Design and development of a MEMS butterfly resonator using synchronizing beam and out of plane actuation

This paper presents beam modeling techniques for maximizing mechanical sensitivity of a butterfly resonator for gyroscopic applications. We investigate the geometric aspects of synchronizing beam that connects the wings of a butterfly resonator. Our results show that geometric variation in the synchronizing beam can have a large effect on the frequency split and sensitivity of the device. The model simulation shows a sensitivity of \( 10^{ - 12} \)\( (m/^\circ /s) \) for a frequency split of 10 Hz resulting from the optimized synchronized beam. Out of plane actuation was developed to drive and sense the resonators displacement. Fabricated butterfly resonators were tested, and the experimental results show a frequency split of 305 Hz and 400 Hz while the model illustrated a split of 195 Hz and 330 Hz respectively. The design and analysis presented in this paper can further aid the development of MEMS butterfly resonators for inertial sensing applications.

     

Design of a novel RF MEMS square resonator

A novel kind of RF MEMS square resonator with a movable electrode structure that is driven by electrostatic force is proposed. Within the scope of the fabrication process allowed, the gap between the movable electrode and resonance square is decreased from 2.5 to 0.5 μm, which greatly reduces motional resistance so that resonator is easier to resonate. Then the DC driving voltage that makes electrode move setting displacement is deduced theoretically. The finite element simulation and analysis software ANSYS are used to validate mechanical vibration modal and determine center frequency of resonator. In addition, simulation of harmonic analysis is applied to obtain the change of output current and motional resistance before and after the electrode moving. Moreover, the design can also, to a certain extent, ease the difficulty of manufacturing the small gap in the micro-processing technology.     

A novel microfluidics integrated biosensor based on a MEMS resonator

Microsystem Technologies - In this paper a sensor based on MEMS resonators is proposed for digital microfluidics applications. The sensor system consists of a disk as active area immobilized for...     

Shape optimization of a dielectric resonator for improving its unloaded quality factor

A novel approach for shape optimization of dielectric resonators is presented with an objective of improving their unloaded quality factor. Shape (level‐set) and topology (topology gradient) optimization methods coupled with finite element method are utilized together, which as a result, relaxes the traditional trade‐off made between the spurious‐free band (isolation) and the high unloaded quality factor of the resonators. The defined cost function is minimized by the proposed iterative coupling between the level‐set method and the topology gradient method. The optimized resonator, which improves the unloaded quality factor of about 65% compared with the reference, is then approximated for fabrication. The reference, optimized, and approximated resonators are fabricated and measured. Results from the simulated and the fabricated resonators validate the optimization approach presented in this work. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

孔隙热弹性梁的非线性气弹性特性

根据作者由Hamilton变分原理导出的一个孔隙热弹性梁的非线性数学模型和气弹性原理中的一阶修正线性活塞理论,本文首先给出了位于高速或者超高速流动中两端固定的平面孔隙热弹性梁的控制微分方程和定解条件,其中基本未知量是梁的轴向和横向位移以及孔隙百分比和温度变化引起的“力矩”.为了考察孔隙热弹性梁在横向载荷和气弹性载荷联合作用下的非线性力学特性,采用微分求积方法对问题进行空间离散,得到一组关于时间的非线性常微分方程,然后在给定初始条件下采用变步长Runge-Kutta方法对方程组进行数值求解,由此研究了孔隙热弹性梁的气弹性特性,考察了参数的影响,得到了一些有益的结论.     

Design and analysis of perforated MEMS resonator

Microsystem Technologies - In this paper, we have designed an optimal design of microelectromechanical (MEMS) resonator. The paper explains the idea of suitable design, modeling and optimization of...     

超高频体模式MEMS谐振器及其传感系统平台技术研究

针对体模式MEMS谐振器激励和响应信号的特点,设计集成了激励信号产生和微弱信号检测的传感测量系统。系统通过对谐振器的扫频激励和检测响应信号,可以准确测量谐振器的谐振频率和Q值特性。为了有效测量谐振器产生的高频微弱位移电流信号,系统设计使用频谱搬移的测量方法。该方法通过把包含在高频信号中的有效信息搬移到低频端进行信号处理,可以提高信号抗噪声的能力,实现对微安量级的高频电流放大检测。     

Design and analysis of a novel MEMS spiral inductor with high quality factor

Microsystem Technologies - In this paper a novel spiral inductor with high quality (Q)-factor is presented. Non-uniform current density distribution, especially in inner turn, increases the...     

MEMS switches controlled multi-split ring resonator as a tunable metamaterial component

Based on the multisplit-ring resonator (MSRR) with MEMS switches, a tunable metamaterial component is proposed in this paper to realize multiband applications. Numerical simulations are carried out to verify the tunable capacity of the proposed structure. The simulated results show that the resonance frequency of the metamaterial component shifts to higher frequencies when the MEMS switches are at different states, and depends strongly on the place, state and microbeam height of MEMS switches. Moreover, the large tunable range can be obtained by controlling the up state or down state of MEMS switches, while the small tunable range can be obtained by controlling microbeam height of MEMS switches. That is, such controlling ways can realize both rough and minor tunable metamaterial component. The tunable method proposed in this paper is of great practical values in designing tunable metamaterial and negative refractive index material.     

Characterization of selective polysilicon deposition for MEMS resonator tuning

Variations in micromachining processes cause submicron differences in the size of MEMS devices, which leads to frequency scatter in resonators. A new method of compensating for fabrication process variations is to add material to MEMS structures by the selective deposition of polysilicon. It is performed by electrically heating the MEMS in a 25/spl deg/C silane environment to activate the local decomposition of the gas. On a (1.0/spl times/1.5/spl times/100) /spl mu/m/sup 3/, clamped-clamped, polysilicon beam, at a power dissipation of 2.38 mW (peak temperature of 699/spl deg/C), a new layer of polysilicon (up to 1 /spl mu/m thick) was deposited in 10 min. The deposition rate was three times faster than conventional LPCVD rates for polysilicon. When selective polysilicon deposition (SPD) was applied to the frequency tuning of specially-designed, comb-drive resonators, a correlation was found between the change in resonant frequency and the length of the newly deposited material (the hotspot) on the resonator's suspension beams. A second correlation linked the length of the hotspot to the magnitude of the power fluctuation during the deposition trial. The mechanisms for changing resonant frequency by the SPD process include increasing mass and stiffness and altering residual stress. The effects of localized heating are presented. The experiments and simulations in this work yield guidelines for tuning resonators to a target frequency.     

Fabrication and characterization of zinc oxide piezoelectric MEMS resonator

Microsystem Technologies - Micro electromechanical system resonators (MEMS) are being explored to fulfil the demands of speedy wireless communication circuits, which may be utilized as oscillators...     

MEMS圆盘谐振器形变对电气刚度影响分析

电气刚度是影响MEMS谐振器谐振频率精度的因素之一。但是对于谐振器受到应力时,产生的形变量对电气刚度的影响的理论研究报道甚少。鉴于此,本文对电容式盘结构谐振器受径向静电力和纵向惯性力下的形变量以及电气刚度的改变量进行了系统的理论分析。研究结果表明,当圆盘与电极间隙为50 nm,且电压达到50 V时,圆盘由于静电力产生的径向形变量可达间隙的2.05%,电气刚度改变6.15%。当圆盘半径为100μm,且受到10 000 gn的纵向惯性力时,其最大形变量可以达到圆盘厚度的2.4%,电气刚度改变2.4%。本文分析结果对其他盘结构谐振器的分析亦有重要借鉴意义。     

Optimal control of thermoelastic beam vibrations by piezoelectric actuation

This paper presents the vibrations suppression of a thermoelastic beam subject to sudden heat input by a single piezoelectric actuator. An optimization problem is formulated as the minimization of a quadratic functional in terms of displacement and velocity at a given time and with the least control effort. The solution method is based on a combination of modal expansion and variational approaches. The modal expansion approach is used to convert the optimal control of distributed parameter system into the optimal control of lumped parameter system. By utilizing the variational approach, an explicit optimal control law is derived and the determination of the corresponding displacement and velocity is reduced to solving a set of ordinary differential equations. Numerical results are presented to demonstrate the effectiveness and the applicability of the proposed method.     

嵌套环式MEMS振动陀螺的静电修调算法

对于工作在n=2模态谐振结构,静电修调是一种消除频率裂解、实现模态匹配的常用方法.基于环形谐振子的刚度扰动模型,提出了一种直观而实用的修调算法.通过巧妙地近似,并将嵌套环结构的内置修调电极等效为两簇簇带负刚度的“径向弹簧”,从而将单环谐振结构的理论模型成功应用于多环嵌套结构.最后通过静电修调实验对该算法进行了验证,实现了带误差谐振子的模态匹配.实验结果表明:通过该算法频率裂解从15 Hz左右被修到0.03 Hz左右.     

Quad notch UWB antenna using combination of slots and split‐ring resonator

A novel coplanar waveguide fed UWB antenna with quad notch band characteristics has been proposed in this work. The antenna layout is designed based on a combination of well‐known geometrical shapes: a half ellipse patch, rectangle, and triangle. The shape of the ground plane is partially tapered rectangular. The overall dimension of the antenna is 41.5 × 32 mm. The antenna uses three U‐shaped slots at the top surface to create three notched band characteristics. A split‐ring resonator is then introduced at the bottom surface of the antenna. With the integration of split‐ring resonator at the bottom surface, an additional notch band at 7.25 to 7.75 (6.7%) GHz is created in the antenna. The designed antenna has an operating impedance bandwidth (VSWR ≤2) ranges from 3.03 to 12.34 GHz except in quad frequency stop bands of 3.3 to 3.7 (11.4%), 5.15 to 5.35 (3.8%), 5.725 to 5.825 (1.7%), and 7.25 to 7.75 (6.7%) GHz. The proposed antennas are successfully designed, prototyped, and measured. The simulated and measured results are extensively studied and discussed. Correlation between the time‐domain transmitting antenna input signal and the received antenna output signal is calculated in order to ensure that the proposed antenna can be used in pulse‐communication systems. This antenna finds applications in medical imaging, military radar systems, and other common UWB applications.     

等效模型分析微机械薄膜谐振器的力学特性

通过引入折合的概念,将多层微机械谐振悬臂梁等效为单层结构,建立了多层微悬臂梁的弯曲振动方程,结合边界条件求出了微悬臂梁的固有频率。等效概念的引入大大简化了多层微机械谐振器件振动特性的理论分析过程,与传统只考虑绝对占优层的方法相比,等效模型不仅更加精确,而且突出了多层微机械谐振梁中的主要矛盾,为多层微机械谐振式器件的结构优化设计奠定了基础。     

Design of wideband bandpass filter using short‐circuited circular patch resonator loaded with slots

This paper presents a wideband bandpass filter design based on a short‐circuited circular patch resonator with inductively loaded slots. The cavity model method is used to analyze the excited resonances of the resonator. According to the illustration of the cavity model, the TM₀₁₀ mode is excited as the fundamental mode, the resonant frequency of which is much lower than that of the TM₁₁₀ mode and can be further lowered by the loaded arc‐oriented slots. Therefore, the proposed resonator can be used to design a filter with compact size. In addition, one of the two orthogonal degenerate TM₁₁₀ modes can be independently tuned by the slot along the symmetric plane without affecting the TM₀₁₀ mode. Since the resonant frequency of each mode can be tuned independently by the parameters of the slots, and the coupling between resonant modes of the resonator and source/load can be adjusted by the feeding angle and the capacitive loaded stubs on the feeding lines, the center frequencies and bandwidths of the designed bandpass filters can be tuned easily. The analysis is theoretically and experimentally verified by two examples with good agreement between the simulated and measured results.