• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control >An Investigation of Lateral Modes in FBAR Resonators
【24h】

An Investigation of Lateral Modes in FBAR Resonators

机译：FBAR谐振器横向模式的研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Using first principles and the constitutive equations for a piezoelectric, we solve the 2-D acoustic wave inside a single, infinite, piezoelectric membrane to study the dispersion of thin film bulk acoustic resonator (FBAR) lateral modes, with and without infinitely thin electrodes. The acoustic eigenfunction is a dual wave, composed of longitudinal and shear components, able to satisfy the 2-D acoustic boundary conditions at the vacuum interfaces. For the single piezoelectric slab, we obtain analytical expressions of the dispersion for frequencies near the longitudinal resonant frequency (Fs) of the resonator. These expressions are more useful for the understanding of dispersion in FBARs and more elegant than numerical methods like finite-element modeling and various matrix methods. We additionally find that the interaction between the resonator’s electrodes and the acoustic wave modifies the lateral-mode dispersion when compared to the case with no electrodes. When correctly accounting for these interactions, the dispersion zero is placed clearly at Fs, unlike what is calculated from a 2-D model without electrodes where the dispersion zero is placed at Fp. This is important since all experimental evidence of measures FBAR resonators shows that the dispersion zero is at Fs. Furthermore, we introduce an electrical current-flow model for the propagating acoustic wave inside the electroded piezoelectric, and based on this model, we can discuss an electrode-loss mechanism for FBAR lateral modes which depends on dispersion. From our model, it results that lateral modes with real have higher electrode dissipation if they are closer to the resonant frequency. This is consistent with the typical behavior of measured FBAR filters where the maximum lateral mode damage on the insertion loss takes place for frequencies immediately below Fs.
机译：使用压电的第一原理和本构方程，我们在单个无限压电膜内求解二维声波，以研究带有或不带有无限薄电极的薄膜体声波谐振器（FBAR）横向模式的色散。声本征函数是一个双波，由纵向分量和剪切分量组成，能够满足真空界面的二维声边界条件。对于单个压电板，我们获得了谐振器纵向谐振频率（Fs）附近的频率色散的解析表达式。这些表达式对于理解FBAR中的色散更为有用，并且比诸如有限元建模和各种矩阵方法之类的数值方法更为优美。我们还发现，与没有电极的情况相比，谐振器的电极与声波之间的相互作用会改变横向模式的色散。当正确考虑这些相互作用时，色散零清晰地放置在Fs上，这与从没有电极的二维模型中将色散零放置在Fp上计算得出的结果不同。这很重要，因为所有测量FBAR谐振器的实验证据都表明，色散零在Fs处。此外，我们介绍了用于电极压电体内传播的声波的电流模型，并基于该模型，我们可以讨论依赖于色散的FBAR横向模式的电极损耗机理。从我们的模型中可以得出，如果真实模式的横向模式更接近谐振频率，则它们的电极耗散会更高。这与测量的FBAR滤波器的典型行为一致，在该行为中，紧接在Fs以下的频率对插入损耗造成最大的横向模破坏。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号