一种DC～10GHz的低附加相移高衰减精度的开关型衰减器

本文设计了一种DC～10GHz的带有低附加相移以及高衰减精度的6位开关型衰减器。分析了三种传统的开关型的T型、简化T型以及∏型衰减器的拓扑结构^[1],通过在∏型衰减器的结构中采用电感和电容补偿技术,实现在超宽带范围内的低附加相移^[2]。该基于55-nm CMOS工艺的6位衰减器,芯片核心版图面积为0.05mm²,仿真结果表明,该衰减器在DC～10GHz频段范围内的插入损耗为3dB～4.3dB,64态的回波损耗均小于10.6dB,衰减误差的均方根值小于0.18dB,64态的衰减附加相移小于2.5度,衰减器在5GHz时处于参考态下的1dB压缩点对应的输入功率为7.7dBm。     

一种晶圆级封装的MEMS数控衰减器

设计实现了一种晶圆级封装的三位MEMS数控衰减器，工作频段DC～15 GHz，衰减范围0～35 dB，步进5 dB。衰减器采用MEMS工艺实现，信号传输采用共面波导（CPW）结构，6个直接接触式悬臂梁MEMS开关对称放置实现不同衰减量的切换，每个开关带有三个触点，电阻网络采用T型结构，整个衰减器实现晶圆级封装。测试结果显示，DC～15 GHz频段内实现了8个衰减态，衰减器插入损耗小于1.7 dB，回波损耗小于-15 dB，衰减平坦度小于±5%，功耗几乎为零。芯片尺寸为2.7 mm×2.7 mm×0.8 mm。     

一种7~13 GHz低插损6位数字衰减器

设计了一种基于0.25 μm GaAs p-HEMT工艺的低插损6位数字衰减器。采用Pi型衰减结构与T型衰减结构级联的方式,实现低插入损耗和高衰减精度。采用相移补偿电路减小附加相移,采用幅度补偿电路提高衰减精度。仿真结果表明,在7~13 GHz范围内,该数字衰减器的RMS幅度误差小于0.5 dB,插入损耗小于5.6 dB,10 GHz时1 dB压缩点的输入功率约为29 dBm,附加相移为-7°~+6.5°,输入输出回波损耗小于-11 dB。芯片尺寸为2.50 mm×0.63 mm。     

一种高频超宽带低插损大衰减范围CMOS数字步进衰减器

设计并实现了一种基于65 nm CMOS工艺的低插入损耗大衰减范围的高频超宽带数字步进衰减器。采用桥T型和π型衰减网络的开关内嵌式衰减结构,该结构具有端口匹配好、衰减精度高的特点;采用恒定负压偏置设计,减小了插入损耗,提高了高频超宽带性能;采用高匹配度的衰减位级联设计,实现了大衰减范围下的高精度衰减。经测试,在10 MHz~30 GHz频带范围内最大衰减量为31.5 dB,衰减步进为0.5 dB,参考态插入损耗<3.5 dB,衰减误差均方根值<0.45 dB。芯片总面积为2.30×1.20 mm^(2)。     

24~30 GHz高精度低附加相移数控衰减器

基于0.18 μm CMOS工艺,设计并实现了一种5位高精度低附加相移数控衰减器。该衰减器的衰减动态范围为15.5 dB,步进为0.5 dB。采用了T型衰减结构和SPDT型衰减结构的衰减网络。采用了悬浮栅和悬浮衬底,提高了衰减精度,减小了插入损耗。采用了相位补偿网络,有效降低了衰减器的附加相移。测试结果表明,在24~30 GHz频带范围内,衰减步进为0.5 dB,插入损耗小于8 dB,衰减误差均方根(RMS)小于0.45 dB,附加相移小于±5°。芯片尺寸为1.2 mm×0.3 mm。     

Q波段双通道幅度控制多功能芯片

设计了一款Q波段的双通道多功能单片电路,其内部集成了威尔金森功分器、六位0.5 dB步进数控衰减器和单刀双掷开关。在设计过程中,开关单元电路采用三级并联结构,有效降低电路插入损耗,提高隔离度;数控衰减器单元采用多节并联T型结构,改善高频段插入损耗和衰减精确度指标。通过以上设计方法,该单片电路在40~50 GHz插入损耗为10 dB,隔离度为26 dB;能够实现幅度控制步进0.5 dB,最大衰减量31.5 dB。     

一种采用砷化镓pHEMT工艺的超宽带DC-40GHz 4位单片数字衰减器

介绍了一种超宽带DC-40GHz的4位单片数字衰减器。该衰减器采用0.25μm砷化镓pHEMT工艺制造。据我所知,这种衰减器是至今国内文献报道中带宽最宽的。它通过采用适当的结构来得到超宽的带宽、低插入损耗以及高衰减精度。该衰减器具有1 dB的衰减步进和15 dB的衰减动态范围,插入损耗在40 GHz时小于5 dB,全衰减态及全频带内的输入输出回波损耗大于12 dB。     

高性能2 ~ 18GHz 超宽带MMIC 6 位数字衰减器

介绍了一种高性能2～18GHz MMIC 6位GaAs PHEMT数字衰减器的设计、制造和测试结果。研制的单片数字衰减器衰减步进为0.5dB;最大衰减范围为31.5dB;参考态插入损耗<5.71dB;所有衰减态的输入、输出电压驻波比<1.8;衰减精度:+2.31dB/-0.51dB;插入相移:+6.28°/-1.53°;64态幅度均方根误差<1.0dB;64态相移均方根误差<1.3°;芯片尺寸:2.89mm×1.22mm×0.1mm。工艺成品率高达85%。     

GaN MMIC六位数字衰减器的设计

基于GaN HEMT工艺成功研制出一款宽带六位数字衰减器,衰减范围为0～31.5 dB.通过研究GaN HEMT开关器件模型及电阻式衰减网络,选取合适的衰减器拓扑,减小了衰减器的插入损耗,提高了衰减精度,缩小了芯片尺寸.测试结果表明,在2～ 18 GHz频带内,该衰减器的插入损耗小于4.8 dB,64态衰减精度均方根误差小于0.6 dB,输入回波损耗小于-13 dB,输出回波损耗小于-12.5 dB,附加相移为-14°～4°.在10 GHz下,其1 dB压缩点输入功率达到34.5 dBm.裸片尺寸为2.30 mm× 1.10 mm.     

一种新颖的4bit和5bit超宽带GaAs单片数字衰减器

介绍了一种新颖的DC～20GHz的4bit和5bit GaAs单片数字衰减器的设计、制造和测试结果.该衰减器的设计采用纵向思维的方法.最终得到的4bit数字衰减器的主要性能指标是:在DC～20GHz频带内,插入损耗≤3.5dB,最大衰减量15dB,衰减步进1dB,衰减平坦度≤0.2dB,衰减精度≤±0.3dB,两端口所有态的电压驻波比≤1.6,相对于参考态,衰减态的插入相移在-10°～5°以内,芯片尺寸1.8mm×1.6mm×0.1mm.5bit数字衰减器的主要性能指标是:在DC～20GHz频带内,插入损耗≤3.8dB,最大衰减量15.5dB,衰减步进0.5dB,衰减平坦度≤0.3dB,衰减精度≤±0.4dB,两端口所有衰减态的电压驻波比≤1.8,相对于参考态,衰减态的插入相移在-14°～2°以内,芯片尺寸2.0mm×1.6mm×0.1mm.     

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