大型双锥椭圆笼形天线关键参数的影响分析

基于同轴线馈电的并行时域有限差分(finite-difference time-domain,FDTD)方法,研究分析了双指数脉冲源激励的位于地面上的大型双锥椭圆笼形天线的辐射场,给出了天线的椭圆形笼半径、双锥半角、架高及圆心间距等几个关键参数对该天线辐射场的影响.研究表明:椭圆形笼的半径从3.0 m增加到4.5 m时...     

宽带毫米波全向天线研究

介绍了一种宽带毫米波不对称双锥喇叭全向天线。采用脊波导－同轴线过渡结构馈电网络，既解决了毫米波段双锥喇叭的电问题，又满足了天线输入端口必须为波导形式的实际工程要求。测试结果表明在２６－４０ＧＨｚ频带内，天线的全方向性和输入皮比均满足设计要求。     

集成光波导强电场传感器天线电极仿真分析

提出一种用于强电场测量的集成光波导电场传感器天线电极设计方案。给出了传感器等效电路,计算分析了天线、电极的各个参数对传感器半波电场的影响。结果表明:当传感器电极长度、天线长度由4mm减少到0.5mm时,传感器半波电场由230kV/m分别增加到2 400kV/m和1 100kV/m,提高了943.5%和378.3%;当电极间距、电极宽度由20μm增加到200μm时,传感器半波电场由400kV/m分别增加为2 300kV/m和730kV/m,提高了475.0%和82.5%;当天线底部宽度由50μm增加到600μm时,传感器半波电场由460kV/m减小到242kV/m,减小了47.4%。因此,合理设计传感器电极、天线尺寸可使其半波电场达到几百kV/m至几千kV/m,使它能够应用于强电场测量领域。     

基于新型矩形同轴馈电网络的微带天线阵研究

研究了一种新型的C波段微带天线阵,他采用矩形同轴线(RCL)结构构成的集成化低损耗馈电网络馈电,有效降低了馈电网络损耗,提高了微带天线阵增益。首先分析了矩形同轴线相关理论,并对矩形同轴线馈电网络和微带天线子阵的基本原理和设计方法,分别运用HFSS和CST进行了仿真设计。仿真和实测结果表明,该馈电网络具有损耗低、稳定性好等优点,实测结果与仿真吻合。     

一种基于MEMS芯片的新型地面大气电场传感器

该文基于MEMS电场敏感芯片,研制出了一种新型的地面大气电场传感器,解决了现有场磨式电场仪易磨损、功耗大、故障率高等问题。敏感芯片采用SOIMUMPS加工工艺制备,其芯片面积仅为5.5 mm5.5 mm。该文提出了传感器敏感芯片的弱信号检测方法,设计出了满足环境适应性的传感器整体结构方案,并建立了传感器的灵敏度分析模型。对电场传感器进行测试,测量范围为-50 kV/m~50 kV/m,总不确定度为0.67%,分辨力达到10 V/m,功耗仅为0.62 W。外场试验结果表明,MEMS地面大气电场传感器在晴天和雷暴天的电场探测结果,与Campbell公司场磨式电场仪探测结果都有较好的一致性,说明该传感器能满足预测雷暴要求,实现雷电监测和预警功能。     

二元喇叭天线阵列的互耦研究

通过同轴线给天线馈电的方式,采用细导线FDTD方法模拟同轴线,研究了同轴传输线口径处内、外场之间的耦合,并分析了二元TEM喇叭天线阵的耦合问题,通过对单一喇叭进行馈电计算了天线阵单元的自阻抗和互阻抗.结果表明.在所考虑的频段内自阻抗和互阻抗不随频率的变化而变化,具有很好的宽带性能.     

新型舰载超短波宽带天线

采用双锥组合变形、多端馈电和套筒结构匹配等技术设计了一类用于舰载超短波通信的小型宽带天线.通过反复实验调整和优化,给出了天线的设计形式和尺寸.在15倍频以上的频带范围内,天线的VSWR基本低于2.5,辐射特性为水平面全向、俯仰面侧射,而尺寸远小于同样用途的传统笼锥类天线,因而具有较大的应用价值.     

光纤传输脉冲电场传感器的时域校准

介绍了一组适用于0.1 V/m～25 kV/m动态范围内电磁脉冲电场传感器时域校准的标准场产生装置,对一套采用光纤传输的脉冲电场传感器的性能进行了测试,获得了传感器的电压/场强灵敏度系数、脉冲响应特性和稳定性.并通过实验室间比对进一步评估了该套测量装置的性能.     

300 kV激光触发多级真空开关结构设计

激光触发真空开关具有优异的工作性能，在脉冲功率系统具有很好的应用前景。本文以300 kV为设计指标，对激光触发多级真空开关进行结构设计与优化。首先进行激光触发间隙的结构设计，靶材由KCl和Ti混合制成，采用铜铬合金纵磁电极；其次进行自击穿间隙的结构设计，自击穿间隙采用平板不锈钢电极，结合不同圆角半径下的电场仿真结果，确定电极外侧圆角半径为5 mm,内侧圆角半径为3.5 mm;通过对绝缘支柱闪络机理的分析，使用带伞裙的圆柱形尼龙绝缘支柱并采用电极嵌入绝缘支柱降低三交界面电场；最后根据开关的欠压比、过压倍数和稳定性，确定自击穿间隙采用三个3.7 mm长的真空短间隙，各间隙承担电压为180、40、40、40 kV。     

单极天线和偶极子天线辐射特性数值计算*

采用时域有限差分法(FDTD)在柱坐标系下对同轴线馈电单极天线辐射特性进行数值计算,推导了二维扩展柱坐标下修正的Maxwell方程,应用辅助微分方程FDTD法对修正的Maxwell方程进行了差分离散,以TM波在自由空间中的传播为例,仿真了电磁波在自由空间中传播过程并分析了坐标伸缩完全匹配层的性能,建立了单极同轴线馈电天线仿真模型,仿真分析了同轴线馈电单极天线的近场、远场及阻抗特性。在三维直角坐标系下建立了偶极子天线仿真空间模型,数值计算了偶极子天线不同切面的远场方向图,仿真结果与客观实际相同,验证了空间模型及相关理论的正确性。     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks