短路针加载三角形微带贴片天线的研究

短路针加载微带贴片天线具有较低的谐振频率,特别适用于低频便携式通信设备(如手机)中.与短路针加载矩形和圆形贴片天线相比,短路针加载三角形贴片天线具有更低的谐振频率.本文基于腔模理论,利用未加载三角形贴片天线的静态模,提出了短路针加载三角形贴片天线的理论分析方法,给出了天线谐振频率、输入阻抗及反射损耗的计算公式.数值计算与实测结果相吻合,表明这种分析方法是有效的.     

并矢格林函数法分析任意方向短路针加载微带贴片天线

短路针加载微带贴片天线在低频应用时仍能保持体积小的特点,具有广泛的应用前景.推导了矩形微带贴片天线中贴片与接地板之间腔体中的并矢格林函数,并将并矢格林函数用于任意方向短路针加载微带贴片天线的分析中,给出了任意方向短路针加载微带贴片天线谐振频率的计算公式.该公式具有一般意义,对于垂直方向短路针加载微带贴片天线所得谐振频率计算公式与文献[1]所给结果完全一致.     

短路针加载微带天线反射损耗的神经网络模型

短路针加载的微带贴片天线具有较低的谐振频率,特别适用于便携式通信设备中.作者采用多层感知器建立了短路针加载圆形贴片天线的神经网络模型,把短路针位置作为输入样本,天线的反射损耗S11参数作为输出样本,采用BP算法对多层感知器进行训练.当多层感知器训练完成,在学习范围内将短路针位置输入到多层感知器,从输出端立即得到准确的S11参数.     

电调微带贴片天线CAD

研究了探讨针馈电变容管加载的微带贴片天线的电特性,结果表明,在以未加载微带贴片天线的谐振频率2．2GHz为中心,可获得50％的有效阻抗带宽,我们用最简单的传输线模型估算谐振频率,实难结果与预测相当符合。     

基于数据传输的小型天线系统研究

针对一个圆环形微带贴片天线构成的天线系统,出于天线尺寸小型化的要求,通过适当地加入短路针可以使得该天线在较低的频率点处出现谐振峰。仿真结果表明,短路针孔径的大小以及加载的位置会直接影响天线的谐振频率。首先基于HFSS软件设计出天线系统的模型,找到符合要求的天线系统的S参数后将其导成S2P格式文件,并总结出短路针的位置及尺寸对于天线工作在低频处的影响,最后应用ADS软件加入脉冲信号源验证天线系统的传输特性。     

底馈矩形,圆形微带贴片天线的谐振频率和输入阻抗的CAD模型

本文以微带贴片天线的腔模理论为基础，建立了底馈矩形，圆形贴片天线谐振频率和输入阻抗的ＣＡＤ模型，并将所得的结果同有关文献的实测和理论结果进行了比较，结果表明，我们的计算结果与实测结果吻合得较好。     

高温超导微带天线的谐振特性研究

传输线模型是分析微带天线的一种最简单的方法,但其未将导体的特性参数考虑到天线的分析中去,针对这一缺点,为研究超导体的表面阻抗对高温超导微带天线输入阻抗和谐振频率的影响,把导体特性对天线的影响看作一种微扰来处理,对传统的传输线模型进行了修正,并通过与谱域矩量法相比较,验证了修正后方法的有效性.进而利用修正后的方法计算分析了高温超导矩形微带贴片天线的输入阻抗和谐振频率,给出了关于高温超导微带天线输入阻抗和谐振频率的若干结论.     

矩形微带贴片天线的谐振频率

本文采用有限元法对有短路销钉的可调频薄基片矩形贴片微带天线的谐振频率进行计算,其计算结果与实验结果相当一致,该方法原则上适合于多个短路销钉置于任意位置的情形,可能是处理带短路销钉微带贴片天线的最有效的方法。     

利用接地板开槽减缩微带贴片天线的RCS

接地板开槽可以改变微带天线的辐射特性及阻抗特性,在微带贴片天线的频带展宽中已有所应用。该文给出了微带贴片天线散射特性的矩量法求解过程,并分析了接地板开槽对天线雷达截面(RCS)的影响。与短路针加载相结合,给出了一种接地板开槽形式。结果表明,据此设计的微带贴片天线在较宽频带内实现了RCS的减缩,同时天线的辐射性能保持良好,对天线的隐身有一定的借鉴作用。     

矩形微带贴片天线的简化多端口网络模型

提出了矩形微带贴片天线的简化多端口网络模型，并运用该模型和二维平面电路的分析方法计算了一矩形微带贴片天线的输入阻抗，所得结果与一些文献的计算结果和实验结果相一致，证明了所用方法是有效的。     

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.     

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

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.     

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.