高次谐波体声波谐振器谐振频率分布研究

基于由谐振频率分布提取压电薄膜参数的方法,研究影响高次谐波体声波谐振器(HBAR)谐振频率分布的因素。对多种HBAR进行模拟计算,模拟结果显示,变化基片对薄膜的声阻抗比值会引起并联谐振频率间隔的分布和有效机电耦合系数的分布改变;当薄膜的基模在高频时,改变电极对薄膜的声阻抗比值和电极厚度会引起谐振频率分布改变。这些结果表明,通过调整影响谐振频率分布的因素能使谐振频率变化,进而得到在特定的频率上产生谐振。

Study on distribution of resonance frequency of high-overtone bulk acoustic resonators

Based on the method of characterizing the piezo-fihns by the distribution of resonance frequency,the factors influencing the distribution of resonance frequency of High-overtone Bulk Acoustic Resonator (HBAR) consisting of a piezoelectric thin fihn with two electrodes and a substrate are studied.Some HBARs are simulated,the results manifest that changing the acoustic impedance ratio of the substrate to piezo-film the distribution of the space of the parallel resonance frequency and the effective electromechanical coupling factor are changed.When the fundamental mode of the piezo-film is at high frequency,changing the acoustic impedance ratio of the electrode to piezo-fihn and the thickness of the electrodes make the distribution of the resonance frequency of HBARs changed.These results manifest that the HBARs will be resonant at specific frequencies by the means of adjusting the factors affecting the distribution of the resonance frequency.