一种16位600 MS/s电流舵D/A转换器的设计

基于0.18 μm CMOS工艺,设计了一种16位600 MS/s电流舵D/A转换器。该D/A转换器为1.8 V/3.3 V双电源供电,采用并行输入、差分电流输出的四分段(5+4+3+4)电流舵结构。采用灵敏放大器型锁存器可以精确锁存数据,避免出现误码;由恒定负载产生电路和互补交叉点调整电路组成的同步与开关驱动电路,降低了负载效应引起的谐波失真,同时减小了输出毛刺;低失真电流开关消除了差分开关对共源节点处寄生电容对D/A转换器动态性能的影响。Spectre仿真验证结果表明,当采样频率为625 MHz,输入信号频率为240 MHz时,该D/A转换器的SFDR为78.5 dBc。     

低功耗10位30MS/s流水线A/D转换器

基于0.18μm CMOS混合信号工艺,设计了一个低功耗10位30 MS/s流水线A/D转换器.通过优化各级采样电容和运放(0TA)偏置电流,以及使用动态比较器,大大降低了整体功耗.采用增益自举开关,以减少开关非线性;引入数字校正技术,以提高转换精度.当采样时钟频率为32 MHz、输入信号频率为16 MHz时,信噪失真比(SNDR)为59 Db,无杂散动态范围(SFDR)为71 Db.AD(:核心电路版图面积为0.64 mm2,功耗仅为32 Mw.     

一种抗辐射16位80 MSPS A/D转换器设计

为满足航天电子系统对高速高精度16位A/D转换器的需求,设计了一种流水线型16位80 MSPS A/D转换器,内核采用“3+4+3+3+3+3+3”七级流水线,前端缓冲器用于减小第一级MDAC采样网络回踢信号对A/D转换器线性度的影响。采用环栅器件、N+/P+双环版图等设计加固技术。A/D转换器采用0.18 μm CMOS工艺,工作电源电压为3.3 V和1.8 V,在时钟输入频率为80 MHz和模拟输入频率为36.1 MHz时,ADC的功耗≤1.1 W、信噪比SNR≥73.8 dB、无杂散动态范围SFDR≥88 dBFS。电离总剂量150 krad(Si)辐照后,ADC的信噪比SNR变化量≤0.3 dB、无杂散动态范围SFDR变化量≤1 dB;Bi离子辐照下ADC的电流增加≤4 mA。     

一种14位400MS/S分段型电流舵DAC的设计

基于TSMC O.25μm CMOS工艺,采用分段开关电流结构,设计了一种基于2.5 V电源电压的14位400MS/s D/A转换器.该D/A转换器内置高精度带隙基准源、高速开关驱动电路和改进的Cascode单位电流源电路,以提高性能.D/A转换器的积分非线性(INL)和微分非线性(DNL)均小于0.5 LSB.在400 MHz采样频率、199.8 MHz输出信号频率时,其无杂散动态范围(SFDR)达到85.4 dB.     

一款带8选1MUX的14位2.5GS/s D/A转换器

本文介绍了一款带8选1MUX的14位2.5GS/s D/A转换器。该转换器采用了“5+9”分段PMOS电流舵结构,偏置电路保证PMOS电流源阵列能够在PVT（温度、电源电压、工艺角）变化的条件下获得较大的输出阻抗。高速8to1 mux电路采用了3级结构,采用恰当的数据选择时序,提高了数据合成的可靠性。D/A转换器输入数据的高5位译码器中加入了DEM功能改善了D/A转换器模拟输出的动态性能。本文所述的带8选1MUX功能的14位2.5GS/s D/A转换器内嵌在一款高性能DDS电路中,流片的实测结果显示在时钟2.5GHz下, MUX和D/A转换器工作正常,输出信号在1GHz带宽范围内,SFDR> 40dB。与目前国际上已发表的非模拟重采样结构的D/A转换器（即没有采用“归零”或“四开关”这些模拟重采样结构）相比,本文介绍的D/A转换器具有较高的时钟频率（2.5GHz）和较好的高频SFDR性能(>40dB, up to 1GHz)。     

8通道14位40 MS/s流水线型A/D转换器

实现了一种8通道14位40MS/s流水线型A/D转换器。采用全差分开关电容结构的采样/保持电路,可以很好地抑制来自衬底的共模噪声,降低各种非线性因素引入的失真;利用"4+4+4×1.5+4"多级流水线结构的核心模数转换器单元,实现了转换器速度、精度、功耗以及版图面积的优化设计;基于电荷泵锁相环产生的1倍频和7倍频两组相位同步时钟信号,分别用于多级流水线采样保持和并行数据的并串转换;通过具有共模反馈的双电流源LVDS驱动器,实现了与外部560MB/s的高频数据接口。该电路采用0.18μm CMOS工艺,在时钟频率为40MHz,模拟输入频率为10MHz的条件下,实现了功耗≤1.2W,信噪比≥71dB,通道隔离度≥80dB。     

一种用于高速高精度A/D转换器的自举采样电路

介绍了一种新型的CMOS自举采样电路。该电路适用于12位100 MHz采样频率的A/D转换器。采用P型栅压自举开关补偿技术,可以有效地克服采样管导通电阻变化引入的非线性失真,提高采样精度。仿真结果表明,采样时钟频率为100 MHz时,输入10 MHz信号,可得信噪失真比(SNDR)为102 dB,无杂散动态范围(SFDR)为103 dB。信号频率达到采样频率时,仍有超过85 dB的SNDR和87 dB的SFDR,满足高速高精度流水线A/D转换器对采样开关线性度和输入带宽的要求。电路采用SMIC 0.18μm CMOS数模混合工艺库实现,电源电压为1.8 V。     

一种10位10 MS/s自补偿SAR A/D转换器

基于SMIC 0.18 μm CMOS工艺,设计了一种10位自补偿逐次逼近(SAR)A/D转换器芯片。采用5+5分段式结构,将电容阵列分成高5位和低5位;采用额外添加补偿电容的方法,对电容阵列进行补偿,以提高电容之间的匹配。采用线性开关,以提高采样速率,降低功耗。版图布局中,使用了一种匹配性能较好的电容阵列,以提高整体芯片的对称性,降低寄生参数的影响。在输入信号频率为0.956 2 MHz,时钟频率为125 MHz的条件下进行后仿真,该A/D转换器的信号噪声失真比(SNDR)为61.230 8 dB,无杂散动态范围(SFDR)达到75.220 4 dB,有效位数(ENOB)达到9.87位。     

8 bit 800 Msps高速采样保持电路的设计

为适应目前无线通信领域对高速A/D转换器的要求,采用在Cadence Spectre环境下进行仿真验证的方法,对高速A/D前端采样保持电路进行了研究.提出的高速采样保持电路(SH)采用SiGe BiCMOS工艺设计,该工艺提供了0.35 μm的CMOS和46 GHz TT的SiGe HBT.基于BiCMOS开关射极跟随器(SEF)的SH,旨在比二极管桥SH消耗更少的电流和面积.在SH核心,电源电压3.3 V,功耗44 mW.在相干采样模式下,时钟频率为800 MHz时,其无杂波动态范围(SFDR)为-52.8 dB,总谐波失真(THD)为-50.4 dB,满足8 bit精度要求.结果显示设计的电路可以用于中精度、高速A/D转换器.     

一种12位400 MHz电流开关型D/A转换器的设计

基于TSMC 0.25μm工艺、采用电流开关结构,设计了一个3.3 V 12位400 M采样率的D/A转换器。在电路中,设计了一种新的电压限幅结构,从而使其具有较好的动态性能。该D/A转换器在1 MHz输入信号下,无杂散动态范围(SFDR)达到83.75 dB;在12.5 MHz输入信号下,可获得70 dB的SFDR;在不同温度和工艺corner下,仿真得到的电路性能也都能达到上述指标。     

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