Tunability of Aluminum Nitride Acoustic Resonators: A Phenomenological Approach
Tunability of Aluminum Nitride Acoustic Resonators: A Phenomenological Approach
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DOI：
10.1109/tuffc.2011.2114
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发表时间：
2011-12-01
影响因子：
3.6
通讯作者：
Devos, Arnaud
中科院分区：
文献类型：
--
作者：
Defay, Emmanuel;Ben Hassine, Nizar;Devos, Arnaud
提出了一种现象学方法来确定导致氮化铝(AlN)声谐振器直流电压诱导可调谐的物理参数。这些谐振器的典型谐振频率从-200V时的2.038 GHz到+200V时的2.062 GHz不等。这表明，基于这些射频测量与直流偏置和所使用的模型，AlN刚度随DC偏置的变化是显著的，因为共振和反共振在400V时分别经历了相似的变化，24 MHz和19 MHz。皮秒超声波也被用来独立地证明声速(因此AlN刚度)对DC偏置很敏感，并且引起的变化与从共振测量中提取的变化相当。结果表明，在1V/µm的电场下，从皮秒超声提取的电场的相对刚度变化为54ppm.mum/V，这与从射频测量中提取的值57.2ppm.mum/V很好地吻合。这些AlN谐振器的总可调谐性达到1.1%，这是一个有趣的数字，虽然可能不够高，但对于实际应用来说可能不够高。
A phenomenological approach is developed to identify the physical parameters causing the dc-voltage-induced tunability of aluminum nitride (AlN) acoustic resonators, widely used for RF filters. The typical resonance frequency of these resonators varies from 2.038 GHz at -200 V to 2.062 GHz at +200 V. This indicates, based on these RF measurements versus dc bias and the model used, that the AlN stiffness variation versus dc bias is the prominent effect because both resonance and antiresonance experience a similar variation, respectively, 24 MHz and 19 MHz at 400 V. Picosecond ultrasonics were also used to prove independently that the acoustic velocity (and therefore AlN stiffness) is sensitive to dc bias and that the variation induced is comparable to that extracted from the resonance measurements. It turned out that the stiffness relative variation for an electric field of 1 V/mu m extracted from picosecond ultrasonics is 54 ppm.mu m/V. This is in good agreement with the value extracted from the RF measurements, namely 57.2 ppm.mu m/V. The overall tunability of these AlN resonators reaches 1.1%, which is an interesting figure, although probably not high enough for genuine applications.