新型磁驱动增大检测电容的高精度MEMS惯性传感器研究

增大传感器振子的质量和静态测试电容可以减小电容式MEMS惯性传感系统的噪声,而深度粒子反应刻蚀工艺由于复杂的工艺原因,当深宽比较大时,不能刻蚀出大质量和大初始电容的传感器.据此,本文研究了一种磁驱动增大检测电容的MEMS惯性传感器,通过电磁驱动器,传感器的静态测试电容可以大幅增加,在梳齿电容上刻蚀阻尼槽后,其机械噪声达到0.61μg每根号赫兹,仿真其共振频率为598Hz,静态位移灵敏度为0.7μm每重力加速度,基于硅 玻璃键合工艺,制作了栅形条电容式惯性传感器,并用电磁驱动的方式测试其品质因子达到715,从而验证了制作工艺的可行性和电磁驱动器改变传感器初始静态测试电容的可行性.     

新型双向电容式MEMS加速度计特性分析

文章研究了一新型的栅形条电容MEMS加速度计,通过新型结构设计降低了传感器的机械噪声和电子噪声。用软件ANSOFT-Maxwell对栅形条电容的宽度、厚度及叠加宽度对检测电容的影响进行了分析。用深度离子刻蚀工艺和硅-玻璃键合工艺制作了传感器,初步测试结果表明其在X和Y方向的灵敏度分别为0.53pF/g 、0.49pF/g。制作的栅形条谐振子在大气下的品质因子达到514,说明栅形条结构可大大降低机械噪声。     

一种具有应力隔离结构的扭摆式电容加速度计

基于硅-玻璃键合工艺的扭摆式加速度计,其信号输出对扭转梁上的应力极敏感,而微加工过程中由于硅、玻璃两种材料热膨胀系数不匹配,会在扭转梁上引入较大的热应力,进而引起加速度计温度漂移。为此,提出一种具有应力隔离结构的扭摆式电容加速度计。通过缓冲折叠梁和内支撑框架的优化组合,使热应力难以传递到扭转梁上,从而有效降低加速度计的温度漂移。使用ANSYS软件对加速度计进行了模态和热应力分析,结果表明:工作模态的固有频率为1 352 Hz,远小于其他干扰模态的频率;加速度计的灵敏度为0.386pF/g(g=9.8m/s2);相同条件下,不带隔离结构的扭摆加速度计的热应力主要集中在扭转梁的末端,其最大应力约100 MPa;具有应力隔离结构的加速度计,其热应力主要集中在缓冲折叠梁上,而扭转梁上的应力约为1.7 MPa,仅为前者的1.7%。采用硅-玻璃键合和电感耦合等离子体(ICP)刻蚀工艺,完成了加速度计芯片的制作。     

一种新型基于交指电容和微带电感的单层低成本宽带带通滤波器

随着无线通信系统的快速发展,尤其是5G时代的来临,带通滤波器作为射频前端的选频器件被广泛应用于各种系统.近年来,人们对通信的需求日益提升,因此滤波器的小型化、低成本以及高性能等方面的要求成为业内研究的重点.现代工艺技术的发展为带通滤波器的设计提供了多种方法,如使用阶跃阻抗谐振器设计微带带通滤波器、利用互补开环谐振器作为基本谐振单元构造宽带带通滤波器和基于E型双模谐振器设计微带带通滤波器等.然而,这些微带滤波器的尺寸较大,令实现小型化的目标难以实现.由于集总元件具有体积小、成本低、带宽宽、元件间相互作用小等优点,在射频器件设计中发挥着重要作用.相较于基于集成无源器件（Integrated Passive Device,IPD）工艺和低温共烧陶瓷（Low-Temperature Co-fired Ceramic,LTCC）工艺的带通滤波器,这种单层宽带带通滤波器具有更低的生产成本、更少的损耗限制,以及避免了基于表面贴装器件的成本和制造公差等问题.由于其采用交指电容和微带电感的简单实现方式,该方法所设计的滤波器还具有工艺简单和体积小的优点.基于单层印刷电路板（Printed Circuit ...     

A novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances

The comb capacitances fabricated by deep reactive ion etching (RIE) process have high aspect ratio which is usually smaller than 30 : 1 for the complicated process factors, and the combs are usually not parallel due to the well-known micro-loading effect and other process factors, which restricts the increase of the seismic mass by increasing the thickness of comb to reduce the thermal mechanical noise and the decrease of the gap of the comb capacitances for increasing the sensitive capacitance to reduce the electrical noise. Aiming at the disadvantage of the deep RIE, a novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances is developed. One part of sensing of inertial signal of the micro-accelerometer is by the grid strip capacitances whose overlapping area is variable and which do not have the non-parallel plate's effect caused by the deep RIE process. Another part is by the sensing gap alterable capacitances whose gap between combs can be reduced by the actuators. The designed initial gap of the alterable comb capacitances is relatively large to depress the effect of the maximum aspect ratio (30 : 1) of deep RIE process. The initial gap of the capacitance of the actuator is smaller than the one of the comb capacitances. The difference between the two gaps is the initial gap of the sensitive capacitor. The designed structure depresses greatly the requirement of deep RIE process. The effects of non-parallel combs on the accelerometer are also analyzed. The characteristics of the micro-accelerometer are discussed by field emission microscopy (FEM) tool ANSYS. The tested devices based on slide-film damping effect are fabricated, and the tested quality factor is 514, which shows that grid strip capacitance design can partly improve the resolution and also prove the feasibility of the designed silicon-glass anodically bonding process.     

一个新型的大检测电容结构的MEMS惯性传感器研究

A novel MEMS inertial sensor with enhanced sensing capacitors is developed. The designed fabricated process of the sensor is a deep RIE process, which can increase the mass of the seismic to reduce the mechanical noise, and the designed capacitance sensing method is changing the capacitance area, which can reduce the air damping between the sensing capacitor plates and reduce the requirement for the DRIE process precision, and reduce the electronic noise by increasing the sensing voltage to improve the resolution. The design and simulation are also verified by using the FEM tool ANSYS. The simulated results show that the transverse sensitivity of the sensor is approximately equal to zero. Finally, the fabricated process based on silicon-glass bonding and the preliminary test results of the device for testing grid capacitors and the novel inertial sensor are presented. The testing quality factor of the testing device based on the slide-film damping effect is 514, which shows that the enhanced capacitors can reduce mechanical noise. The preliminary testing result of the sensitivity is 0.492pf/g.     

A novel MEMS inertial sensor with enhanced sensing capacitors

A novel MEMS inertial sensor with enhanced sensing capacitors is developed. The designed fabricated process of the sensor is a deep RIE process, which can increase the mass of the seismic to reduce the mechanical noise, and the designed capacitance sensing method is changing the capacitance area, which can reduce the air damping between the sensing capacitor plates and reduce the requirement for the DRIE process precision, and reduce the electronic noise by increasing the sensing voltage to improve the resolution. The design and simulation are also verified by using the FEM tool ANSYS. The simulated results show that the transverse sensitivity of the sensor is approximately equal to zero. Finally, the fabricated process based on silicon-glass bonding and the preliminary test results of the device for testing grid capacitors and the novel inertial sensor are presented. The testing quality factor of the testing device based on the slide-film damping effect is 514, which shows that the enhanced capacitors can reduce mechanical noise. The preliminary testing result of the sensitivity is 0.492 pf/g.     

一种新型的基于滑膜阻尼的电容式双向MEMS惯性传感器

设计了一个新型的结构完全对称的双向MEMS电容式惯性传感器.该传感器主要由可动质量块、栅形条、支撑梁、连接梁、阻尼调整梳齿组成.设计的结构采用变电容面积的检测方式,在降低空气阻尼的同时也降低了对DRIE工艺的要求,并通过加大测试信号电压来降低电路噪声,从而提高传感器的分辨率.用有限元工具ANSYS详细讨论了传感器的参数和性能,并模拟验证了设计的双向传感器的交叉效应近似为零.制作了滑膜阻尼测试器件,在大气压下,测得的品质因子可达514,验证了该结构设计可以提高传感器的分辨率和该工艺设计的可行性.     

一种新型的基于滑膜阻尼的电容式双向MEMS惯性传感器

设计了一个新型的结构完全对称的双向MEMS电容式惯性传感器.该传感器主要由可动质量块、栅形条、支撑梁、连接梁、阻尼调整梳齿组成.设计的结构采用变电容面积的检测方式,在降低空气阻尼的同时也降低了对DRIE工艺的要求,并通过加大测试信号电压来降低电路噪声,从而提高传感器的分辨率.用有限元工具ANSYS详细讨论了传感器的参数和性能,并模拟验证了设计的双向传感器的交叉效应近似为零.制作了滑膜阻尼测试器件,在大气压下,测得的品质因子可达514,验证了该结构设计可以提高传感器的分辨率和该工艺设计的可行性.     

针对电容型MEMS读出电路噪声与失调的优化

This paper presents a high precision CMOS readout circuit for a capacitive MEMS gyroscope. A continuous time topology is employed as well as the chopper noise cancelling technique. A detailed analysis of the noise and mismatch of the capacitive readout circuit is given. The analysis and measurement results have shown that thermal noise dominates in the proposed circuit, and several approaches should be used for both noise and mismatch optimization. The circuit chip operates under a single 5 V supply, and has a measured capacitance resolution of 0.2 aF/√Hz. With such a readout circuit, the gyroscope can accurately measure the angular rate with a sensitivity of 15.3 mV/°/s.     

Noise and mismatch optimization for capacitive MEMS readout

This paper presents a high precision CMOS readout circuit for a capacitive MEMS gyroscope. A continuous time topology is employed as well as the chopper noise cancelling technique. A detailed analysis of the noise and mismatch of the capacitive readout circuit is given. The analysis and measurement results have shown that thermal noise dominates in the proposed circuit, and several approaches should be used for both noise and mismatch optimization. The circuit chip operates under a single 5 V supply, and has a measured capacitance resolution of 0.2 aF/√Hz. With such a readout circuit, the gyroscope can accurately measure the angular rate with a sensitivity of 15.3 mV/°/s.     

微光机电加速度计的研究现状及发展(英文)

对目前正成为研究热点的微光机电(MOEMS)加速度计的原理和结构特点进行分析,总结了MOEMS加速度计的分类和发展趋势。针对微-纳光栅加速度计,分析了基于干涉效应的微米光栅加速度计和基于亚波长结构有效折射率变化的纳米光栅加速度计的结构和原理,其精度可达ng,并成功应用到地震监测中。重点分析了基于聚合物的新型光波导加速度计的结构和性能。微环谐振式加速度计测量精度高,性能可"裁剪",但长期稳定性是制约其应用的主要问题。光力加速度计利用原子进行加速度测量,克服了传统悬臂梁结构长期稳定性差的缺点,具有极高的测量精度。对这几种加速度计的技术特点和主要指标进行比较,并初步探讨了用于惯性领域中的MOEMS加速度计的发展方向和应用前景。     

97dB动态范围、带温度补偿的MEMS电容传感器读出电路

This paper presents a charge-sensitive-amplifier(CSA)based readout circuit for capacitive microelectro-mechanical-system(MEMS)sensors.A continuous-time(CT)readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits.An operational trans-conductance amplifier(OTA)structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal.An analog temperature compensation method is proposed,which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity.The chip is designed and implemented in a 0.35 m CMOS process and is 2.1 2.1 mm2in area.The measurement shows that the readout circuitachieves0.9aF/√Hz capacitive resolution,97dBd ynamic range in 100Hz signal bandwidth,and 0.8mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.