波长和重复频率连续可调的光纤环形激光器

成功地研制了一台波长和频率可调的主动锁模光纤环形激光器。波长可调范围为１５３４～１５６５ｎｍ，频率范围为２．４～２．６ＧＨｚ，产生的光脉冲时间带宽积接近于变换极限。经过改变调制器的直流偏压得到了重复频率为５ＧＨｚ的光脉冲。对实验中的有关原理进行了分析。     

有线电视基础知识讲座第七讲 卫星电视广播接收（上）

有线电视基础知识讲座第七讲卫星电视广播接收（上）　刘修文（湖南攸县有线电视台４１２３００）一、卫星电视信号的传输１．Ｃ波段与Ｋｕ波段目前卫星转发器的工作频段有Ｃ波段与Ｋｕ波段。Ｃ波段的上行频率为（５．８～６．４）ＧＨｚ，下行频率为（３．７～４．２）Ｇ...     

2cm波段耿管电调振荡器

报道了采用部分集成方案研制的Ｋｕ波段变容管调谐耿管振荡器（ＶＣＯ）及两管功率合成器。研制的两只中心频率为１６和１７ＧＨＺ的电调振荡器，其中１６ＧＨＺ的电调带宽大于６４０ＭＨｚ，输出功率大于１１０ｍＷ，功率起伏小于０．６ｄＢ；而１７ＧＨｚ的电调带宽大于２３０ＭＨｚ，输出功率大于１１０ｍＷ，功率起伏小于０．９ｄＢ。两管功率合成器的振荡频率为１７．３ＧＨｚ，输出功率达２５０ｍＷ．     

L波段数字锁相环频率合成器的研究

本文介绍了一种Ｌ波段锁相环频率合成器，频率范围１．１－１．６ＧＨＺ，频率步进为１ＭＨＺ，相位噪声为ε（１０ｋＨｚ）〈－９０ｄＢｃ／Ｈｚ杂散抑制优于５５ｄＢ，输出功率≥０ｄＢｍ。     

8～16GHzGaAs单片宽带分布放大器

报道了８～１６ＧＨｚＧａＡｓ单片宽带分布放大器的设计与制作。单级ＭＭＩＣ电路采用三个栅宽为２８０μｍ的ＧａＡｓＭＥＳＦＥＴ作为有源器件，芯片尺寸为１．１ｍｍ×１．６ｍｍ。在８～１６ＧＨｚ频率范围，用管壳封装的两级级联放大器增益Ｇ＿ａ，为１１．３±１ｄＢ，噪声系数Ｆ＿ｎ＜６ｄＢ，输出功率Ｐ＿（１ｄＢ）＞１６ｄＢｍ。     

主动锁模光纤激光器有理数谐波锁模与重复频率的分频现象

在主动光纤锁模激光器的实验中,我们在较低的调制频率下观察到了有理数谐波锁模的现象。利用不到１．４ＧＨｚ的调制信号,得到了２．８－５．６ＧＨｚ的光脉冲信号。此外,还观察到了重复频率的二分频现象;即输出的光脉冲的重复频率是调制频率的１／２。     

SGS－汤姆逊公司生产5／6×86微处理器

ＳＧＳ－汤姆逊公司生产５／６×８６微处理器意大利－法国ＳＧＳ－汤姆逊微电子公司开始生产５×８６、６×８６微处理器。６×８６于今年一季度销售，５×８６于二季度销售。产品采用８英寸圆片、０．３５μｍ、５层金属化工艺。５×８６时钟频率为１５０ＭＨＺ，６×８...     

一种新型毫米波频率调制器研究

本文给出一种新型毫米波频率调制电路，是将腔稳Ｇｕｎｎ振荡器与变容管调制电路通过反馈调节电路耦合起来形成的，在确需调制频偏的情况下，通过调整环路反馈系数可减少小变容客调制电路对Ｇｕｎｎ振荡器中心频率稳定度的影响，Ｇｕｎｎ振荡器中加一高Ｑ稳频腔，从而可以获得较高的频率稳定度。调制器调制灵敏度为３．５ＭＨｚ／Ｖ，调频线性度估于２％，中心频率稳定度６．５ｐｐｍ／℃（－２０－５０℃），输出功率大于１７ｄＢｍ     

2～18GHz GaAs单片超宽带放大器

介绍了２￣１８ＧＨｚ ＧａＡｓ微波低噪声宽带单片放大器设计原理及主要研究工作，给出了主要研究结果：在２￣１８ＧＨｚ频率范围内，管壳封装的两级级联放大器的增益Ｇ＝１３．５￣１８．３ｄＢ，噪声系数Ｆｎ＝４．２￣６．２ｄＢ，输入电压驻波比ＶＳＷＲｉｎ〈２．０，输出电压驻波比ＶＳＷＲｏｕｔ〈２．５。     

超低相位噪声超高速声表面波雷达频率综合器

介绍了一种新型的高性能雷达频率综合器的制作方法，即采用声表面波技术制作高性能的雷达频综器。采用这种方法成功地制造了Ｌ波段、Ｓ波段、Ｃ波段超低相位噪声超高速频率综合器。该类频综输出信号具有极低相位噪声（１．６ＧＨｚ处：单边带相位噪声Ｌｍ（１ｋＨｚ）＝－１２７ｄＢｃ／Ｈｚ；３．４ＧＨｚ处：Ｌｍ（１ｋＨｚ＝－１２２ｄＢｃ／Ｈｚ；６．８ＧＨｚ处：Ｌｍ（１ｋＨｚ）＝－１１６ｄＢｃ（Ｈｚ）、极短的频率切换时间（约１６０ｎｓ）、低杂波电平（Ｌ波段为－７０ｄＢ；Ｓ波段为－６５ｄＢ；Ｃ波段为－６０ｄＢ）、较多频点（５１点）等多项优异性能。同时，该频综通过了各项环境试验的考核，且长期工作性能稳定。     

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