低功耗高速率IR-UWB发射机设计与实现

针对高速无线通信的应用场景,该文提出了一种低功耗高速率的脉冲超宽带发射机架构。发射机采用注入锁定环形振荡器产生射频载波,同时基带信号通过基于有限长单位冲激响应滤波器的模拟延迟线产生发射所需要的波形,不仅减少了发射机的功率损耗,而且更好地满足了FCC MASK的要求。该发射机电路采用40 nm CMOS工艺设计和仿真验证,仿真结果表明,所提出的脉冲超宽带发射机可实现OOK和BPSK调制,具有1.1 GHz和2.2 GHz两种发射带宽,最大数据传输速率可达499.2 Mb/s,其能量效率为11.8 pJ/bit。     

GPRS数据传输模块的设计与实现

本文旨在利用GPRS实现无线传输数据.首先介绍基于通用分组无线业务(GPRS)的无线数据传输技术,然后对应用单片机C51实现GPRS模块串口通信进行研究,给出硬件设计原理图,并且给出程序设计流程图.对基于C51的GPS和GPRS模块进行了仿真,提出用GPRS技术进行无线数据传输的实现方法.实践证明,利用GPRS传输数据与传统的数据传输方式相比,具有耗资小、体积小、分布广、使用灵活等优点.     

低功耗无线动物神经信号采集模块设计

文中根据RF无线射频原理,提出了一个适用于小体型动物的纯模拟、低功耗的无线神经信号采集模块设计方案。相比于数模混合方案,纯模拟的实现方案具有尺寸小、功耗低以及结构简单等优势。整个采集模块可以分为模拟前端放大和无线数据传输两部分。通过选用低功耗、低噪声的仪表放大器INA333和运算放大器OPA333构成模拟前端放大电路的两级放大结构,降低了电路的功耗和尺寸。通过添加反馈电感实现的反馈增强效应降低了Colpitts振荡器功耗。采用三极管极间电容对振荡器进行FM调制构成纯模拟无线数据传输电路,使得采集模块具有小尺寸、低功耗以及无线数据传输的特点。电路仿真以及实验测试结果均表明,该模块可以完成动物神经信号的无线采集,具有一定的实用性。     

甚低功耗15Ms/s逐次逼近型ADC的设计实现

采用一种新颖的甚低功耗SAR ADC结构技术,基于SMIC 0.18μm CMOS工艺,设计实现了一个8bit、15Ms/s SAR ADC的芯片电路.该ADC利用电荷分享技术实现数据的采样/保持和逐次逼近转换过程,同时采用了异步时序控制技术代替传统的同步时序控制方式,对SAR控制逻辑进行优化设计,使其在功耗和速度方面都达到优良的性能.仿真结果显示该ADC能在15Ms/s的采样率下正常工作,平均功耗仅为518μW,整体性能优值FOM值达到了0.18pJ/Cony,远低于传统结构.     

一种基于新型同步算法的脉冲UWB能量检测接收器设计

在RFID和无线传感器网络等应用系统中,脉冲UWB(IR-UWB)技术的低功耗和低成本特点具有很大的优势。为了有效地降低功耗和成本,采用了一种基于能量检测,使用开关键控(OOK)调制的IR-UWB接收器,提出了一种使用能量补偿与自适应门限的新型同步与检测算法,此算法降低了接收器的能耗与硬件复杂度。通过对该接收器的仿真及用FPGA硬件实现,表明此算法降低了同步时的功耗及前导序列长度,提高了传输效率,同时保持了系统性能。测试结果表明此接收器架构能够满足在数据率10Mb/s时,功耗仅为1nJ/bit左右,具有低功耗、低复杂度的特点。     

应用于无线传感网络的低功耗10bit 300Ksps多通道逐次逼近型模数转换器的设计

本文给出了一款可应用于无线传感网络的低功耗10bit 300Ksps的逐次逼近型模数转换器(SAR ADC)的设计。采用了单端结构低功耗的拆分式电容阵列DAC和具有轨到轨输入级的比较器来实现本文中的ADC,可以减小功耗同时扩展满量程输入范围。为了实现功耗优化,采用2V的低电源电源供电。设计的ADC还具有4个模拟信号通道,使其更适用于无线传感网络的应用。电路样片采用3.3V 0.35μm 2P4M CMOS工艺实现,占用了1.23mm2的芯片面积,测试结果表明在2V供电166Ksps的采样速率下,ADC的功耗只有200uW,计算得到的信噪比为58.25dB,有效位数为9.38bit,品质因子FOM为4.9pJ/conversion-step。     

一种12 bit 200 MS/s 低功耗 SAR-TDC ADC北大核心

为了满足低电压条件下高速高精度采样需求，设计了一种电压-时域两级混合结构流水线模数转换器(ADC)。该流水线ADC的第一级逐次逼近型(SAR) ADC将电压转换为8 bit数字，残差电压变换为时域延时信息后，第二级4.5 bit时间数字转换器(TDC)将延时转换，最终校准输出，实现12 bit精度转换。通过采用多电压供电、改进残差电压转移和放大器结构，以及优化时间判决器，提升了ADC的动态性能和采样速度，降低了采样功耗。该ADC基于40 nm CMOS工艺设计和仿真。采样率为200 MS/s时，功耗为9.5 mW,动态指标SNDR、SFDR分别达到68.4 dB、83.6 dB,优值为22 pJ·conv-1·step-1,能够满足低功耗高速采样的应用需求。     

用89C52单片机实现FSK调制解调

文章介绍了在陀螺测斜仪的电缆遥测系统中 ,用 89C52单片机实现频移键控调制解调 (FSKmodem)的原理和方法。用此方法可以得到数据传输率为 4 80 0bit/s的FSKmodem ,因而有效地解决了陀螺测斜仪的通信问题。     

UWB通信系统简介

UWB(Ultra Wide Band)即超宽带通信,它使用大于0.5GHz或大于中心频率20%的带宽、通过微弱的脉冲信号进行通信,最大数据传输速率可以达到几十Mb/s～几百Mb/s。UWB与现有的无线技术的显著不同是不需要使用载波,而是通过发送纳秒级脉冲来传输数据,而且信号传输时的功耗只有几十μW。UWB在保证了高数据速率传输的同时解决了移动终端的功耗问题。因此它被认为是对目前被炒得沸沸扬扬的无线互联(Wi-Fi)技术最具竞争性的技术。UWB简介UWB技术多年来一直是美国军方使用的作战技术之一,如它可以实现穿墙视物等功能。这项技术在通信领域所具…     

一种低功耗OOK调制超宽带发射机的实现

设计了一种低功耗OOK调制方式的脉冲超宽带发射机。该发射机的中心频率和脉冲宽度可调;优化了偏置电路,使环形振荡器不易受工艺和温度的影响;在传输数据的间隔,关断相应电路,以实现低功耗。基于TSMC 0.13μm CMOS工艺,对电路进行仿真。结果显示,发射机可以实现1~40Mb/s的数据传输速率,脉冲宽度为1ns,中心频率为4GHz,输出脉冲峰峰值为550mV,功率谱密度符合FCC频谱规范,在10Mb/s数据传输速率下,功耗为320μW。     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.