Lohfink Annette, Eccardt Peter-Christian
Siemens AG, Corporate Technology, PS 8, 81730 Munich Germany.
IEEE Trans Ultrason Ferroelectr Freq Control. 2005 Dec;52(12):2163-72. doi: 10.1109/tuffc.2005.1563260.
Using piston radiator and plate capacitance theory capacitive micromachined ultrasound transducers (CMUT) membrane cells can be described by one-dimensional (1-D) model parameters. This paper describes in detail a new method, which derives a 1-D model for CMUT arrays from finite-element methods (FEM) simulations. A few static and harmonic FEM analyses of a single CMUT membrane cell are sufficient to derive the mechanical and electrical parameters of an equivalent piston as the moving part of the cell area. For an array of parallel-driven cells, the acoustic parameters are derived as a complex mechanical fluid impedance, depending on the membrane shape form. As a main advantage, the nonlinear behavior of the CMUT can be investigated much easier and faster compared to FEM simulations, e.g., for a design of the maximum applicable voltage depending on the input signal. The 1-D parameter model allows an easy description of the CMUT behavior in air and fluids and simplifies the investigation of wave propagation within the connecting fluid represented by FEM or transmission line matrix (TLM) models.
利用活塞辐射器和极板电容理论，电容式微机械超声换能器（CMUT）的膜单元可用一维（1-D）模型参数来描述。本文详细介绍了一种新方法，该方法从有限元方法（FEM）模拟中推导出CMUT阵列的一维模型。对单个CMUT膜单元进行几次静态和谐波有限元分析，就足以得出等效活塞作为单元区域运动部件的机械和电气参数。对于一组平行驱动的单元，声学参数可作为复机械流体阻抗得出，这取决于膜的形状。主要优点是，与有限元模拟相比，CMUT的非线性行为更容易、更快地得到研究，例如，根据输入信号设计最大适用电压。一维参数模型便于描述CMUT在空气和流体中的行为，并简化了对由有限元或传输线矩阵（TLM）模型表示的连接流体中波传播的研究。
