一种可变带宽的电荷泵锁相环设计

介绍了电荷泵鉴相器原理,提出了在电荷泵鉴相器基础上既能加快锁定时间又能在锁定时减小抖动的自适应带宽锁相环。自适应带宽是根据锁相环路的状态自动增大或减小电荷泵电流。根据此思路对传统电荷泵电路稍加改进,并用ADS2006软件进行仿真,结果表明符合预期的效果。     

应用于BUCK-BOOST的低功耗高精度欠压锁定设计研究

传统的欠压锁定电路离不开外部电路提供的基准电压和偏置电流,同时当进入欠压锁定状态时,基准电路无法关断,不利于芯片的低功耗设计.针对传统电路的缺点,设计了一种不需要外部基准电压和偏置电流,并且电路结构简单、响应速度快、温度漂移低、阈值随PVT变化较小、功耗较低的欠压锁定电路.基于0.18 μm BCD工艺对提出的电路进行...     

基于ADF4193的UHF频率合成器设计

频率合成芯片ADF4193具有小数分频和快速锁定特性。换频时通过增加电荷泵电流以扩大环路带宽,缩短了环路的锁定时间,并采用可编程开关调整环路元件参数来确保环路稳定。UHF跳频频率合成器以ADF4193为核心电路实现设计,采用ADIsimPLL软件仿真环路参数,利用低噪声运算放大器构成的电压放大器来扩大VCO的调谐电压范围,通过调整环路带宽及设计合理的PCB布局来抑制杂散,给出了实测结果。     

低杂散锁相环中电荷泵的设计

采用IBM 0.18 μm CMOS工艺,设计了一款应用于433 MHz ASK接收机中低杂散锁相环的电荷泵电路.设计采用与电源无关的带隙基准偏置电流源和运算放大器,实现了电荷泵充放电电流源的精确匹配,有效抑制了传统电荷泵对锁相环锁定状态中杂散信号的影响.电路在Cadence的Spectre工具下进行仿真,结果表明:当电源电压为1.8 V、参考电流为30 μA、输出电压范围在0.5～1.5 V时,充放电电流精确匹配,杂散小于-80 dB,其性能符合接收机系统要求.     

基于40 nm CMOS工艺可快速锁定的宽带锁相环电路设计

通过改进鉴频鉴相器(PFD)的电路结构,增加一个控制模块自适应调整电荷泵的充放电电流大小,设计了一种可快速锁定的宽频带电荷泵锁相环电路.当鉴频鉴相器输出的相位误差值大于控制模块中的延迟时间τ时,打开控制开关增加电荷泵的电流,从而增加环路带宽,减少环路滤波器的电阻值,实现快速锁定,环路稳定性不变.当环路接近锁定时,调整带宽到预设的优化值,保证了系统性能的最优化.基于SMIC 40nm CMOS工艺,完成电路设计与仿真.结果表明:在电源电压为2.5V时,该锁相环可实现输出频率范围为698~960 MHz,1 700~2 200MHz,2 300~2 700MHz,覆盖GSM,TD-SCDMA,WCDMA,TD-LTE四个通讯标准的工作频段,锁定时间小于12μs.     

电流反馈运放在高速I/O应用中获得最佳性能

电流反馈的结构与电压反馈大不相同.电流反馈非常适合用于高速信号,因为它没有基础增益带宽积的限制,同时也由于其固有的线性度.电流反馈运算放大器的带宽略微受到增益的约束,但不像电压反馈器件那么严重.再者,压摆率并非受到内部偏置电流的限制,而是受到晶体管自身速度的限制.这样在给定偏置电流的条件下可以使用更快的压摆率,而不必采用正反馈或其它压摆率提升技术.     

低压低功耗电流反馈运算放大器设计

基于第三代电流传输器,通过在放大级与输出之间采用隔离补偿电容,以消除低频零点的方式,设计了一种新型的低压低功耗的电流反馈运算放大器.基于TMSC 0.35μmCMOS工艺,在1.5 V电源电压工作条件下,采用Hspice在LEVEL49模型参数下对整个电路进行仿真.仿真结果:直流增益96.3 dB,单位增益带宽765 MHz,静态功耗0.82mW,闭环工作状态下有64.3 MHz的固定带宽.     

分段温度曲率补偿双极工艺带隙基准设计

介绍一种采用双极工艺适用于低压差线性稳压源的带隙基准设计,基准具有使能电路,有效减小锁定状态下的静态功耗,锁定状态下静态电流为34.419pA.针对低压差线性稳压源的应用环境要求,对基准工作温度范围内进行分段曲率补偿技术以降低其温度漂移.-40C～140℃温度范围内基准电源的温度系数达到25.7ppm/℃.该基准无运放,以降低运放失调电压的影响,其电源抑制比为-80.33dB.电源电压在2.5V～6V变化时,基准大小变化0.3mV.     

一种超低功耗欠压锁定电路设计与实现

集成电路的低功耗、高集成度已经成为发展趋势.传统的欠压锁定电路需要外部电路提供带隙基准电压和偏置电流,电路结构复杂;同时,当发生欠压锁定,关断芯片时,却要保证带隙基准电路始终正常工作,不利于芯片功耗的降低.针对传统欠压锁定电路结构的缺点,设计了一种基于三极管的欠压锁定电路,不需要外部电路提供基准电压和偏置电流,电路结构...     

一种AB类输出的高精度CMOS正向电流传输器

基于CSMC 0.5 μm工艺,在两级CMOS运放的基础上,设计了一种结构简单、电压跟随能力强和电流传输精度高的第二代正向电流传输器(CCII ).设计中,通过采用AB类推挽输出方式,达到了降低静态功耗和提高电流驱动能力的目的;应用密勒电容与调零电阻串联的补偿方式,有效地改善了CCII 的频率响应特性;分析了AB输出级晶体管对静态电流的影响.HSPICE仿真结果表明,在1.5 V供电电压下,该CCII 的电压跟随误差仅为0.0534 dB,-3 dB带宽达到201 MHz;电流传输误差为0 dB,-3 dB带宽达到54.4 MHz,X端输入电阻低于0.57 Ω,电流驱动能力为-0.2～1.2 mA,电路功耗为2.54 mW.     

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