基于有源电感的全集成超宽带低噪声放大器

利用有源电感来实现超宽带低噪声放大器(UWB LNA),不但可以减小芯片面积、改善增益平坦度,而且可通过外部调节偏置电压来调谐有源电感的电感值,进而调整设计中没有考虑到的由工艺变化及封装寄生带来的增益退化.采用TSMC 0.35 μm SiGe BiCMOS工艺,利用Cadence设计工具完成了放大器电路及版图的设计.在3.1～10.6 GHz工作频率范围内,通过外部调节电压来调谐有源电感,可使LNA的增益S21在16～19 dB范围内变化,输入输出回波损耗S11,S22均小于-10 dB,噪声为2.4～3.7 dB,输入3阶截点IIP3为-4 dBm.整个电路芯片面积仅为0.11 mm2.     

一种电感值和Q峰值可相互独立调谐的高线性有源电感

设计了一种电感值和Q峰值可相互独立调谐的高线性有源电感。该电感主要由跨导增强模块、互补共源级模块以及单端负阻模块构成。其中,跨导增强模块不仅可以作为正跨导器,并且可实现对电感值的大范围调谐；互补共源级模块不仅可以作为负跨导器,并且可改善有源电感的线性度；单端负阻模块不仅提高了Q值,并且补偿由电感值的调谐导致的Q峰值的变化。最终,通过以上模块的相互配合及其外部端口电压的协同调控,改善了有源电感的线性度,而且实现了在同一频率下Q峰值相对于电感值可大范围独立调谐以及在不同频率下电感值相对于Q峰值可大范围独立调谐的优秀性能。验证结果表明,该有源电感电感值的-1 dB压缩点为-7 dBm；在2.07 GHz的频率下,Q峰值可从240调节到1573,而电感值从11.89 nH仅变化到12.11 nH；在0.989 GHz、2.070 GHz和3.058 GHz的不同频率下,取得了493.7、501.2和508.4的高Q峰值,变化率仅为3%,而相应频率下的电感值分别为16.1 nH、13.4 nH和6.8 nH,变化率为136.7%。     

一种双回转器有源电感

针对基于共源-共栅负跨导器的传统单回转器有源电感(TSAI-CS-CG)的不足,联合采用双回转器结构、负阻网络和负反馈网络,提出了一款兼有大电感值、高Q值、高线性度、宽频带、可调谐特性的双回转器有源电感(DGAI)。基于TSMC 0.13μm RF CMOS工艺,利用是德科技公司的射频高级设计系统（ADS）进行验证。结果表明：电感工作频率范围为0~22.5GHz;Q峰值可达6883;电感的-1dB压缩点高达-17dBm;调节外部偏置,在频率为15GHz下,在频率为15GHz下,电感值可从19.59nH到73.41nH之间进行大范围调节。     

采用调制晶体管和双反馈回路的有源电感

在共源共栅-共漏有源电感的基础上,联合采用调制晶体管和双反馈回路,提出了一种可在不同频率下获得高的品质因子(Q)峰值,且分别可在大、小范围内粗调和细调电感值的新型宽频带可调谐有源电感。基于TSMC 0.18 μm CMOS工艺,利用ADS设计软件进行验证。结果表明,该有源电感在0~8.15 GHz的工作频率范围内,调节主回路的偏置电压,在频率为4.0,4.85,5.95 GHz时,分别获得1 154,6和1 293的高Q峰值。当Q值大于20时,其频率带宽均大于1.5 GHz,可以在43~132 nH之间粗调电感值的峰值。调节从回路的偏置电压,在5.95 GHz固定频率下,获得418~3 517的高Q峰值,且可以在10%比例范围内细调电感值的峰值。     

有源电感复用型2.4GHz/5.2GHz双频段LNA

采用可调谐有源电感复用结构,设计了一款用于3G TD-SCDMA和WLAN的2.4GHz/5.2GHz双频段低噪声放大器(DB-LNA)。2.4GHz频段电路采用折叠共源共栅(FC)结构,5.2GHz频段电路采用共栅(CG)结构。FC和CG结构均采用可调谐有源电感,通过调谐有源电感的等效阻抗,优化匹配到源阻抗。基于TSMC 0.18μm CMOS工艺,实现了有源电感复用型DB-LNA。ADS仿真结果表明,频率为2.4GHz时,S21=35dB,NF=4.42~4.59dB,IIP3=0dBm,P-1dB=-14dBm;频率为5.2GHz时,S21=34dB,NF=2.74~2.75dB,IIP3=-5dBm,P-1dB=-9dBm。     

一种新型双频Wilkinson功分器的设计

为了实现功分器工作在任意两个频率的目的,设计了一种新型功分器.基于奇偶模分析方法,利用微波网络理论推导了电路参数的设计公式,通过求解相应的非线性方程组获取了具体电路参数.制作了一个工作频率为1GHz和2.6 GHz的双频Wilkinson功分器.实物测试结果表明,该功分器在两个中心频率的传输衰减小于3.3dB,端口回波损耗大于21 dB,端口隔离度大于28 dB,在中心频率100 MHz的通带范围内都具有良好性能,验证了设计方法的可靠性.     

有源电感复用型2.4 GHz/5.2 GHz双频段LNA

采用可调谐有源电感复用结构,设计了一款用于3G TD-SCDMA和WLAN的2.4 GHz/5.2 GHz双频段低噪声放大器(DB-LNA)。2.4 GHz频段电路采用折叠共源共栅(FC)结构,5.2 GHz频段电路采用共栅(CG)结构。FC和CG结构均采用可调谐有源电感,通过调谐有源电感的等效阻抗,优化匹配到源阻抗。基于TSMC 0.18 μm CMOS工艺,实现了有源电感复用型DB-LNA。ADS仿真结果表明,频率为2.4 GHz时,S₂₁=35 dB,NF=4.42～4.59 dB,IIP3=0 dBm,P-1dB=-14 dBm;频率为5.2 GHz时,S₂₁=34 dB,NF=2.74～2.75 dB,IIP3=-5 dBm,P-1dB=-9 dBm。     

基于电长度可调的可重构功分器设计

根据分支线耦合器的功率合成效率会受输入功率相位差的影响,通过含变容二极管的π型电路将其级联在3dB Wilkinson功分器的后端,实现原功分器的功率再分配。通过调节变容二极管的偏置电压改变π型电路的等效电长度实现相位差,可实现功分器的分配比例可调。在此原理上,基于ADS软件设计了两款工作频率为2.5GHz的可重构功分器,可分别实现分配比例在0~25dB(约1∶1~300∶1)和-15.5~15.5dB(约1∶35~35∶1)范围内连续可调,且其回波损耗和输出端口间隔离度均优于20dB,适用于射频与微波系统中的实时功率分配与合成。     

2.5Gb/s CMOS光接收机限幅放大器

采用SMIC 0.18μm CMOS工艺设计了光接收机限幅放大器.该放大器采用全差分结构,利用退化电容技术增加高频时放大器的等效跨导,并在Cherry-Hooper结构里引入有源电感反馈代替传统的电阻反馈来扩展带宽.Hspice仿真结果表明限幅放大器具有46dB的中频增益、3.2GHz带宽,当输入电压信号从3.6mVPP到1.7VPP变化时,50Ω负载线上的输出电压限幅在340mVPP,输出眼图稳定清晰.核心电路功耗20.431mW.     

一种采用有源电感的可调增益小面积超宽带低噪声放大器

设计了一款采用可调谐有源电感（TAI）的可调增益的小面积超宽带低噪声放大器(LNA),输入级采用共基极结构,输出级采用射随器结构,分别实现了宽带输入和输出匹配;放大级采用带有反馈电阻的共射共基结构以取得宽的带宽,并采用TAI作负载,通过调节TAI的多个外部偏压使LNA的增益可调。结果表明,该LNA在2~9GHz的频带内,通过组合调节有源电感调节端口的偏压可实现S21在16.5~21.1dB的连续可调;S11小于-14.7dB;S22小于-19.3dB;NF小于4.9dB;芯片面积仅为0.049mm2。     

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.