低功耗、高线性度的电流模可编程增益放大器

本文设计了一种电流模式下,带电流模直流失调消除（DCOC）电路的class-AB的可编程增益放大器。电路基于电流放大器,可以实现40dB的增益动态范围,增益步长为1dB。电流模可编程增益放大器由0.18-μm CMOS工艺实现,电路具有较宽的电流增益范围、较低的直流功耗和较小的芯片面积。放大器电路芯片面积为0.099μm2,在1.8V电压下静态电流为2.52mA。测试结果表明电路增益范围为10dB到50dB,增益误差为±0.40dB,OP1dB为11.80dBm到13.71dBm,3dB带宽为22.2MHz到34.7MHz。     

1.8～2.7GHz可调谐八波段时分LTE多模接收机前端的分析与设计

摘要：本文阐述了支持八波段可调谐时分LTE多模接收机前端的分析与设计,覆盖1.8～2.7GHz频率范围并支持5/10/15/20MHz三种带宽和QPSK/16QAM/64QAM 三种调制方式。零中频可调谐接收机前端的设计包括了可调谐窄带可变增益低噪声放大器,电流型下变频混频器和二阶低通输出跨阻放大器,可变增益预放大器,可调谐四阶切比雪夫低通信道选择滤波器和截止频率矫正电路,中频可变增益放大器。 窄带低噪声放大器可以在调谐范围内自由调节中心频率,从而替代了传统多模接收机中的低噪声放大器阵列,节省了芯片面积。模拟基带部分也可以通过数字接口调节增益和信道选择带宽。芯片在SMIC 0.13μm 1P8M CMOS上实现,测试结果显示双边带噪声系数达到4.6dB, 带外IIP3达到-14.5dBm,30～94dB增益范围。1.2V电源电压下芯片消耗功耗为54mA。     

一种应用于IEEE 802.11 b/g/n无线局域网收发机的CMOS模拟基带电路

本文提出了一种应用于直接变频无线局域网收发机的模拟基带电路,该电路采用标准的0.13微米CMOS工艺实现,包括了采用有源RC方式实现的接收4阶椭圆低通滤波器、发射3阶切比雪夫低通滤波器、包含直流失调消除伺服环路的接收可变增益放大器及片上输出缓冲器。芯片面积共1.26平方毫米。接收基带链路增益可在-11dB至49dB间以2dB步长调节。相应地,基带接收输入等效噪声电压（IRN）在50 nV/sqrt(Hz) 至30.2 nV/ sqrt(Hz)间变化而带内输入三阶交调（IIP3）在21dBm至-41dBm间变化。接收及发射低通滤波器的转折频率可在5MHz、10MHz及20MHz之间选择以符合包含802.11b/g/n的多种标准的要求。接收基带I、Q两路的增益可在-1.6dB至0.9dB之间以0.1dB的步长分别调节以实现发射IQ增益失调校正。通过采用基于相同积分器的椭圆滤波器综合技术及作用于电容阵列的全局补偿技术,接收滤波器的功耗显著降低。工作于1.2V电源电压时,整个芯片的基带接收及发射链路分别消耗26.8mA及8mA电流。     

用于UHF RFID阅读器的自动频率校准模拟基带

基于0.18μm标准CMOS工艺,提出了一种适用于超高频射频识别阅读器的自动频率校准模拟接收基带。该模拟基带包含直流偏移消除电路和信道选择滤波器,直流偏移消除电路有6dB的预增益,信道选择滤波器采用8阶巴特沃斯结构。在频率校准电路的作用下,滤波器能够分别对250kHz和1.35MHz截止频率进行校准,校准时间小于3μs。后仿真结果表明,在3.3V电源电压下,整个模拟基带消耗12mA电流,截止频率为1.35MHz,10dB增益条件下带内输入3阶交调达到12dBm,在30dB增益时,带内噪声系数为26dB。     

一种适用于WiMAX/LTE发射机的高线性、可变带宽、可变增益滤波器设计

采用0.13μm RF CMOS工艺,实现了一个高线性、带宽可变、增益可调的四阶巴特沃兹低通滤波器。此滤波器带宽2.1～12MHz,7种带宽控制,30dB增益范围,1dB增益步进,增益步进误差小于0.05dB,在最大带宽下,输出信号频率1.5MHz,功率4dBm时的三阶谐波失真小于-65dB。芯片面积为0.45mm2。电源电压1.2V,在最大带宽下功耗为12mW,最小带宽下功耗为4mW。此低通滤波器已经成功地应用在WiMAX/LTE直接变频发射机中。     

一种高增益且可调谐的1~3 GHz宽带LNA

提出了一种增益高且增益可调谐的1~3 GHz宽带低噪声放大器(HTG-LNA)。在输入级,采用带有RC串联负反馈的共基-共射电流镜结构,实现了良好的输入匹配,并提高了电路的稳定性;在中间级,采用以有源电感作为负载的共基-共射达林顿电路结构,在保证宽带的同时实现了较高的增益与增益的可调谐;在输出级,采用带有电流镜的射极跟随器结构,获得了较大的输出功率和良好的输出匹配。基于稳懋0.2 μm GaAs HBT工艺进行验证,结果表明,该HTG-LNA的电压增益大于37 dB,最高可达50.7 dB;功率增益大于37.4 dB,最高可达51 dB;最大增益可调谐幅度为2.2 dB;输入回波损耗小于-7.11 dB;输出回波损耗小于-11.97 dB;噪声系数小于3.23 dB;稳定因子大于5.61;在5 V工作电压下,静态功耗小于65 mW。     

一种V/U频段零中频发射信道小型化设计

针对V/U频段,提出了一种宽带发射机的前端设计方法,其中包括射频信道设计、频率合成器的设计以及基带电路设计。鉴于小型化的设计思想,射频前端采用零中频发射机架构,通过合理的滤波、放大等信号处理,输出1 dB压缩点为16 dBm。频率合成器采用集成VCO的锁相环芯片ADF4351,为满足高速跳频通信体制,采用兵乓环高速换频,实现单边带相位噪声优于-125 dBc/Hz@100 kHz,频率切换时间小于10μs。基带电路采用正交调制器LTC5598和12位双通道DA转换器AD9716,可实现最大带宽为40 MHz的I/Q双路同时调制。通过FPGA或DSP基带处理,可广泛用于V/U小型化发射机设计。     

一种基于ADS的电调谐滤波器的新设计

设计了一种用于跳频通信系统接收机射频前端的UHF频段电调谐滤波器。使用安捷伦公司的 微波仿真软件ADS对电调谐滤波器进行结构设计和参数优化。对制成品的实际测试表明,该 调谐滤波器工作频段为225～400 MHz,3 dB带宽6.5～15 MHz,通带增益24～27 dB,矩形系 数小于6.2,其性能指标完全达到设计要求,在不同的频点都具有良好的电参数指标。所提 方法对电调滤波器的设计具有指导作用。     

片上自动调谐的可编程有源RC滤波器

研制了一款可编程6阶巴特沃斯有源RC滤波器.为提高滤波器中运算放大器的增益带宽积,设计了一种新型的前馈补偿运算放大器.为消除工艺偏差和环境变化对截止频率的影响,设计了一种片上数字控制频率调谐电路,并采用TSMC 0.18 μm CMOS工艺进行了流片.滤波器采用低通滤波结构,测试结果表明,3 dB截止频率为1～32 MHz,步进1 MHz,带内增益0 dB,带内纹波0.8 dB,2倍带宽处带外抑制不小于24 dBc,5倍带宽处带外抑制不小于68 dBc,滤波器等效输入噪声为340 nV/√Hz@1MHz,调谐误差为±3％.滤波器裸芯片面积0.87 mm×1.05 mm.采用1.8V电源电压,滤波器整体功耗小于20 mW.     

应用于直接变频架构直播卫星调谐器中的具有宽调谐范围的连续时间低通滤波器

本文用0.35微米锗硅BiCMOS工艺设计了七阶巴特沃兹跨导电容低通滤波器及其片上自动调谐电路,该低通滤波器适用于采用直接变频架构的直播卫星调谐器。该滤波器的-3dB带宽截止频率具有从4MHz到40MHz的宽调谐范围。成功实现了一种新颖的片上自动调谐方案,用来调谐和锁定滤波器的-3dB带宽截止频率。测试结果表明,该滤波器具有-0.5dB的通带电压增益,+/- 5%的带宽精度,30nV/Hz1/2的等效输入噪声,-3dBVrms 通带电压三阶交调点,27dBVrms 阻带电压三阶交调点。I/Q正交两路滤波器及其调谐电路采用5V电源,在滤波器的-3dB带宽截止频率为20MHz的情况下,消耗电流13毫安,占用芯片面积0.5mm2。     

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.