由多路负反馈有源滤波电路组成的多频段图示均衡器

本文给出一种用反馈放大器型有源滤波器组成的参量均衡(Parametric EQ)电路,用以构成一个29段图示均衡器,并给出了实用电路、实验数据和测试结果。本电路的优点是各频段的中心频率Q值和增益等参量可以分别独立调节,互不影响。特别适用于频段数较多的专业图示均衡器,对10段以下的民用均衡器同样具有参考价值。     

半模基片集成波导增益均衡器的设计和实现

针对增益均衡器小型化的发展趋势和要求,设计了多子结构单元级联的Ku波段的半模基片集成增益均衡器.谐振子单元与主传输线在三层介质基板上,成空间立体分布,构成七层结构;提出了利用多节微带线枝节进行阻抗匹配的过渡带设计方法,根据坐标变换分析得到HMSIW谐振腔的主模;采用羟基铁填充的吸收柱阵列调节衰减量和Q值,给出了该结构均衡器的设计步骤.与微带均衡器相比,该均衡器提高了Q值,减小了损耗.测试结果表明,该结构保持了和腔体类均衡器相同的性能,同时缩小了体积,实测结果与目标均衡曲线吻合度较好,最大差值为0.6dB.行波管与均衡器联测后,输出增益波动小于±0.4dB.     

三角波信号参数测试仪

提出由三角波信号发生器和三角波信号参数测试仪组成的系统设计.信号发生器以FPGA为控制核心,基于直接数字频率合成原理,产生频率、幅度、占空比连续可调的三角波信号;而三角波信号参数测试仪以等精度法实现了精度为10~(-6)的三角波频率测量:以数字峰值检波的方法实现了幅度测量,其误差小于1%;以多点求均值的方法也降低了求取斜率的误差.该系统设计为实验室产生多参数同时可调的三角波及三角波的精确检潮提供可能.     

基于分类思想的改进粒子群优化算法

针对粒子群算法存在收敛速度慢、收敛精度低且易收敛到局部极值的问题,提出一种基于分类思想的粒子群改进算法。该算法将粒子适度值和适度值均值做差与适度值标准差进行比较,从而将粒子所在区域划分为拒绝域、亲近域、合理域。根据不同区域中粒子的特点选取不同惯性权重和学习因子,使粒子高效地选择自身经验或种群经验,合理增强或减弱粒子全局搜索能力和局部搜索能力。数值实验结果表明,与其他粒子群改进算法相比,新的分类粒子群算法有效加快了粒子的收敛速度,提高了算法的收敛精度,有效改善了算法寻优性能。     

有源R二阶滤波器

本文提出用两个运算放大器和五个电阻组成的有源R二阶滤波器的两种电路。第一种电路具有带通,低通和对称带阻传输特性,第二种电路具有带通、低通和高通传输特性。两种电路的极点参数ω_0,Q和增益均由相应电阻比来确定。两种电路带通传输的中心频率、3dB带宽和中频增益均可分别独立调节。两种网络对全部有源参量和无源参量呈现很低的灵敏度。实验结果与设计值基本符合。     

双模方形谐振腔增益均衡器的设计与实现

针对均衡器小型化、高Q值的应用需求,提出并设计了一个工作在Ku波段的双模方形基片集成波导谐振腔均衡器.设计了两个正交的耦合缝隙,在谐振腔中激励起简并模TE₂₀₁和TE₁₀₂;使用金属柱微扰其中一个模式,实现独立调节该模式的谐振频率,并且频率调节自由度高;研究了薄膜电阻的加载位置,实现独立调节两个模式的衰减量和Q值;分析了双模谐振腔级联后谐振频率偏移量及可调性,给出了双模谐振腔均衡器的分析和设计方法.相比于传统单模谐振腔均衡器,该结构均衡器保持了原有的工作性能,并减少了一半数量的谐振腔,使得结构更加紧凑.测试结果与仿真结果吻合,最大误差0.4dB.     

一种超高频高Q值CMOS带通滤波器设计

介绍了一种基于Nauta跨导一电容积分器的CMOS集成滤波器设计。在滤波器设计过程中,利用改进的Nauta导具有可调增益、高线性度、宽频域特点,使滤波器可工作在UHF频段并有高品质因数Q,仿真结果表明,所设计的滤波器采用Cllarted Semiconductor Manuhcturing（CSM）0．35um CMOS工艺,工作电压为3V,Q值可达到40-100,当中心频率为433MHz,Q值为40时,无杂散动态范围（SFDR）约为61．4dB,并可通过调节电路偏压达到对中心频率ωc和Q的调谐。     

基于TE01δ模的新型Ku波段微带可调均衡器

微带均衡器可调化问题一直是微带均衡器研究的热点,国内报道的几种"可调"微带均衡器在功能和设计上均有明显不足.不能实现真正的加工后灵活可调.为了解决上述问题,文中设计了一种新型的基于TE<,01δ>模的Ku波段微带均衡器.该均衡器达到了在电阻加载平面微带均衡器上引入介质谐振器,通过在介质谐振器上增加频率调节器、耦合调节器,灵活地调整谐振器的频率、Q值及衰减幅度的目的,解决了微带均衡器加工后不可调的难题.     

基于传感中低Q电感的测量

电感是兼有固有电感、分布电容、损耗电阻3个参量的元件,其参数不仅随电压变化,而且又是频率的函数。有些电感Q值极低,测量更为困难,为解决这些问题,提出了具体测量方案及实际应用电路。     

突发信号盲存在性检测的两种算法

本文从频率域和广义频率域研究了复数高斯白噪声信道中突发信号的存在性检测问题,分别提出了基于频率域短时傅氏变换幅度谱熵和基于广义频率域奇异值分解的检测算法,并与时间域的短时能量算法进行了比较.仿真结果表明谱熵法具有较好的鲁棒性,特别是在低信噪比时能够获得较高的检测概率,并且受突发信号调制方式等参数的影响较小.奇异值算法与短时能量法相比更适用于采用QAM调制的突发信号.     

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.     

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.     

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.     

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