一个高线性度的CMOS DVB-S前端芯片

提出了基于CMOS工艺的直接频率变换的DVB-S射频前端电路设计.设计采用了T型匹配网络的可变衰减器、具有单端到双端变换功能的低噪声放大器以及低噪声混频器.通过使用衰减器,系统处理线性度的能力得到很大的提高.设计和流片基于SMIC 0.18μm CMOS工艺.测试结果表明,该设计能够达到超过30dB的动态范围,噪声系数小于3dB,消耗电流为10mA.在低增益情况下,具有+20dBm的输入三阶交调能力.     

无线应用CMOS低噪声放大器的设计

基于射频CMOS集成电路技术, 设计出用于无线通信系统的CMOS低噪声放大器.对影响其增益、噪声系数的阻抗匹配进行了分析.采用TSMC的0.35 μm射频工艺库,在ADS仿真平台上对低噪声放大器电路进行了仿真.其中,低噪声放大器设计成差分结构,提供了13 dB增益、-10 dBm IIP3、-13 dBm P1dB、1.9 dB的噪声系数和55 mW的功耗.     

应用于微小卫星的CMOS图像传感器芯片设计

针对小卫星以至微纳卫星领域的应用需求,文章对具有抗辐照能力的CMOS图像传感器的芯片架构和关键技术进行了研究,着重对行列选电路、低噪声信号读出、可编程增益放大器和片上ADC等电路设计技术进行了分析和仿真验证.基于0.35 μm CMOS抗辐照技术和工艺开展了芯片的关键电路仿真、设计和整体版图设计验证.流片后的测试结果表明,该CMOS图像传感器具有高动态、低噪声和抗辐照特点,其噪声电子为42 e-,动态范围为69 dB,当辐射总剂量大于100 krad(Si)时,器件噪声指标符合预期.     

基于噪声抵消技术的宽带低噪声放大器设计

采用0.18μm CMOS工艺,针对DMB-T/H标准数字电视调谐器应用,设计了一个基于噪声抵消技术的宽带低噪声放大器.详细分析了噪声抵消技术的原理,给出了宽带低噪声放大器的设计过程.仿真结果表明,在48～862 MHz频率范围内输入输出反射系数均小于-20 dB,噪声系数低于3 dB,增益大于17 dB,1 dB压缩点为-6dBm.在1.8V电压下,电路功耗为10.8mW.     

10.4~28 GHz的超宽带6位数字衰减器设计

基于中芯国际40 nm CMOS工艺设计并实现了一种超宽带6位数字衰减器,其工作频率为10.4～28 GHz。该衰减器采用内嵌式开关型结构,6位衰减单元的设计采用T型、桥T型和π型三种拓扑结构。该6位衰减器可以实现0.5 dB的衰减步进,31.5 dB的动态衰减范围。采用大衰减量幅度补偿电路和高匹配特性的衰减位级联结构,衰减器在10.4～28 GHz的频段范围内具有平坦的64态衰减量,衰减器的整体前仿真插入损耗为1.73～2.08 dB,后仿真插入损耗为4.32～6.31 dB,64态的输入输出回波损耗均小于-10 dB。     

非平衡变换低噪声放大器的设计

在具有非平衡变换功能的2.4GHz CMOS低噪声放大器的设计中,采用单端低噪声放大器与有源Balun结构通过耦合电容相级联的方法实现.单端低噪声放大器主要侧重优化它的噪声系数,并使其具有较高的增益.有源Balun结构则侧重于减小它的增益误差和相位误差.最后把单端低噪声放大器和有源Balun结构进行联合仿真.仿真结果显示:设计的低噪声放大器在中心频率上噪声系数为0.71dB,增益为25.767dB,输入输出反射系数均小于-20 dB,电路总功耗为13.86mW,并且实现了完全的非平衡转换.     

低功耗CMOS低噪声放大器的设计

针对低功耗电路设计的需求,提出了一种低功耗约束下CMOS低噪声放大器的设计方法,并与传统的设计方法进行了对比。模拟结果表明,按照该方法基于0.18μm CMOS工艺设计的工作于1.58 GHz的低噪声放大器,在仅消耗1.9 mA电流的条件下,噪声指数小于1 dB。     

用于便携式GPS接收机中的5.4mW低噪声高增益CMOS射频前端电路设计

设计了应用于便携式GPS接收机射频前端中的CMOS低噪声放大器和正交混频器. 该电路中的低噪声放大器采用带源端电感负反馈的输入级,并引入功耗约束下的噪声和输入同时匹配技术. 正交混频器基于吉尔伯特单元. 电路采用TSMC 0.18μm RF CMOS工艺实现,总的电压转换增益为35dB,级联噪声系数为2.4dB,输入1dB压缩点为-22dBm,输入匹配良好,输入回损为-22.3dB, 在1.8V电压供电下,整个全差分电路功耗为5.4mW.     

一种适用于5G通信的分布式低噪声放大器

宽带低噪声放大器是5G无线通信系统中的关键模块。针对6 GHz以下5G通信应用频段,基于65 nm CMOS工艺,设计了一种三级均匀分布式宽带低噪声放大器。在增益单元电路中,采用噪声抵消技术降低了噪声,同时实现了信号的单转双变换,并通过电流复用技术提升了增益。栅极人工传输线的终端采用了RL型负载,进一步改善了放大器的噪声性能。仿真结果表明,该分布式低噪声放大器的带宽为0.5~5.7 GHz,带内增益达到24.2 dB,噪声系数低于4.5 dB,而最小噪声系数仅为2.7 dB。     

ADS下CMOS低噪声放大器的设计优化

运用仿真工具ADS,通过对CMOS共源共栅低噪声放大器的共源级栅宽,源级电感以及栅极电感值的扫描仿真,以Smith阻抗圆图的形式给出了一个直观的LNA设计优化流程,近似实现了最佳噪声源阻抗和输入阻抗的同时匹配.按照该方法设计的基于0.18 μm CMOS工艺,工作在1.58 GHz的低噪声放大器,其噪声系数为1.3 dB,S11为-28.4 dB,功耗为3.42 mW,从而很好地证实了该方法的可行性.     

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.