Nanotechnology: high-speed integrated nanowire circuits

Macroelectronic circuits made on substrates of glass or plastic could one day make computing devices ubiquitous owing to their light weight, flexibility and low cost. But these substrates deform at high temperatures so, until now, only semiconductors such as organics and amorphous silicon could be used, leading to poor performance. Here we present the use of low-temperature processes to integrate high-performance multi-nanowire transistors into logical inverters and fast ring oscillators on glass substrates. As well as potentially enabling powerful electronics to permeate all aspects of modern life, this advance could find application in devices such as low-cost radio-frequency tags and fully integrated high-refresh-rate displays.     

可编程语音压缩专用处理器设计

为了提高通信系统的保密性,降低制造成本,需要进行专用处理器的设计。基于正弦激励线性预测(SELP)算法模型,设计了一款多速率语音专用处理器。芯片使用可重构体系结构和超长指令字(VLIW),优化了高复杂度函数。仿真结果表明:该处理器对0.6kb/s速率SELP算法的执行效率明显优于通用数字信号处理器(DSP)。处理器内部程序数据外部不可见,指令并行度显著提高,常用函数可被修改,从而达到高保密性、低复杂度、易开发性。     

可编程控制技术在采煤机中的应用

介绍了PLC的特点及PLC在采煤机应用中出现的问题,并提出了解决问题的对策.     

可编程逻辑互连网络的设计

半导体技术的迅速进步要求数字系统设计过程的同步提升。例如英特尔4004处理器这样的早期集成电路完全是手工设计的，其中包括了布局工艺图。对于在1971年利用100m技术工艺过程构建的2300个晶体管晶件而言，这是一个合理的努力。与之形成对照的是2002年7月公布的最新的英特尔奔腾2微处理器。它包含了2．2亿个晶体管，使用了0．180m工艺过程，设计这样一个大型器件要求几百个工程师依靠高级的CAD工具来处理其复杂性。在过去的5至10年内，每一个新的英特尔处理器都是设计的顶峰，为其他器件的跟进设置了标准。随着当前制造技术达到了深一亚微层次，为创建一个可以工作的设计所要求的低层次设计努力就越来越多。同时可编程逻辑器件的功能已经提升。目前的现场可编程门阵列（FPGA）可以实现整个数字系统，它们对于系统层次设计者的吸引力在不断地增加。但是在许多情况中，它们的性能是不够的，或者它们没有包含足够的内存，或者缺乏关键的知识产权核心。因此存在着不断增加的需求，要把可编程逻辑技术与客户化的亚微VLSI技术相结合。如果说在可编程逻辑中存在着一个没有被完全理解的具体方面的话，那就是互连。它占用了最大的面积而且要为大多数的延时负责。可编程逻辑器件的90％是布局，10％是逻辑。本书把焦点放在了90％上面，即可编程布局上。它介绍了互连设计的最新研究成果，重点是互连结构自动生成的知识与工具。     

一种应用于FSK调制器的数字可编程振荡器

介绍了一种可用作FSK调制器的数字可编程振荡器(DPO)的设计。该振荡器使用一片PLL电路LM565,其VCO的中心振荡频率由8031单片机经由CMOSCD4066开关所接的电阻阵列来控制。在88KHz-678KHz数字可变的频率范围内获得了良好的方波和三角波。将电路改动为一个正弦的DPO后,得到了一个由8031控制的相位连续的BFSK调制输出。     

可编程逻辑器件PLD的故障检测与诊断

本文提出的可编程逻辑器件易测试方法，充分利用了ＰＬＤ本身固有的可编程特点，简化了器件故障诊断的难度；所有延时、逻辑故障全部可以检测，对延时故障和交叉点故障具有诊断功能，故障检测、诊断十分简便     

锻压设备专用可编程序控制器的研究

本文研究了一种以单片机为主机的锻压设备专用可编程序控制器(FPC).文中阐述了FPC的系统工作原理和系统结构,提出了系统增强抗干扰能力和增强可靠性方面的措施.     

Zigbee接收机内嵌CMOS程控增益放大器设计

针对低中频结构Zigbee接收机,设计一个CMOS程控增益放大器,在低功耗下实现了宽dB线性动态范围和高线性度。程控增益放大器提供70dB数字控制的线性动态范围,增益步长为2dB,增益误差≤±1dB,工作带宽1MHz～3MHz,最大增益时IIP3为1.86dBm,功耗3.14mW。采用SMIC 0.18 CMOS工艺,供电电压1.8V。     

Silver nanowire ring resonator

We demonstrate a silver nanowire ring resonator with a ring diameter of 10.2 μm. The ring cavity is formed by coupling both ends of a 145-nm-diameter single silver nanowire into a closed loop. A Q-factor of 160 and a free spectral range of 10.6 nm are obtained for light centered around 800 nm. The self-coupled ring structure offers opportunities for realizing compact plasmonic resonators with tight confinement for hybrid optical and plasmonic signal processing.     

可编程序控制器在精镗机床上的应用

本文介绍了以日本三菱电机公司生产的Ｆ１－４０ＭＲ可编程序控制器来控制精镗机床的加工程序，特别着重使用其步进指令来编制程序，实践证明，使用此法后，具有机床工作性能稳定、抗干扰性强和复电后能继续加工等优点。     

可编程序控制器应用分析

通过对一个PLC控制系统的分析，说明在PLC的应用中，改变传统继电器控制电路的思考方法，充分利用PLC内部资源，可以进一步节省投资，提高可靠性和自动化程度。     

PLL频率合成器芯片MC145157—2及其应用

介绍了ＰＬＬ频率合成器芯片ＭＣ１４５１５７２的性能及其在锁相环电路中的应用     

可编程数字温度传感器

介绍数字温度传感器DS1820器件的内部结构、特性和工作原理.详细讨论DS1820温度传感器和单片机接口电路,软件设计以及在测控系统中的应用.     

基于MatLab的线性网络及其灵敏度分析

将线性电路网络转换成信号流图,以系统环节的信息变换、环节问的信息传递和互连方式来代替实际的电路网络,消除电流的负载效应,明确信号间的运算关系.针对网络分析中的灵敏度问题,通过附加灵敏电源点的方式,推出灵敏度计算关系.根据MatLab的数值计算与符号运算功能,给出具体算例的计算模型,得到电路参数变化的全程灵敏度曲线,验证所述方法的有效性.     

有限长金属纳米线调控纳米线波导的传输特性研究

基于有限元方法,通过改变有限长金属纳米线的长度、半径、介质有效折射率以及有限长金属纳米线和波导之间的距离,研究了有限长金属纳米线对纳米线波导传输特性的调控效果。结果表明:沿有限长金属纳米线长度方向,表面等离极化激元在两金属纳米线耦合区域内形成共振。随着有限长金属纳米线长度的增加,透射率逐渐减小,并呈周期性变化。随着金属纳米线半径和介质衬底有效折射率的增大,复合波导的透射率均相应增大。透射率与两根纳米线间距紧密相关,当金属纳米线取不同半径值,两根纳米线间距为20nm左右时透射率均达到最小值;当两根金属纳米线间距较大时,透射率不再明显变化。     

Tunable nanowire nonlinear optical probe

One crucial challenge for subwavelength optics has been the development of a tunable source of coherent laser radiation for use in the physical, information and biological sciences that is stable at room temperature and physiological conditions. Current advanced near-field imaging techniques using fibre-optic scattering probes have already achieved spatial resolution down to the 20-nm range. Recently reported far-field approaches for optical microscopy, including stimulated emission depletion, structured illumination, and photoactivated localization microscopy, have enabled impressive, theoretically unlimited spatial resolution of fluorescent biomolecular complexes. Previous work with laser tweezers has suggested that optical traps could be used to create novel spatial probes and sensors. Inorganic nanowires have diameters substantially below the wavelength of visible light and have electronic and optical properties that make them ideal for subwavelength laser and imaging technology. Here we report the development of an electrode-free, continuously tunable coherent visible light source compatible with physiological environments, from individual potassium niobate (KNbO3) nanowires. These wires exhibit efficient second harmonic generation, and act as frequency converters, allowing the local synthesis of a wide range of colours via sum and difference frequency generation. We use this tunable nanometric light source to implement a novel form of subwavelength microscopy, in which an infrared laser is used to optically trap and scan a nanowire over a sample, suggesting a wide range of potential applications in physics, chemistry, materials science and biology.     

A III-V nanowire channel on silicon for high-performance vertical transistors

Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.     

Growth of nanowire superlattice structures for nanoscale photonics and electronics

The assembly of semiconductor nanowires and carbon nanotubes into nanoscale devices and circuits could enable diverse applications in nanoelectronics and photonics. Individual semiconducting nanowires have already been configured as field-effect transistors, photodetectors and bio/chemical sensors. More sophisticated light-emitting diodes (LEDs) and complementary and diode logic devices have been realized using both n- and p-type semiconducting nanowires or nanotubes. The n- and p-type materials have been incorporated in these latter devices either by crossing p- and n-type nanowires or by lithographically defining distinct p- and n-type regions in nanotubes, although both strategies limit device complexity. In the planar semiconductor industry, intricate n- and p-type and more generally compositionally modulated (that is, superlattice) structures are used to enable versatile electronic and photonic functions. Here we demonstrate the synthesis of semiconductor nanowire superlattices from group III-V and group IV materials. (The superlattices are created within the nanowires by repeated modulation of the vapour-phase semiconductor reactants during growth of the wires.) Compositionally modulated superlattices consisting of 2 to 21 layers of GaAs and GaP have been prepared. Furthermore, n-Si/p-Si and n-InP/p-InP modulation doped nanowires have been synthesized. Single-nanowire photoluminescence, electrical transport and electroluminescence measurements show the unique photonic and electronic properties of these nanowire superlattices, and suggest potential applications ranging from nano-barcodes to polarized nanoscale LEDs.