MEMS降阶宏模型仿真平台研究

随着MEMS系统级设计成为研究的热点,MEMS系统级CAD的开发日益重要.论文介绍了一种基于降阶宏模型MEMS系统级仿真平台,通过有限元方法提取MEMS器件几何物理数据.建立MEMS器件有限元模型.利用Krylov子空间算法缩聚自由度建立宏模型,通过系统级仿真平台对此进行系统级仿真. 整个流程通过VC++编译器调用ANSYS、嵌入封装的算法动态链接库、集成SIMULINK系统仿真器完成.并用双端固支梁实例对所有模块加以验证,仿真结果准确,计算效率较高.     

分立活塞式MEMS微变形镜的系统级设计

利用实验室自主研发的集成设计平台,搭建了分立活塞式MEMS微变形镜的系统级行为模型,并对其有效性和准确性进行了验证;在此基础上完成了微变形镜的结构设计,并由仿真得到了结构的性能参数.研究结果表明,采用系统级方法进行MEMS器件的设计能够在确保求解精度的前提下,显著提高设计效率,缩短设计周期,减小设计成本;所设计的MEMS微变形镜的各项性能指标完全能满足一般自适应光学系统的应用要求.     

MEMS的设计方法与系统模拟

随着MEMS产业重点从单个的MEMS器件向MEMS系统产品的转移 ,MEMS系统级模拟变得日益重要 .文中主要介绍了MEMS系统的一些结构化、标准化的设计方法以及MEMS系统建模与模拟的分级 ,重点阐述了MEMS器件级与系统级模拟之间的桥梁———宏模型的建立及系统级模拟的实现。最后介绍了微加速度计系统模拟的一个例子     

面向三维实体建模的MEMS设计方法

根据"所见即所得"的设计理念,提出了一种面向三维实体建模的MEMS设计方法,实现了从三维实体到系统级模型或工艺版图的设计流程,使设计者可以首先直接建立器件的三维实体模型,在完成有限元分析后,可以通过组件映射和宏模型提取的方式获得系统级模型,再通过自动版图转换得到相应的工艺版图.此设计方法可以提高设计效率,并且保证了模型...     

用于系统级仿真的MEMS器件宏模型研究现状

微机电系统(MEMS)的未来在于有稳定数量且不断壮大的新型产品能成功地转化为商品,这关键在于将计算机引入到MEMS设计、制造全过程。阐述了MEMS CAD的复杂性和困难。对MEMS CAD的分层设计思想作了简要介绍,着重对现有的MEMS器件宏模型的建模方法和模型的描述与其国内外研究现状与发展方向进行介绍和总结,认为宏模型研究的重点将是器件非线性特性的有效表达和建模过程自动化的计算机实现,并对今后的研究发展提出一些建议。     

支持细粒度协作的CAD系统在线集成研究

研究了一种支持细粒度协作的遗产CAD系统的在线集成方法,提出通过中间件agent来封装单机CAD系统应用.构造了中间件agent的外封装器和内封装器结构,并描述其工作过程.设计了细粒度协作的通讯机制,并采用基于标准宏参命令的通讯协议来支持遗产CAD系统的集成.初步实现了一个集成两种遗产CAD应用的原型系统.     

基于Krylov子空间投影法的MEMS宏建模方法

基于Krylov子空间投影法结合有限元分析(FEA)建立了一种宏模型提取方法,以便能够在系统级快速地建立器件宏模型.这种方法通过对整个2D或3D器件有限元分析的结果提取宏模型.基于这种方法建立的宏模型具有计算代价低、精度合适的特点,而且能方便地插入到系统级仿真器进行仿真.文中通过一个谐振器结构阐释了这一方法,并且针对所建立的谐振器结构宏模型进行了精确性验证.     

CMOS-MEMS体硅集成陀螺的系统仿真

体硅MEMS和CMOS电路的单片集成技术是提高传感器性能的有效途径,但是集成技术会对陀螺的设计和CMOS电路的设计提出更高的要求.通过建立CMOS-MEMS体硅陀螺的等效电学模型,实现了对CMOS-MEMS体硅陀螺的系统级仿真.通过系统仿真,陀螺的结构部分、电路部分、集成产生的寄生效应以及工艺误差得到了有效的分析,从而能够了解它们相互之间的影响,更好的指导CMOS-MEMS体硅集成器件的设计.     

基于IP库的MEMS设计系统

针对MEMS设计系统中机械性能仿真不足、设计与加工脱节、缺少工艺验证等问题,借鉴了IC设计可重用思想,引入了具有知识产权的功能模块--IP的概念,提出了基于IP库的MEMS设计方法.该方法是Top-Down和Bottom-Up设计相结合的方法,其核心是MEMS IP库,关键技术包括IP库、虚拟工艺、虚拟运行等,分别对应IP管理、工艺级仿真系统以及器件行为级仿真系统.最后以电容式微加速度计设计为例,对双梁、四梁、疏齿等6种不同的结构分别进行了设计仿真、流水加工,封装和测试的过程,完成了器件从设计到成品的整个流程,验证了本文提出的设计方法和设计系统的有效性和正确性.     

具有空间连续行为的微型压力传感器系统级建模

大多数MEMS器件(如梁、膜等)的动态特性方程为偏微分方程,因此建立对应组件的可重用参数化行为模型是一个难题.本文通过有限差分法把偏微分方程转化为常微分方程组,然后采用混合信号硬件描述语言进行描述,解决了该问题.针对电容式微型压力传感器,专门考虑膜片的空间连续行为以及结构、静电力的耦合作用,建立了包含接口电路在内的系统模型,据此进行了动态行为仿真.通过结果对比,验证了方法的实用性.相对于通用的参数化组件模型,当前MEMS商业化软件多采用逐个器件进行宏模型抽取的方式实现系统级建模和仿真.     

梳齿谐振器宏模型的系统级应用

宏模型的获取是由Krylov子空间投影法结合器件级有限元分析的宏建模方法来实现,利用此模型和基于可重用IP设计思想的系统级组件建模方法建立由VHDL-AMS语言描述的梳齿谐振器系统级模型,在华大VDE仿真平台上搭建出了梳齿谐振器的系统模型,并进行一系列的仿真,包括时域阶跃、交流电压信号仿真和频域交流小信号仿真,仿真结果与商用仿真工具ANSYS仿真结果保持良好的一致.     

Numerical simulation and analysis of electrically actuated microbeam-based MEMS capacitive switch

The MEMS capacitive switch based on fixed-fixed microbeam has garnered significant attention due to their geometric simplicity and broad applicability. The accurate model which describes the multiphysical coupled-field of MEMS capacitive switch should be developed to predict their electromechanical behaviors. The improved macromodel of the fixed-fixed microbeam-based MEMS capacitive switch is presented to investigate the behavior of electrically actuated MEMS capacitive switch in this paper, the macromodel provides an effective and accurate design tool for this class of MEMS devices because of taking account into some effects simultaneously including fringing field effect, midplane stretching effect, residual stress and multiphysical coupled-field effect. The numerical analysis of mechanical characterizations of electrically actuated microbeam-based MEMS capacitive switch are performed by the finite element Newmark method, and the performances of static and dynamic of MEMS capacitive switch are obtained. The numerical results show that, with only a few nodes used in the computation, the FEM-Newmark gives the identical results to other numerical methods, such as the shooting method and experiments. Moreover, the proposed model can offer proper and convenient approach for numerical calculations, and promote design of MEMS devices.     

基于受力分析的MEMS薄膜系统级模拟方法的研究

介绍一种MEMS系统级模拟方法.该方法直接分析运动物体的受力情况,并结合能量原理,利用受控源的反馈实现耦合作用,建立机电耦合MEMS薄膜的等效电路模型.利用该等效电路实现对薄膜动态行为的系统级模拟,并将Spice和有限元法,Saber的模拟结果进行对比,验证了该模拟方法应用于二维情况分析的有效性.     

Chip-level integration of RF MEMS on-chip inductors using UV-LIGA technique

This paper presents a chip-level integration of radio-frequency (RF) microelectromechanical systems (MEMS) air-suspended circular spiral on-chip inductors onto MOSIS RF circuit chips of LNA and VCO using a multi-layer UV-LIGA technique including SU-8 UV lithography and copper electroplating. A high frequency simulation package, HFSS, was used to determine the layout of MEMS on-chip inductors with inductance values close to the target inductance values required for the RF circuit chips within the range of 10%. All MEMS on-chip inductors were successfully fabricated using a contrast enhancement method for 50 μm air suspension without any physical deformations. High frequency measurement and modeling of the integrated inductors revealed relatively high quality factors over 10 and self-resonant frequencies more than 15 GHz for a 1.44 nH source inductor and a 3.14 nH drain inductor on low resistivity silicon substrates (0.014 Ω cm). The post-IC integration of RF MEMS on-chip inductors onto RF circuit chips at a chip scale using a multi-layer UV-LIGA technique along with high frequency measurement and modeling demonstrated in this work will open up new avenues with the wider integration feasibility of MEMS on-chip inductors in RF applications for cost-effective prototype applications in small laboratories and businesses.     

Research development of measuring methods on the tribology characters for movable MEMS devices: a review

Micro electro-mechanical systems (MEMS) offers great promise for system integration of sensors, actuators and signal processing. However, to the movable MEMS devices, there have always been major obstacles to their realization and reliability in the past—tribology problems. Because of the size effect, the conventional frictional law is no longer feasible to MEMS devices. It is vital to do research on micro-tribology and rebuild a micro-tribology theory in which size effect must be concerned. At the same time, in order to obtain reliable experimental data to support the theory, a feasible measuring method is also necessary. This paper describes two kinds of measuring methods to realize this purpose—on-chip measuring method and off-chip measuring method. Advantages, disadvantages, research status and the application prospect of each kind of methods are all introduced. Finally, development prospect of measuring methods is mentioned.     

A reduced-order model for electrically actuated microbeam-based MEMS

We present an analytical approach and a reduced-order model (macromodel) to investigate the behavior of electrically actuated microbeam-based MEMS. The macromodel provides an effective and accurate design tool for this class of MEMS devices. The macromodel is obtained by discretizing the distributed-parameter system using a Galerkin procedure into a finite-degree-of-freedom system consisting of ordinary-differential equations in time. The macromodel accounts for moderately large deflections, dynamic loads, and the coupling between the mechanical and electrical forces. It accounts for linear and nonlinear elastic restoring forces and the nonlinear electric forces generated by the capacitors. A new technique is developed to represent the electric force in the equations of motion. The new approach allows the use of few linear-undamped mode shapes of a microbeam in its straight position as basis functions in a Galerkin procedure. The macromodel is validated by comparing its results with experimental results and finite-element solutions available in the literature. Our approach shows attractive features compared to finite-element softwares used in the literature. It is robust over the whole device operation range up to the instability limit of the device (i.e., pull-in). Moreover, it has low computational cost and allows for an easier understanding of the influence of the various design parameters. As a result, it can be of significant benefit to the development of MEMS design software.     

MEMS陀螺仪大失准角解耦测试方法的研究

针对传统陀螺仪测试方法不适用于MEMS陀螺仪测试的现状,分析了MEMS陀螺仪标度因数和输入轴失准角测试特点,在此基础上,提出了一种新的解耦测试方法;同时,设计了解耦测试夹具,并给出了解耦测试试验流程;最后采用MEMS陀螺仪典型试验参数进行了仿真.仿真表明,该方法实现了测试参数的解耦,提高了测量精度,适用于大输人轴失准角的MEMS陀螺仪.     

基于TPWL方法的MEMS热微执行器的热电耦合宏建模

本文给出了一种基于轨迹分段线性化TPWL( Trajectory Piecewise-Linear)方法的非线性热电耦合宏建模技术。首先建立了MEMS热微执行器的三维非线性热电耦合模型,并采用有限元方法对其进行空间离散,然后利用新的基于全局最大误差控制的线性化点选择算法获得一组线性化点,最后使用TPWL方法构造MEMS热微执行器的热电耦合宏模型。以平板式热微执行器为例,研究了宏模型的精度、效率及可扩展性。与全模型仿真结果进行比较,宏模型仿真结果的相对误差可达到0.036%,加速比可达到100倍以上。     

Fuzzy macromodel for dynamic simulation of microelectromechanical systems

This paper proposes an efficient approach that consists of an experimental design and a fuzzy-logic model (FLM) to generate macromodels for the simulation of microelectromechanical systems. Firstly, in the present approach, a force macromodel is adapted to perform the coupled simulations. Then, an experimental design is utilized to reduce the number of data needed for macromodel identification, and an FLM is chosen to fit the data. The identification scheme involves cluster estimation to determine the FLM structure and backpropagation method to efficiently obtain the FLM structure parameters that lead to an accurate macromodel. In order to verify the accuracy of the macromodel, the approach has been applied to a magnetic microactuator. The simulation results show that the force macromodel yielded errors of less than 1.5% for a 5-/spl mu/m displacement. Furthermore, the dynamic coupled simulation takes only several minutes. The results demonstrate the efficiency and effectiveness of the current approach.     

基于字级统计的功耗宏模型

文中提出的功耗宏模型建立在字级信号统计的基础上，可用于各种音／视频信号处理芯片的功耗估计，与比特级统计的拟合模型相比，具有更好的健装性，能在很大的信号变化范围内保持令人满意的计算精度；与门级模拟结果相比较，本模型的计算时间下降了2－3个数量级，而相对误差不超过20％，此外，这个模型可以区别不同的数字表示，给出低功耗的编码的优化效果。