单脉冲雷达多模馈源分析与设计

详细分析了单脉冲雷达四喇叭三模馈源的原理和设计方法,指出馈源模比的变化和口径面相位分布的不一致,都会对馈源的方向图产生影响,考虑这些因素,经过严格推导,得出了这种馈源方向图的完整解析表达式。利用该结果,分析频率和模比对馈源方向图的影响,设计最优的馈源模比,计算出理想的馈源的和差方向图。并进一步对馈源的相位中心进行了分析,给出了频率和喇叭1：7面的相位分布对相位中心的影响结果。这些都会对工程设计具有一定的指导意义。     

双频共面单脉冲天线研制

论述了双频共面单脉冲天线的设计方法。天线口径较小时,馈源的遮挡口径相对较大,这对天线的性能影响很大,选择口径较小的双频馈源是实现双频共面的关键。天线低频段馈源采用4喇叭单脉冲形式,高频段馈源采用单口多模单脉冲喇叭,通过各自的馈电网络实现单脉冲功能。天线采用卡塞格伦形式,通过对天线和馈源的优化设计,可实现天线双频段工作性能,实测结果与计算结果基本吻合。     

单脉冲雷达的波纹波导多模馈源

本文叙述一种用于单脉冲雷达的波纹多模馈源的性能。该馈源用四个方喇叭输出口来激励和模与差模。适当地选择参数能使辐射方向图具有低的交叉极化电平,因而可适应截获目标的极化特性。本文给出了波导不连续性问题的分析结果并讨论了波导模之间相位差的补偿方法。一些初步的实验结果同理论计算相符合。     

一种宽带单脉冲赋形反射面天线设计

文中设计了一个新型的双端口馈电共壁喇叭作单脉冲馈源,通过改变喇叭张角和末端形状,产生可利用的高次模TE₃₀,来改善喇叭的辐射特性。该馈源喇叭耐功率高、结构紧凑、易于加工;在30%的带宽范围内可实现期望的和/差波瓣。给出了赋形反射面天线的初步估计方法,应用迭代优化算法设计了一个赋形反射面天线,并应用快速多极子进行了远区波瓣性能计算,计算结果满足指标要求,该设计方法对工程应用具有借鉴价值。     

6喇叭单脉冲馈源设计

设计了一种6喇叭多模单脉冲馈源,较好地解决了“和差矛盾”,推导了计算公式,分析了口面相差和互耦对初级照射的影响,并把计算结果和实验结果进行了比较。     

双频段、圆极化、单脉冲多模馈源

本文是一单脉冲试验多模馈源的研制小结。叙述了设计思想、设计方法,列出了主要试验结果。论述了圆极化多模馈源产生交叉耦合的原因及其抑制方法。     

天线馈源与捕获天线

确定采用卡塞格伦馈源系统,因为它能较好地解决必须安装在馈源附近的设备带来的复杂性。在原来设计的卡塞格伦馈源中对已试验过的设计略加修改,以满足稳定性的要求。馈源采用基本的四喇叭单脉冲结构,其通讯信道由四个喇叭的和构成。通过在侧壁激励器产生的高次模改变E平面的分布,     

共反射面双频段单脉冲馈源设计

叙述了共反射面双频段单脉冲馈源的一种设计方法，该馈源采用了各自频段的喇叭馈电，实现了双频共面馈电的技术要求。根据馈源的理论方向，计算了天线的理论方向图。     

波纹壁参数变化的波纹喇叭的理论分析

波纹壁参数(内径、等效导纳、及半锥角)按照特定规律变化,可以抑制有害的高次模,或产生适当数量的特定高次模,构成纯模或多模波纹喇叭,以改善喇叭的辐射特性和缩短喇叭的长度。本文导出了两种变参数(连续变化和折线式变化)波纹喇叭的设计公式。文中通过一个实例比较了复合式多模喇叭辐射场的计算值和实测值,其结果是满意的。     

复合式多模喇叭

波纹喇叭与光壁多模喇叭是两种比较理想的高效率馈源。本文进一步研究了波纹与光壁两种系统的模转换,提出了把波纹壁混合模技术与光壁多模技术综合应用于一个喇叭的设想,介绍了使其分别控制不同频区的特性的工程设计方法,成功地研制了尺寸小、性能好、加工方便的双频区复合式多模喇叭。作为改进型双镜天线的馈源,在4/6GHz频段上,使天线的效率达到70％以上(除少数频率外)。显示了综合运用各种混合模与光壁多模技术研制新型高效率馈源的可能性。     

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.     

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.     

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.     

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