基于微波谐振腔的葡萄糖溶液浓度测量系统

根据微波谐振腔的谐振频率随腔内溶液的介电常数的变化而发生偏移的特性,本文设计了基于微波谐振腔的葡萄糖溶液浓度测量系统,包括谐振腔测量模块、谐振频率跟踪模块和等精度频率测量模块,可实现对溶液浓度的实时测量。谐振频率跟踪模块利用单片机控制压控振荡器(Voltage Controlled Oscillator,VCO)的输出频率,使VCO的输出频率与谐振频率实时保持一致,实现了谐振频率的自动跟踪。等精度频率测量模块在标准频率为50 MHz时,误差达到2×10-8,浓度测量分辨率达到0.01mmol/kg。     

无源谐振腔的谐振频率偏移效应

无源谐振腔的有效谐振频率（被测得谐振频率）偏移作为参考的基模谐振频率的效应是谐振腔中存在的高阶横模所引起的。由光探测器光接收孔径的有限性或表面的不均匀性而导致各阶横模的空间不正交性，是引起谐振频率偏移效应的主要原因。对此作了详细研究，并对计算结果进行了讨论，总结出谐振频率偏移与谐振腔各参量的相互关系，从而提出减小这种效应的有效措施。     

W 波段回旋管谐振腔特性参数测量方法的研究*

W 波段回旋振荡管是一种重要的高功率毫米波源,它通常采用圆柱开放式谐振腔作为其高频结构。 谐振腔所具有的特性参数,如谐振频率和品质因数影响了整管的性能。在W 波段,特性参数对于尺寸的变化特别敏 感,因此,有必要对加工好的开放式谐振腔的特性参数进行测量。利用直接耦合法实现了对5 组开放式谐振腔谐振 频率和品质因数的无损检测,实验结果验证了该方法的可行性与有效性。同时,分析了加工误差对谐振腔性能造成 的影响,结果表明,当开放式谐振腔渐变角度的加工误差达到7%以上时,谐振频率将偏移0.2GHz。     

谐振腔参量的扫频比较法测量

概述比较法扫频测量谐振腔参量是建立在可调参考腔与测试比较腔的基础上,通过x—y记录仪绘出闭合回线,腔参量(f_oQ_L及β)便可很方便的从曲线中求得,每一个闭合回线就是腔参量的一个独立计算,通过绘制大量的回线轨迹,再借助于计算机便能很快地完成腔参量的计算。尤其是谐振腔的谐振频率测量,利用示波器可以迅速地完成测量,其测量精确度是极高的。对于大批量的谐振腔的谐振频率测试,具有快速、简单、精确的特点,尤宜适用于一般生产上磁控管谐振频率的频率冷测,是一种多快好省的测量方法。     

扫频测量谐振腔参量

本文介绍了扫频比较法测量谐振参量,可以取得较高的精度。根据输入反射系数的平方|S|~2和变换器增益的平方|S|~2,在显示系统描绘出轨迹曲线,提供计算谐振腔的谐振频子,负载品质因素和耦合系数等参量。具有快速、简单的特点,适合于大批量谐振腔测量。     

带金属柱矩形贴片天线的谐振频率

首次采用有限元与谐振腔模型结构的混合有限元方法对有金属方柱的薄基片矩形贴片天线的谐振频率进行了数值计算和实验分析，谐振频率的计算结果与实验结果符合很好。     

扫频测量的频率偏移与动态带宽

本文通过理论分析揭示并探讨了滤波网络扫频测量时幅频特性的频率偏移和动态带宽现象的成因.并通过数字仿真对理论分析进行了验证,说明和探究了扫频速度与频率偏移和动态带宽展宽的程度之间的关系.该研究有助于扫频测量偏差的分析和特殊通信滤波器的设计.     

谐振腔光纤陀螺信号检测方法的研究

谐振腔光纤陀螺(R—FOG)是利用光学Sagnac效应实现对转动检测的一种高精度的惯性传感器件。在谐振腔光纤陀螺系统中，信号检测系统占有非常重要的地位，其检测精度的大小直接影响陀螺的分辨率。光纤环形谐振腔是谐振腔光纤陀螺的核心敏感部件。采用两种频率的锯齿波组合调制，考虑激光器有限光谱线宽条件下，采用洛仑兹线型描写光纤环形谐振腔的输出光强表达式。针对输出光强与谐振频率偏差在靠近谐振点附近的近似线性关系，利用多次反馈频率操作来依次跟踪谐振腔光纤陀螺顺时针和逆时针光束的谐振点，从而避免了谐振频率偏差复杂的求根算法。仿真结果表明，多次反馈频率操作，可以较快地锁定到谐振点。     

陶瓷谐振器特性参数测试方法研究

分析了现有的陶瓷谐振片测试方法和存在的不足,提出采用扫频法测量陶瓷谐振器串联谐振频率、并联谐振频率、谐振阻抗等参数。测试系统主要由扫频信号发生器、放大器、分压电路、检波电路、A／D转换器等几部分组成。扫频信号由LAI200任意波形发生卡产生。扫频法不仅能够测量陶瓷谐振器的多个参数,而且可以直观地显示出谐振器的频率特性曲线。该测试方法应用到陶瓷谐振器自动化分拣装置上,试验结果表明,相对于谐振频率法可以更全面地控制产品质量。     

加载小型天线的谐振腔特性分析及应用研究

提出了一种测量小型天线的方法,以适应对数量极为庞大的终端天线产品特性的逐一检测.理论分析和实验验证均表明:谐振腔内放入双频天线时,会出现三个谐振频率,其一为加载天线后的腔体的谐振频率,另外两个是受外加激励由天线产生的辐射场.前者携带有天线几何结构及其构成材料的信息,后者含有天线辐射特性方面的信息.据此,建立了一套可对批量天线产品性能进行检测的谐振腔系统,该系统还可对其它小体积样品的物理特性进行测量,同时使谐振腔的应用由对一般材料特性的测量扩展到了对有辐射特性器件的测试.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.