一种具有纹波抑制功能的斩波稳定放大器

基于SMIC 0.18 μm BCD工艺设计了一种低失调、低噪声的斩波稳定放大器。针对斩波调制技术引入输出纹波的问题,设计新型的乒乓结构陷波滤波器来抑制纹波,并采用复合路径多级放大器结构拓展了带宽。通过Spectre仿真验证,放大器增益带宽积为11.7 MHz,共模抑制比为145 dB,电源抑制比为126 dB。蒙特卡罗仿真结果表明,放大器失调电压分布的标准差为3.54 μV,输入噪声谱密度为32.1 nV/Hz,纹波抑制效果达83.1 dB。     

CMOS斩波稳定放大器的分析与研究

对几种放大器失调消除技术的分析比较后,重点阐述了CMOS斩波稳定放大器的调制方式,和放大器的增益与斩波频率和相移的关系,并分析了斩波调制后的噪声和失调电压的理论大小以及斩波的电路实现方法。最后,提出了几种减小调制后残余失调电压的方法,总结了斩波稳定放大器最近的一些研究发现及其在一些新型产品中的应用,并归纳了斩波稳定技术的优缺点和应用范围。     

一种单边输入阻抗可调的斩波放大器

提出了一种单边输入阻抗可调、无需纹波抑制的斩波放大器。通过单独调控电容耦合斩波放大器预充电时序,实现单边输入阻抗可调的放大器设计,这对于存在系统性源阻抗失配的信号检测是有意义的。同时还提出了一种高通型核心放大器,通过降低增益,达到了衰减因斩波调制引入的输出纹波的目的。因此,所提出的斩波放大器不再需要额外的纹波抑制电路。仿真结果显示,该斩波放大器具有61 MΩ~53 GΩ的直流单边输入阻抗可调范围,具有51.4 dB的纹波抑制能力。     

一种适用于微传感器读出电路的低噪声、低失调斩波放大器

提出一种适合微传感器读出电路的高精度折叠共源共栅放大器.基于斩波技术和动态元件匹配技术,降低了折叠共源共栅放大器的噪声和失调,采用低阻节点斩波的方法和低压共源共栅电流镜扩大了放大器可处理的输入信号带宽和输出电压摆幅.芯片在0.35μm 2P4M CMOS工艺下设计并流片,测试表明在3.3V的典型电源电压和100kHz的斩波频率下,斩波放大器具有小于93.7μV的输入等效失调电压典型值,19.6nV/Hz的输入等效噪声,开环增益达83.9dB,单位增益带宽为10MHz.     

一种适用于微传感器读出电路的低噪声、低失调斩波放大器

提出一种适合微传感器读出电路的高精度折叠共源共栅放大器.基于斩波技术和动态元件匹配技术,降低了折叠共源共栅放大器的噪声和失调,采用低阻节点斩波的方法和低压共源共栅电流镜扩大了放大器可处理的输入信号带宽和输出电压摆幅.芯片在0.35μm 2P4M CMOS工艺下设计并流片,测试表明在3.3V的典型电源电压和100kHz的斩波频率下,斩波放大器具有小于93.7μV的输入等效失调电压典型值,19.6nV/Hz的输入等效噪声,开环增益达83.9dB,单位增益带宽为10MHz.     

一种针对小信号探测的低噪声放大器

针对放大器中的直流偏移和低频噪声干扰问题,设计了一种具有4种工作状态的低噪声放大器。该放大器综合利用了斩波技术和自归零技术,通过对噪声进行调制和采样,实现了对以1/f噪声为代表的低频噪声和以失调电压为代表的直流偏移的抑制。鉴于自归零技术是一种离散时间采样技术,该放大器还采用了乒乓结构,通过4种电路状态的交替工作,实现了放大器的连续稳定输出。该放大器芯片基于0.5μm CMOS工艺设计制备,片上面积约1 mm²,供电电压(V_DD)为3～5.5 V,输入共模电压范围为+0.2 V至V_DD-0.2 V。测试结果表明,该放大器的电源抑制比为62 dB,共模抑制比为112 dB。在4 V供电电压和室温条件下,放大器的残余失调电压为4.2μV,在1～400 Hz带宽内的有效输入参考噪声为5.81μV。     

数字温度传感器的带隙基准电压源设计

为了实现温度传感器的数字化输出,设计出一种不随温度变化的带隙基准电压源电路。与传统带隙基准电压源相比较,该电路利用温度系数相反的物理量加权相加得到基准电压,同时在电路中利用斩波调制解调技术,消除运算放大器失调电压的影响。仿真结果表明,该电路的温度系数小于10ppm,电源调整率低,在频率为10KHz时,电源电压抑制比为-66.27d B左右,加入失调电压可以被斩波完全消除。     

基于斩波技术的CMOS运算放大器失调电压的消除设计

实现传感器系统的高分辨率,要求其内部运算放大器具有低失调电压和低噪声的性能,为此介绍了一种可减少运算放大器的失调电压和低频噪声的斩波技术,并基于该技术进行温度传感器中CMOS运算放大电路失调电压的消除设计,最后通过SPICE仿真分析来权衡电路各参数的设定。     

基于GSMC0.13μm工艺的低失调运算放大器设计

针对斩波调制导致的输出纹波和带宽受限的问题,采用复合路径结构,将运放分为高频低增益的主路径和低频高增益的辅助路径,主路径决定带宽,辅助路径决定失调,斩波调制位于辅助路径,解除了带宽限制;将Ping-pong自动调零与斩波调制相结合,减小了运放的失调和斩波调制导致的纹波;采用复合路径混合嵌套米勒补偿的方法来进行频率补偿,...     

一种斩波稳定低噪声Σ-Δ调制器设计

针对Σ-Δ调制器输入失调电压的需求,设计了一种新型低输入失调电压的Σ-Δ调制器。利用斩波稳定运算放大器和新颖的开关电容积分器,动态消除了直流失调电压以及低频噪声(主要包含1/f噪声),使得调制器的输入失调电压微乎其微。基于0.15 μm CMOS工艺,利用Hspice软件对电路进行仿真,同时采用Matlab和TCL对仿真结果进行分析。仿真结果表明,在电源电压为4.5~5.5 V、温度为-40 ℃~85 ℃、各种工艺角下,低频噪声抑制能力增加了15 dB,且当运算跨导放大器的失调电压为10 mV时,Σ-Δ调制器的输入失调电压由9.7 mV下降为0.4 mV。     

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