基于802.11a标准的CMOS正交调制器和上变频器

采用0.18μm CMOS工艺,设计并实现了应用于WLAN IEEE 802.11a的正交调制器和上变频器.正交调制器在传统的Gilbert单元基础上,采用负反馈跨导放大器来提高线性度;上变频器采用LC谐振网络作混频器负载来提高增益和电压输出摆幅.测试结果表明,在1.8V电源电压下,谐振频率点的1dB压缩点P1dB为-3.6dBm,功率转换增益为-3.6dB,电流消耗大约45.8mA.     

一种5 GHz WLAN CMOS正交调制器和上变频器的设计

介绍了应用于WLAN IEEE 802.11a的正交调制器和上变频器的设计,给出了详尽的优化方法。正交调制器在传统Gilbert单元的基础上,采用负反馈跨导放大器来提高线性度;上变频器采用RLC谐振网络作Gilbert单元负载来提高增益,增加电压输出摆幅。电路采用TSMC 0.18μm 6层金属混合信号/射频CMOS工艺实现。在1.8 V电源电压下,静态电流为30 mA。测试结果表明,在谐振频率点的1 dB压缩点P1-dB为-8 dBm,电压增益为-2.4 dB,本振泄漏小于-50 dBm。     

一种新型高线性度5 GHz WLAN正交调制器和上变频器的设计

提出了一种应用于IEEE802.11a无线局域网中的5 GHz高线性度新型正交调制器和上变频器.我们在正交调制器中运用了一种新型的结构来获得很高的线性度,在上变频器电路中,LC谐振网络充当负载来提高变频增益且增大输出电压的范围.电路采用JAZZ 0.18 μm 1P6M混合信号CMOS工艺实现,芯片版图面积1.01 mm×0.89 mm.后仿真结果表明,与以前相关电路相比,该电路的线性度有明显的改善:输入1 dB压缩点为2.48 dBm,变频增益为0 dB,1.8 V供电时的静态工作电流为32.5 mA.     

应用于SC-UWB收发机的CMOS射频接收前端电路设计

设计了应用于单载波超宽带（SC-UWB）无线收发机中的CMOS射频接收前端电路. 该前端电路采用直接变频结构,包含一个差分低噪声放大器（LNA）、一个正交混频器和两个中频放大器。其中,LNA采用源级电感负反馈结构.首先给出了该类型LNA中输入匹配带宽关于栅源电容、工作频率及匹配目标值的表达式 然后考虑到栅极片上电感、键合电感及其精度,提出了在增益和功耗约束下的噪声因子优化策略。该LNA利用两级放大级的不同谐振点实现了7.1~8.1GHz频段上的平坦增益,并具有两种增益模式来改善接收机动态范围. 正交混频器采用折叠式双平衡吉尔伯特结构. 该射频前端电路采用TSMC0.18um RF CMOS工艺设计,芯片面积为1.43 mm2. 在高、低增益模式下,测得的最大转换增益分别为42dB和22dB,输入1dB压缩点为-40dBm和-20dBm,S11低于-18dB和-14.5dB,中频3dB带宽大于500MHz. 高增益模式下双边带噪声因子为4.7dB. 整个电路在1.8V供电电压下功耗为65mW。     

2.4 GHz CMOS低噪声放大器的设计

设计了一个共源-共源共栅的两级低噪声放大器,并且在两级之间采用了串联谐振回路来提高电路的性能.该电路采用TSMC 0.18μm CMOS工艺,电源电压为1.8 V.仿真结果显示,在2.45 GHz的中心频率上,该电路能够提供26.92 dB的正向增益及很好的输入输出匹配,噪声系数为0.88 dB,功耗为14.49 mW,1dB压缩点为-9dBm.     

具有高可调增益范围的CMOS宽带中频调制器

利用TSMC 0 .2 5 μmCMOS混合工艺 ,针对超外差结构的无线宽带收发器 ,实现了一个能够工作在 5 0～6 0 0MHz的中频调制器 ,并对该调制器进行了仿真和测试。由于该调制器在输出端采用了一个具有高可调增益范围而且鲁棒性能好的可变增益放大器 (VGA) ,从而使得该调制器具有超过 70dB的增益可调范围。测试结果表明 ,该调制器能够工作在 5 0～ 6 0 0MHz的频率上 ,输出功率为 - 81～ - 10dBm ,最小增益的输出噪声为 - 130dBm/ Hz,最大增益的输出P1dB点为 - 4 .3dBm ,在 3V的电源电压下 ,电流功耗为 32mA。     

OFDM超宽带3.1-4.8GHz CMOS发射机设计

本文介绍一种应用于3.1-4.8GHz 多频带正交频分复用超宽带系统的低功耗射频CMOS发射机芯片的设计和实现。发射机系统主要由电压电流跨导级、正交上变频调制器、有源双转单转换器、输出增益可控功率放大器以及产生正交差分LO信号的除2除法器等模块组成。使用上调制器,双转单及输出放大器分段谐振技术解决3.1-4.8GHz宽带增益平坦度问题;使用源级电阻负反馈镜像跨导解决系统低电压高线性度问题;使用无源电感谐振双转单电路及增益可控放大器进行低功耗设计。测试结果表明,芯片能够提供-10.7到-3.1dBm的功率输出,并且在子带增益平坦度低于3dB;输出三阶交调量最高可达12dBm;不低于30dBc的载波抑制和35dBc以上的边带抑制。芯片采用Jazz 0.18μm射频CMOS工艺流片,包括ESD防护PAD在内芯片总面积为1.74mm2。 在1.8V的电源电压下,芯片总电流为32mA。     

应用于IEEE 802.11b无线局域网系统的2.4GHzCMOS单片收发机射频前端

实现了一个应用于IEEE 802.11b无线局域网系统的2.4GHz CMOS单片收发机射频前端,它的接收机和发射机都采用了性能优良的超外差结构.该射频前端由五个模块组成:低噪声放大器、下变频器、上变频器、末前级和LO缓冲器.除了下变频器的输出采用了开漏级输出外,各模块的输入、输出端都在片匹配到50Ω.该射频前端已经采用0.18μm CMOS工艺实现.当低噪声放大器和下变频器直接级联时,测量到的噪声系数约为5.2dB,功率增益为12.5dB,输入1dB压缩点约为-18dBm,输入三阶交调点约为-7dBm.当上变频器和末前级直接级联时,测量到的噪声系数约为12.4dB,功率增益约为23.8dB,输出1dB压缩点约为1.5dBm,输出三阶交调点约为16dBm.接收机射频前端和发射机射频前端都采用1.8V电源,消耗的电流分别为13.6和27.6mA.     

2.45 GHz有源标签接收机中的下变频混频器

设计了一种用于2.45 GHz有源标签接收机的低中频正交下变频混频器。改进了传统的吉尔伯特结构, 采用了共享跨导正交结构和电流注入技术, 以提高混频器的增益, 减小混频器的噪声。该混频器采用UMC 0.18 μm CMOS工艺设计。仿真结果表明, 该混频器在1.8 V电压下, 电流消耗为3.1 mA, 转换增益为17.18 dB, 输入1 dB压缩点Pin-1dB与输入3阶截点IIP3分别为-13.5 dBm, -3.23 dBm, 在2 MHz中频下的噪声系数为14 dB。     

OFDM超宽带3.1-4.8GHz CMOS射频收发机设计

本文介绍一种应用于3.1-4.8GHz 多频带正交频分复用超宽带系统的CMOS射频收发机芯片的设计和实现。射频收发机采用零中频结构,主要模块包括：增益可控的宽带低噪声放大器、正交跨导复用下变频混频器、5阶Gm-C切比雪夫低通滤波器及可变增益放大器;采用多项滤波器进行边带杂散抑制的快速跳变频率综合器;宽带线性上变频正交调制器、片内有源双转单电路及输出可变增益放大器。芯片测试结果表明,接收机最大能够获得68dB的电压增益,其中42dB为可变增益,增益步长为6dB;在三个子带内的噪声系数为5.5~8.8dB;带内IIP3和带外IIP3不低于-4dBm和9dBm;发射机能够提供-10.7~-3dBm的输出功率,7.7dB的增益可控;输出1dB压缩点不低于-7.7dBm;发射信号边带抑制为32.4dBc,载波泄漏抑制可达31.1dBc;频率综合器的快速跳边时间低于2.05nS。芯片采用Jazz 0.18μm射频CMOS工艺流片,包括ESD防护PAD在内芯片总面积为6.1mm2;在1.8V的电源电压下,整个芯片的工作电流为221mA (RX+TX+SYN+Buffers）。     

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.