MEMS扫描镜光学性能的圆片级自动检测系统设计

为快速准确地检测出一张硅片上数百个MEMS扫描镜的良品与次品,设计了一种自动测量系统.选用高精度二维位置敏感探测器(PSD)设备,设计其后置硬件电路并编写数据采集的程序.结合经典三角法测量角度的原理搭建自动检测系统,在室温和正常光照条件下,完成了MEMS扫描镜光学性能圆片级自动检测的实验.结果表明:该系统能够快速准确地同时对扫描镜的两个轴进行检测并给出结果.     

基于X射线脉冲星导航系统探测器研究

综述了基于X射线脉冲星导航系统探测器的原理,分析了现有的几种不同类型探测器的性能、测时特点和应用的局限性;给出了由多只探测器组成的探测器系统的原理设计,并分析了探测器系统的构成、安装方式以及处理电路;阐述了X射线脉冲星导航系统探测器在航天器导航中的应用以及国外应用先例,为基于X射线脉冲星导航系统探测器的研制提供有用的参考。     

紫外光谱响应度测量系统设计

由于目前的紫外辐射的定标测量存在测量误差大的缺点,采用热释电探测器作为基准探测器给被测探测器(GaN)进行定标,给出光谱响应度测量系统的设计原理,对高稳定度紫外光源系统、热释电电学定标系统、信号检测电路进行了详细的设计,分析计算机控制和软件处理系统部分功能构成,最后进行了单色仪的波长标定来证明系统的准确性。     

基于智能移动终端及蓝牙的金属探测器的研制

金属探测器是用来检测和探测金属的仪器,这里所设计的是感应平衡式金属探测器的一种。感应平衡式金属探测器首先发射探测电磁场,检测到的金属目标由于涡流效应会返回一个电磁场信号,对该信号进行提取,通过金属探测器内部电路对探测信号进行处理与分解,达到区分信号的要求。通过低功耗蓝牙连接移动终端和金属探测器,其中设计了一套通信协议实现金属探测器和移动终端之间的稳定数据传输,接着在移动终端设备上使用机器学习算法对接收信号作进一步的处理和区分,达到精确区分不同种类金属的目的。     

铌酸锂晶片热释电红外探测器设计及性能测试

通过红外热释电探测器工作原理的分析,采用合适的半导体加工工艺将铌酸锂晶体母材减薄,并对减薄后铌酸锂晶片进行溅射、镀膜将其制成红外敏感单元。选用CMOS放大器与匹配的电阻、电容组成前置放大电路,对热释电信号进行放大和转换;根据红外光谱吸收原理,在敏感单元前封装了窄带滤光片从而提高了敏感单元选择吸收的性能。将敏感单元、前置放大电路和窄带滤波片三部分封装在一个壳体内,红外探测器制作成功。设计了信号调理电路,对从探测器得到的热释电信号进行二次放大和滤波;搭建了探测器响应测试系统,对探测器的性能进行测试,测试验证了该探测器设计的合理性。     

数字式振动检测系统的设计与研究

介绍一种新颖光电数字振动检测系统及其特点,具体就振动检测系统的先学扫描系统、光栅探测器的工作原理和参数设计、检测系统的电路设计等方面作了详细阐述.     

微型金属探测器

本文推荐一款微型金属探测装置的设计。您只需花很少钱和几个休息日,就能成为一台小巧的腕式微型金属探测装置的主人。为您的考古、探宝活动增添一个好助手。上世纪60～70年代,使用差频原理(B.F.O)的金属探测装置应用十分普遍。在第一台商用探测器出现后不久,某些型号的金属探测器销量增加了上千倍。后来,由于性能更好的感应平衡(I.B)和脉冲感应(P.I)型金属探测器在市场上出现,差频式金属探测器很快就不再流行了。但是,采用差频原理的金属探测器在成本低和结构简单方面具有其他形式的金属探测器无法相比的优点,所以很适合于     

基于ATmega16的红外微波双鉴GSM报警器

随着当前人们对家居、小区及企业等防盗防入侵需求的日益提高,安防报警系统得到广泛应用。超声波探测器、热释电红外探测器、微波探测器等这些单一技术的报警探测器都会受到环境干扰而影响探测性能,导致增加了误报率。本文介绍的热释电红外微波复合的探测器把微波和红外感应探测技术运用在一体,相互弥补了这两种感应探测技术的不足,提高了实际探测的可信度并减少了误报率。现今,手机已经成为人们随身携带的通讯工具,基于此,本项目设计了一种应用热释电红外微波复合的探测器和应用GSM模块与手机通信的基于ATmega16的低成本高效安防报警系统。     

基于频域分析的金属探测器设计与实现

金属探测器在大中型连续生产线上得到了越来越广泛的应用，但是传统的金属探测方法存在抗干扰能力差、容易产生误动作的缺点。本文提出了一种基于频域分析的金属探测方法，详细说明了系统的硬件组成、软件结构。试验结果表明：采用该方法设计的金属探测器在满足灵敏度的基础上大大降低了误动作率。     

基于PSD的高精度太阳敏感器电子学系统设计

针对目前国内太阳观测成像仪器稳像系统的需要,提出了一种基于位置敏感探测器(PSD)的高精度太阳敏感器电子学系统的设计,有针对性地提出了提高灵敏度的设计方案和降低系统噪声的具体措施.该系统噪声水平低于4 nA,在工作范围中心区域具备了0.3"的高分辨能力,可以配合偏摆镜结构组成稳像系统,服务于夸父和SPORT计划等具有高分辨率成像需求的太阳成像仪器.     

Design and experiment of an electromagnetic levitation system for a micro mirror

In this paper, the design and characterization of a contactless electromagnetic levitation and electrostatic driven microsystem is presented, which has applications for example for large scale angle rotation micro mirrors. The proposed design can levitate a fabricated aluminum micro rotor which can incorporate a mirror and control it to rotate around the vertical axis within the range of ± 180°, which enlarges the scanning angle dramatically compared with conventional torsion micro mirrors. The rotation angle of the micro rotor is detected by the change of capacitance and controlled by the electrostatic force produced by variable capacitors. The levitation of the micro rotor is realized by utilizing electromagnetic inductions. The rotation is achieved through electrostatic forces generated by a digital controller. The hybrid system design for a micro rotor, combining magnetic and electrostatic forces is introduced. The digital control strategy is based on a PID controller with bias voltage. The detection interface circuit, which is based on frequency multiplexing, is also presented in this paper. It has been experimentally shown that the proposed design can levitate a 1.65 mm radius and 8 µm thickness aluminum micro rotor to 100 µm height with 20 MHz frequency and 0.5A p-p input current. Square and slope wave input experiments were carried out. The experimental results show that the control principal is in good agreement with the simulation models and this applies as well to the time-response performance and stability.

     

某静止卫星海洋辐射计指向镜的操控软件设计

静止卫星海洋成像辐射计是测量海洋目标辐射特性的被动式遥感器。为了使静止卫星探测器达到对探测区域的全覆盖,需要系统计算机处理器驱动控制精密机械转台带动光学指向镜规律运转。文章利用Visual C++开发工具设计一款成像辐射计指向镜的操控软件,通过串口通讯驱动控制指向镜,使得海洋成像辐射计依靠二维指向镜做东西与南北方向的运动指向,实现覆盖区域的调整和观测。在设计中调用了PI公司六轴转台的库函数,运用多线程技术,控制基于PI转台的指向镜巡扫模式可调、运动速度可调。通过软件的增量化设计和测试,结合整机在海上塔台对水体光谱连续采集的外场试验,验证了该软件的设计实现达到海洋辐射计指向镜精密控制的目标,有效提高了地面光学测试和数据处理的工作效率。     

Design,fabrication and vacuum operation characteristics of two-dimensional comb-drive micro-scanner

We present design, fabrication, and characteristics of two-dimensional micro-machined comb-drive scanner to operate in vacuum. The scanner can be actuated in two orthogonal axes using the slanted electrostatic comb-drive and silicon conductive V-shaped torsion hinges fabricated from a silicon-on-insulator wafer. The resonant frequencies of the inner mirror and the gimbal frame are 40 kHz and 162 Hz, respectively. The resonant frequency ratio is 247. The optical scanning angles for the inner mirror and the gimbal frame are 11.5° and 14° at the operation voltages of 12 and 10 V in 1 Pa vacuum, respectively. These driving voltages are smaller by the factors of about 21 and 3 than those in atmosphere, respectively. The dependence of quality factor on pressure for the inner mirror and the gimbal frame is also experimentally investigated and compared with the theoretical calculation based on air-friction models.     

Micro-mirror laser scanner combined with a varifocal mirror

A laser beam scanning system consisting of a scanning micro-mirror and a varifocal micro-mirror is fabricated for laser beam sensing with variable beam diameter. The scanning micro-mirror is operated under the resonant oscillation condition with an electrostatic comb-drive actuator. The varifocal micro-mirror is driven by a bending moment generated at the circumference of mirror with a parallel-palate electrostatic actuator. The scanning micro-mirror and the varifocal mirror are fabricated on a silicon on insulator wafer. The rotational angle of 9° at 766 Hz is obtained at the voltage of 300 V. The spot size of the laser beam is adjusted from 0.5 to 3.5 cm at the distance of 43 m by changing varifocal voltage. The proposed scanning system can be useful for several sensing techniques.     

A water-immersible 2-axis scanning mirror microsystem for ultrasound andha photoacoustic microscopic imaging applications

Fast scanning is highly desired for both ultrasound and photoacoustic microscopic imaging, whereas the liquid environment required for acoustic propagation limits the usage of traditional microelectromechanical systems (MEMS) scanning mirrors. Here, a new water-immersible scanning mirror microsystem has been designed, fabricated and tested. To achieve reliable underwater scanning, flexible polymer torsion hinges fabricated by laser micromachining were used to support the reflective silicon mirror plate. Two efficient electromagnetic microactuators consisting of compact RF choke inductors and high-strength neodymium magnet disc were constructed to drive the silicon mirror plate around a fast axis and a slow axis. The performance of this water-immersible scanning mirror microsystem in both air and water were tested using the laser tracing method. For the fast axis, the resonance frequency reached 224 Hz in air and 164 Hz in water, respectively. The scanning angles in both air and water under ±16 V DC driving were ±12°. The scanning angles in air and water under ±10 V AC driving (at the resonance frequencies) were ±13.6° and ±10°. For the slow axis, the resonance frequency reached 55 Hz in air and 38 Hz in water, respectively. The scanning angles in both air and water under ±10 V DC driving were ±6.5°. The scanning angles in air and water under ±10 V AC driving (at the resonance frequencies) were ±8.5° and ±6°. The feasibility of using such a water-immersible scanning mirror microsystem for scanning ultrasound microscopic imaging has been demonstrated with a 25-MHz ultrasound pulse/echo system and a target consisting of three optical fibers.     

Wide‐angle scanning circular polarization phased array based on polarization rotation technology

A wide‐beam circular polarization (CP) antenna and a wide‐angle scanning phased array based on novel polarization rotation reflective surface (PRRS) are proposed. The CP wide‐beam pattern is obtained by the combination of the radiation wave from the patch antenna and the orthogonal reflected wave from the PRRS with a 90° phase difference. The proposed CP wide‐beam antenna obtains the patterns with the 3‐dB beamwidth more than 136° and the axial ratio (AR) beamwidth more than 132° in the xoz‐plane. Furthermore, an eight‐element phased array based on the wide‐beam CP antenna element is also developed. The measured results show that the main beam of the array can scan from ?65° to 65° with a gain fluctuation less than 3 dB and the ARs at every scanning angle less than 3 dB.     

High gain substrate integrated waveguide beam scanning antenna with sub‐array elements

A method to enhance the gain of substrate integrated waveguide (SIW) beam scanning antenna is proposed in this article. 2 × 2 SIW cavity‐backed sub‐arrays are employed in array design. The antenna is constructed on two layers. The top layer places four SIW cavity‐backed sub‐arrays as radiating elements and the bottom layer is an SIW transmission line to feed the sub‐arrays. Beam scanning feature can be obtained due to the frequency dispersion. Moreover, through separating radiators to the other layer and using 2 × 2 SIW cavity‐backed sub‐arrays as radiating parts, the antenna gain is improved significantly. For a linear array, 4.1 to 6.8 dB gain enhancement is achieved compared to a conventional SIW beam scanning antenna with the same length. Then, the linear array is expanded to form a planar array for further gain improvement. A 64‐element planar beam scanning array is designed, fabricated, and tested. Experimental results show that the proposed planar array has a bandwidth from 18.5 GHz to 21. 5 GHz with beam scanning angle from ?5° to 11.5° and gain in the range of 20.5 to 21.8 dBi. The proposed high gain beam scanning antennas have potential applications in radar detection and imaging.     

高精度微波引导设备角度数据检测系统设计与实现

针对当前某高精度微波引导设备的角度制导性能精准检测难度大的问题,基于ARM+DSP+FPGA的总体架构,研究并搭建了高精度角度数据检测系统的硬件电路结构,基于C/C++、VHDL和Verilog开发了角度数据测试软硬件程序,实现了对微波引导设备空间角度、数据信号的接收、处理、解算和测量;并进行试验验证,结果表明该系统实现了设计功能、达到了指标要求,对高精度微波引导设备角度测量方位角优于0.16°,仰角优于0.18°,数据字与设备预置信息一致,满足高精度角度、数据的检测要求,对有效提高该微波引导设备的可靠性具有重要意义。     

Valve controlled fluorescence detection system for remote sensing applications

We demonstrate a microfluidics-based fluorescence detection device where the filters, source, detector, and electronically controlled valves are embedded into a Polydimethylsiloxane (PDMS)-based microfluidic chip. The device reported here has been specifically designed for chlorophyll a fluorescence sensing in autonomous systems, such as oceanic applications. In contrast to a monolithic approach, the modular approach made the fabrication of this device simpler and cheaper. For fluorescence detection, an InGaN/GaN LED is used as the excitation source to specifically excite chlorophyll a; a metal-dielectric Fabry?CPerot filter was used to extinguish out-of-band excitation. A simple Si photodiode is used as detector and provided with a thermally evaporated CdS emission filter to block the excitation source. This filter combination provides an excellent solution to the difficult problem of combining high-rejection excitation and emission filters in an integrated thin-film format. Furthermore, the metal-dielectric filter provides a much broader angular response than a comparable multilayer Bragg mirror, which is a key advantage in the integrated format. We use a novel paraffin wax-based valve design affords low power single-use actuation, between 0.5 and 1 J per actuation and withstands 0.6 bar differential pressure, which provides better performance than its previously reported counterparts. The remote valve-controlled operation of the fluorescence detection system is demonstrated, illustrating the measurement of a chlorophyll a solution, with a detection limit of 340 ??M and subsequent valve-controlled flushing of the measurement reservoir.     

基于双焦点设计的平面波束扫描透镜天线研究

为了提升平面透镜天线的扫描性能,以实现波束扫描或多波束应用,首先研究设计了单焦点平面透镜天线,针对单焦点平面透镜天线在大角度扫描时增益降低太快的问题,引入了反射阵和传统介质透镜的双焦点设计方法。基于阵列天线合成理论,计算了双焦点透镜天线的辐射特性。采用多层金属孔阵列单元,建模了平面透镜天线模型,仿真对比了单焦点透镜和双焦点透镜天线的扫描辐射特性。结果表明,在扫描范围（0°-27°）内,双焦点透镜天线的最低增益相对于单焦点透镜天线有明显提升,而且大角度扫描方向图形状也有改善,证明了双焦点的设计方法有效提升了平面透镜的扫描性能。