effects of initial stresses on resonance frequency,bandwidth,and effective electromechanical coupling coefficient are discussed.A numerical example is presented to show the effects.These results are very useful for the improvement of FBAR performance.