全等效电流积分方程法分析微带天线

提出了一种分析微带天线的新方法——全等效电流积分方程法。根据等效原理，用等效表面电流表示金属导体影响，用等效体极化电流来取代介质结构影响，建立全等效电流积分方程，结合空域矩量法来求解整个微带结构的电流分布。采用该方法可以分析任意结构的微带天线，只需用最简单的自由空间格林函数而无须求解复杂的谱域或空域格林函数，避免了无穷积分或Sommerfeld积分，且在分析中精确考虑了有限尺寸金属接地板的影响。用该方法分析了矩形微带天线，计算结果与其它文献给出的结果一致，证实了该方法的有效性。     

矩形手征微带天线的辐射特性

本文首先建立了有覆盖层的矩形手征微带天线的数学模型，应用谱域导抗法得到了不同区域中的说域并矢格林函数，借助矢量法数据分析了手征介质的本构和几何参数，以及矩形贴片的几何形状等参量对微带天线的谐振频率和方向图的影响程序，发现了一些有趣的现象。     

微带天线全波频域法中的小波应用

本文将小波分析引到微带天线全波频域法的计算中，对矩形微带贴片天线感应电流矩量法的小波计算进行了理论推导。对一矩形微带贴片天线进行了实际计算，并与用脉冲基函数和三角形基函数进行计算得到了结果进行了比较。     

球状分层微带天线并矢格林函数的有效处理

采用提取格林函数渐进项的方法,成功克服了分层介质中球并矢格林函数计算无穷级数收敛慢的缺陷,提取出的级数形式的格林函数用球汉克尔函数的加法定理转换成闭合形式的格林函数,通过化简,使之与自由空间的格林函数有着相同的形式。因此,可采取相同的方式处理格林函数的奇异性,然后,采用以RWG为基函数的矩量法计算了圆形贴片与方形贴片微带天线的输入特性,并与文献结果、FEKO仿真结果比较,验证了方法的有效性和正确性。     

球形分层媒质中并矢格林函数的求解域: 并矢格林函数快速计算*

首先,采用勒让德多项式的加法定理,对PartΙ部分得到的并矢格林函数进行化简,将双级数和形式转换成单级数和形式。然后,将场型格林函数转换成位型格林函数,将九个分量中收敛慢的TM 分量统一合并成公共的标量位函数。接着,利用球贝塞尔函数和汉克尔函数的渐近公式,导出并矢格林函数的渐近函数,以加速格林函数的收敛速度。最后,计算了球面共形微带天线的输入阻抗,与文献计算结果吻合,说明了处理的正确性和有效性。     

左手分层媒质微带天线的辐射特性研究

在推导左手分层媒质谱域并矢格林函数的基础上,分析得出了左手媒质谱域格林函数的慢收敛特性。为了将谱域格林函数转换到空域并对其进行准确的数值计算,根据左手媒质的特性,对传统的离散二级离散复镜像法提出一些改进,计算结果与变形路径的直接积分法吻合较好,验证了改进方法的正确性、精确性。运用此格林函数对一些不同参数的左手媒质微带天线辐射特性进行了全波分析,并得出它们主瓣宽度窄、低仰角等特点。     

准光腔单微带贴片输入阻抗的理论分析

本文利用并矢格林函数获得了准光腔中的电磁场积分方程。利用矩量法导出了被一个轴向电流源激励的单微带贴片腔的输入阻抗的计算公式。利用本方法对矩形微带贴片的输入阻抗进行了讨论。其结果与微带天线很类似。这对设计微带型准光振荡器有重要的参考价值。     

准光腔单微带贴片输入阻抗的理论分析

本文利用并矢格林函数获得了准光腔中的电磁场积分方程。利用矩量法导出了被一个轴向电流源激励的单微带贴片腔的输入阻抗的计算公式。利用本方法对矩形微带贴片的输入阻抗进行了讨论。其结果与微带天线很类似。这对设计微带型准光振荡器有重要的参考价值。     

矩形微带天线的一种快速优化设计方法研究

针对矩形微带天线优化设计主要依赖经验和反复试验的现状,研究提出了一种矩形微带天线的快速优化设计方法。分析了传输线理论对矩形微带天线分析时的准确性,并将传输线理论成功地与改进的量子遗传算法(IQGA)相结合,应用于矩形微带天线的优化设计之中。利用该方法优化设计了一款矩形微带天线,通过将设计分析的结果与有限元软件HFSS计算结果比较,说明该算法的高效性及准确性。为方便该方法的应用,开发了一款矩形微带天线的快速优化设计软件包。     

介质覆盖矩形微带天线的理论与实验

本文研究了介质覆盖矩形微带天线的特性，精确的谱域全波分析方法被扩展到这类天线的分析中，给出了理论计算公式，探讨了介质覆盖层和对矩形微带天线的驻波比的影响，实验结果证实了理论计算的正确性。     

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.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.