检索结果-内蒙古大学图书馆

Calculation of surface acoustic waves in a multilayered piezoelectric structure

Journal of Semiconductors 2013年第1期34卷 6-11页

作者：张祖伟温志渝胡晶 Key Laboratory of Fundamental Science on Micro/Nano-Device and System Technology Chongqing University National Center for International Research of Micro/Nano-System and New Material Technology Chongqing University Microsystem Research Center Chongqing University

The propagation properties of the surface acoustic waves（SAWs） in a ZnO-SiO2-Si multilayered piezoelectric structure are calculated by using the recursive asymptotic *** phase velocities and the electromechanical coupling coefficients for the Rayleigh wave and the Love wave in the different ZnO-SiO2-Si structures are calculated and *** Love mode wave is found to be predominantly generated since the c-axis of the ZnO film is generally perpendicular to the *** order to prove the calculated results,a Love mode SAW device based on the ZnO-SiO2-Si multilayered structure is fabricated by micromachining,and its frequency responses are *** experimental results are found to be mainly consistent with the calculated ones,except for the slightly larger velocities induced by the residual stresses produced in the fabrication process of the *** deviation of the experimental results from the calculated ones is reduced by thermal annealing.

关键词： SAW RAM multilayered structure

来源：评论

学校读者我要写书评

暂无评论

Smearing model and restoration of star image under conditions of variable angular velocity and long exposure time

Smearing model and restoration of star image under condition...

引用

作者： Sun, Ting Xing, Fei You, Zheng Wang, Xiaochu Li, Bin Department of Precision Instrument Tsinghua University Beijing 100084 China State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua University Beijing 100084 China Collaborative Innovation Center for Micro/Nano Fabrication Device and System Tsinghua University Beijing 100084 China

The star tracker is one of the most promising attitude measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker. © 2014 Optical Society of America.

关键词： Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

The fabrication of vibration energy harvester arrays based on AlN piezoelectric film

引用

Journal of Semiconductors 2013年第11期34卷 79-82页

作者：尚正国李东玲温志渝赵兴强 Key Laboratory of Fundamental Science on Micro/Nano-Device and System Technology Chongqing University National Center for International Research of Micro/Nano-System and New Material Technology Chongqing University Microsystem Research Center of Chongqing University

： The fabrication and measurement results of the vibration energy harvester arrays based on the piezoelectric aluminum nitride （AlN） film are presented. The structure design and fabrication process of the device are introduced. The key material, the AIN film with crystal orientation （002）, was deposited by pulsed-DC magnetron sputtering and characterized by X-ray diffraction （XRD）. The resonant frequency, power out, and the open circuit voltage of the device are detected. The optimized load of 80 kΩ and a remarkable maximum power out of 30.4 μW are obtained when the acceleration of 0.9g （g is standard gravity acceleration） is applied. key words： A1N; crystal orientation; harvester arrays; vibration energy

关键词： AlN crystal orientation harvester arrays vibration energy

来源：评论

学校读者我要写书评

暂无评论

Low temperature Si/Si wafer direct bonding using a plasma activated method

引用

Journal of Zhejiang University-science C(Computers and Electronics) 2013年第4期14卷 244-251页

作者： Dong-ling LI Zheng-guo SHANG Sheng-qiang WANG Zhi-yu WEN National Key Laboratory of Fundamental Science of Novel Micro/Nano Device and System Technology Chongqing University MOE Key Laboratory of Optoelectronic Technology & Systems Chongqing University Microsystem Research Center Chongqing University

Manufacturing and integration of micro-electro-mechanical systems （MEMS） devices and integrated circuits （ICs） by wafer bonding often generate problems caused by thermal properties of materials. This paper presents a low temperature wafer direct bonding process assisted by 02 plasma. Silicon wafers were treated with wet chemical cleaning and subsequently activated by 02 plasma in the etch element of a sputtering system. Then, two wafers were brought into contact in the bonder followed by annealing in N2 atmosphere for several hours. An infrared imaging system was used to detect bonding defects and a razor blade test was carried out to determine surface energy. The bonding yield reaches 90%--95% and the achieved surface energy is 1.76 J/m2 when the bonded wafers are annealed at 350 ~C in N2 atmosphere for 2 h. Void formation was systematically observed and eli-mination methods were proposed. The size and density of voids greatly depend on the annealing temperature. Short O2 plasma treatment for 60 s can alleviate void formation and enhance surface energy. A pulling test reveals that the bonding strength is more than 11.0 MPa. This low temperature wafer direct bonding process provides an efficient and reliable method for 3D integration, system on chip, and MEMS packaging.

关键词： Low temperature Wafer direct bonding O2 plasma activation Surface energy Void formation

来源：评论

学校读者我要写书评

暂无评论

Study of high-precision earth sensor with triple-FOV

引用

Instrumentation 2014年第2期1卷 23-29页

作者： WANG Hongjian XING Fei YOU Zheng CHU Daping ZHENG Lungui Collaborative Innovation Center for Micro/Nano Fabrication Device and SystemTsinghua UniversityBeijing 100084P.R.China State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua UniversityBeijing 100084P.R.China Department of Precision Instruments Tsinghua UniversityBeijing 100084P.R.China Department of Engineering Electrical Engineering DivisionUniversity of CambridgeCambridge CB30FAU.K. School of Instrument and Electronics North University of ChinaTaiyuan 030051P.R.China

Earth sensors are widely used in spacecraft for attitude determination. They need to have a very large field of view(FOV)( > 120°) and relatively low accuracy while being used in the aircrafts around orbit. A triple-FOV infrared earth sensor is proposed in this paper. It uses three pieces of standard infrared detectors with a wavelength range of 14;16μm,to sense the horizontal circle by detecting the infrared light emitted from the earth. From which,the geocentric vector can be obtained. A mathematic model is established and a validation model is set up to provide input parameters for the mathematic model. The simulation results of the two models show that the output of the mathematic model coincides with the known parameters. Based on the above analysis,a prototype has been built and tested. The test results show that the angle measurement error is about 0. 002° and hence such a triple-FOV earth sensor is capable to provide high-precision position information for autonomous navigation.

关键词： Earth Sensor Validation Model High Precision Autonomous Navigation

来源：评论

学校读者我要写书评

暂无评论

LONGITUDINAL WAVE RESONANT FREQUENCY CALCULATION AND VERIFICATION OF THE BULK ACOUSTIC RESONATOR

LONGITUDINAL WAVE RESONANT FREQUENCY CALCULATION AND VERIFIC...

引用

2013 5th IEEE International Conference on Broadband Network & Multimedia technology

作者： Yi HE Yang GAO Bin ZHOU Junru LI School of Information Engineering Southwest University of Science and Technology Institute of Electronic Engineering China Academy of Engineering Physics National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology Chongqing University

ISBN: (纸本)9781479900961

Thickness and material of electrode, piezoelectric and supporting layer film of the Film Bulk Acoustic Resonator (FBAR) are main influence factors of resonant frequency, desired resonance frequency can be achieved by confirming thickness and material. A formula about thickness, material, frequency parameter and angular frequency has been achieved by deriving stress-equation of motion in longitudinal wave of film bulk acoustic resonator;frequency parameter has been get from Newton iteration of determinant of stress and displacement boundary conditions, continuity equations simulated by MATLAB. The resonant frequency of a certain FBAR whose thickness, material and frequency parameter are determined has been calculated by the formula, and the calculation value is 1.441 GHz. Equivalent circuit of longitudinal vibration Mason model which has the same thickness, material with formula calculation has been simulated by ADS, and resonant frequency of simulation model is 1.473GHz. Verification simulation of equivalent circuit of longitudinal vibration Mason model shows: resonant frequency calculation value by formula and the simulation value of model are very close, and we can use the formula to calculate longitudinal wave resonance frequency of FBAR.

关键词： FBAR resonant frequency Newton iteration Mason model ADS simulation

来源：评论

学校读者我要写书评

暂无评论

Studies on Static Temperature Compensation for Vibrating Beam Accelerometer

Studies on Static Temperature Compensation for Vibrating Bea...

引用

2013 3rd International Conference on Mechanical Materials and Manufacturing Engineering(ICMMME 2013)

作者： Lishuang Feng He Wang Zhen Zhou Gongliu Yang Fundamental Science on Novel Inertial Instrument & Navigation System Technology Laboratory Beihang University Key Laboratory of Micro-nano Measurement-manipulation and Physics (Ministry of Education) Beihang University

Static temperature model identification and compensation of vibrating beam accelerometer(VBA)are studied in this *** relationships between scale factor K1,zero bias K0 with temperature are obtained through static rolling test in 1g-gravitational *** accelerometer static temperature model between-40℃to 60℃is established using the least square *** error model is used for temperature compensation of *** show that the precision of fitting RMS error is improved by an order of magnitude.

关键词： Vibrating Beam Accelerometer Static temperature model Temperature compensation

来源：评论

学校读者我要写书评

暂无评论

Theoretical analysis and concept demonstration of a novel MOEMS accelerometer based on Raman-Nath diffraction

引用

Journal of Semiconductors 2012年第4期33卷 51-56页

作者：张祖伟温志渝胡晶 Key Laboratory of Fundamental Science on Micro/Nano-Device and System Technology Chongqing UniversityChongqing 400030China National Center for International Research of Micro/Nano-System and New Material Technology Chongqing UniversityChongqing 400030China Microsystem Research Center of Chongqing University Chongqing 400030China

The design and simulation of a novel microoptoelectromechanical system （MOEMS） accelerometer based on Raman-Nath diffraction are presented. The device is planned to be fabricated by microelectromechanical system technology and has a different sensing principle than the other reported MOEMS accelerometers. The fun- damental theories and principles of the device are discussed in detail, a 3D finite element simulation of the flexural plate wave delay line oscillator is provided, and the operation frequency around 40 MHz is calculated. Finally, a lecture experiment is performed to demonstrate the feasibility of the device. This novel accelerometer is proposed to have the advantages of high sensitivity and anti-radiation, and has great potential for various applications.

关键词： accelerometer MOEMS Raman-Nath diffraction FPW delay line oscillator

来源：评论

学校读者我要写书评

暂无评论

Design and process test of a novel MOEMS accelerometer based on Raman-Nath diffraction

引用

Journal of Semiconductors 2012年第9期33卷 82-88页

作者：张祖伟温志渝尚正国李东玲胡晶 Key Laboratory of Fundamental Science on Micro/Nano-Device and System Technology Chongqing UniversityChongqing 400030China National Center for International Research of Micro/Nano-System and New Material Technology Chongqing University Chongqing 400030China Microsystem Research Center of Chongqing University Chongqing 400030China

A novel micro-opto-electro-mechanical system （MOEMS） accelerometer based on Raman-Nath diffraction is presented. It mainly consists of an FPW delay line oscillator and optical strip waveguides. The fun- damental theories and principles of the device are introduced briefly. A flexural plate-wave delay-line oscillator is designed to work as an acousto-optic （AO） shifter, which has a Klein-Cook parameter of 0.38. Single-mode optical strip waveguides of 2 μm in width and thicknesses of 0.6 μm are designed by using the effective index method for light transmission. The E^y00 mode waveguide polarizers are designed to ensure the consistency of the light polarization in the waveguides. The fabrication process, based on （100） oriented, 450-#m-thick silicon wafers is proposed in detail, and some difficulties in the process are discussed carefully. At last, a series of process tests are undertaken to solve the proposed problems. The results indicate that the proposed design and fabrication process of the device is dependable and realizable.

关键词： accelerometer MOEMS Raman-Nath diffraction design process test

来源：评论

学校读者我要写书评

暂无评论

Structural Design of a Compact in-Plane nano-Grating Accelerometer

引用

Chinese Physics Letters 2012年第11期29卷 219-223页

作者： YAO Bao-Yin ZHOU Zhen FENG Li-Shuang WANG Wen-Pu WANG Xiao Key Laboratory of Micro-nano Measurement-manipulation and Physics(Ministry of Education) Beihang UniversityBeijing 100191 Fundamental of Science on Novel Inertial Instrument&Navigation System Technology Laboratory Beihang UniversityBeijing 100191

A combination of large mass,weak spring and nano-grating is the key for a nano-grating accelerometer to measure nano-G acceleration.A novel compact nano-grating accelerometer integrating a large mass with nano-grating is ***,the numbers of diffraction orders are ***,structure parameters are optimized by finite element analysis to achieve a high sensitivity in an ideal vibration ***,we design the fabrication method to form such a compact nano-grating accelerometer and successfully fabricate the uniform and well-designed nano-gratings with a period of 847 nm,crater of 451 nm by an FIB/SEM dual beam *** on the ANSYS simulation,a nano-grating accelerometer is predicted to work in the first modal and enables the accelerometer to have displacement sensitivity at 197 nm/G with a measurement range of±1 G,corresponding to zeroth diffraction beam optical sensitivity 1%/*** nano-gratings fabricated are very close to those designed ones within experimental error to lay the foundation for the sequent *** results provide a theoretical basis for the design and fabrication of nano-grating accelerometers.

关键词： accelerometer beam integrating

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：