UHF RFID阅读器中恒定调谐增益LC-VCO设计

设计了一种应用于UHF RFID阅读器的恒定调谐增益LC-VCO。VCO采用互补交叉耦合结构实现较高电源利用效率,偏置电路采用电压调节结构有效抑制电源引入的噪声。提出创新的分布式偏置容抗管阵列,以实现恒定调谐增益。电路采用TSMC 0.18μm CMOS RF工艺设计。仿真结果表明,VCO的频率调谐范围为1.61~2.03GHz,在1MHz频偏处,相位噪声为-127dBc/Hz,电源电压1.8V,电路消耗的总电流为3.4mA。电路在保证低相位噪声和低电源噪声灵敏度的同时,工作频带内调谐增益的变化控制在±7%以内。     

一种应用于高灵敏度GNSS接收机低相位噪声Q增强型可变电容的LC压控振荡器

本文提出了一种增强型品质因素(Q)可变电容的LC压控振荡器,用于高灵敏度GNSS接收机。提出的增强的累积型MOS(A-MOS)可变电容由两个A-MOS可变电容和两个直流偏置组成,具有改善Q值和线性化电容-电压曲线的优点。数字切换的可变电容阵列（DSVA）对所有的VCO子波段进行VCO增益补偿,基于A-MOS可变电容的特性,DSVA中的可变电容关断时,其作为高Q值的固定电容,而当可变电容接入时,其作为Q值适中的调谐电容,这样保证了整个LC谐振腔的Q值最大化。提出的电路已经在0.18 1P6M的CMOS工艺上制造。测量的相位噪声低于-122dBc/Hz当偏移频率为1MHz, 通过调节子波段和控制电压,测得的调节范围为58.2%,而VCO增益变化小于?21%。当采用1.8V电源电压时,提出的压控振荡器在整个工作范围内功耗小于5.4mW.     

UHF RFID阅读器中恒定调谐增益LC-VCO设计

设计了一种应用于UHF RFID阅读器的恒定调谐增益LC-VCO。VCO采用互补交叉耦合结构实现较高电源利用效率,偏置电路采用电压调节结构有效抑制电源引入的噪声。提出创新的分布式偏置容抗管阵列,以实现恒定调谐增益。电路采用TSMC 0.18 μm CMOS RF工艺设计。仿真结果表明,VCO的频率调谐范围为1.61～2.03 GHz,在1 MHz频偏处,相位噪声为-127 dBc/Hz,电源电压1.8 V,电路消耗的总电流为3.4 mA。电路在保证低相位噪声和低电源噪声灵敏度的同时,工作频带内调谐增益的变化控制在±7%以内。     

一种新型CMOS电流反馈运算放大器的分析与设计

通过加入对电源电压不灵敏的基准源产生偏置电流,采用MOS管产生的电阻和MOS管电容串联的补偿结构,消除补偿电容带来的零点;并在输出端采用电阻反馈,降低了输出电阻,增强了带负载能力.在1.5 V电压下,偏置约为1 μA.基于BSM3 0.5 μm CMOS工艺,对电路进行了PSPICE仿真.负载为20 pF时,该电路获得了87 dB的开环增益,353 MHz的单位增益带宽,61°的相位裕度和132 dB的共模抑制比,功耗为1.24 mW.     

11GHz CMOS环形压控振荡器设计

设计了一种全差分高速环形压控振荡器（VCO）．该VCO有三级,每一级的增益是快慢通路增益的矢量叠加和,快慢通路的增益由底部电流源决定,差分控制电压通过镜像电流源控制快慢通路的各自电流,最终实现对振荡频率的调节．分析了VCO的工作原理及其相位噪声．电路采用TSMC公司0.18μm标准CMOS工艺制作．测试结果显示：芯片工作频率为10.88～11.72GHz,相位噪声为－101dBc/Hz@10MHz,输出信号抖动为3.8ps rms,在1.8V电源电压下的直流功耗约为75mW．该VCO可以应用于锁相环和频率合成器中．     

1．3～2．2 GHz低噪声低功耗 CMOS LC VCO的设计

基于TSMC 0．18μm RFCMOS工艺,设计并实现了一个宽带低功耗低相位噪声的高性能压控振荡器（VCO）．为实现1．3～2．2 GHz调谐范围,VCO采用7‐bit（128根调谐曲线）固定电容阵列,同时也获得了超低的增益,降低了相位噪声．为弱化宽调谐范围带来的增益波动,VCO采用3‐bit可变电容阵列来提升低带曲线的斜率,以期与高带一致．为实现每根曲线的宽线性范围,可变电容采用分布式偏置电压技术．为降低相位噪声,还提出了一种输出零偏置架构以及电流源噪声滤除技术．测试结果表明,调谐电压的线性范围为0．2～1．6 V ;VCO输出频率范围为1．3～2．17 GHz ;高带调谐曲线叠合超过50％,低带超过80％;VCO增益仅为19 M Hz／V ;增益波动范围为13～25 M Hz／V ．当振荡频率为1312 M Hz ,1 M Hz 频偏处相位噪声为－116．53 dBc／Hz ;当振荡频率为2152 M Hz ,1 M Hz频偏处相噪为－112．78 dBc／Hz ．VCO功耗电流为1．2～3．2 mA ,电源电压为1．8 V ．提出的VCO既能提供51％的频率覆盖,又能实现低相位噪声,已经被成功应用于工业自动化无线传感网（WIA ）射频收发机芯片中．     

11GHz CMOS环形压控振荡器设计

设计了一种全差分高速环形压控振荡器(VCO).该VCO有三级,每一级的增益是快慢通路增益的矢量叠加和,快慢通路的增益由底部电流源决定,差分控制电压通过镜像电流源控制快慢通路的各自电流,最终实现对振荡频率的调节.分析了VCO的工作原理及其相位噪声.电路采用TSMC公司0.18μm标准CMOS工艺制作.测试结果显示:芯片工作频率为10.88～11.72GHz,相位噪声为-101dBc/Hz@10MHz,输出信号抖动为3.8ps rms,在1.8V电源电压下的直流功耗约为75mW.该VCO可以应用于锁相环和频率合成器中.     

基于CMOS工艺宽带LC压控振荡器研究

设计了一种应用于无线通信系统的宽带电感电容(LC)压控振荡器(VCO),电路采用开关电容阵列获得了宽频率覆盖范围;利用开关可变电容阵列减小了调谐增益变化;并通过采用高品质因数的差分电感和噪声滤波技术获得了低相位噪声.电路设计采用SMIC 0.18 μm CMOS工艺.仿真结果表明:在工作电压为1.8 V时,直流功耗为9 mW,压控振荡器的频率范围870～1500 MHz(53%),调谐增益在67 MHz/V至72 MHz/V之间.相位噪声优于-100 dBc/Hz@100 kHz.     

一种面向IEEE 802.11ac标准的5 GHz LC压控振荡器

基于TSMC RF 0.18 μm CMOS工艺,设计了一种可应用于IEEE 802.11ac标准的5 GHz宽带LC压控振荡器。该振荡器采用了NMOS交叉耦合结构,同时采用了5位开关电容阵列以扩展调谐范围。开关电容阵列使压控振荡器的增益KVCO保持在一个较小的值,有效地降低了压控振荡器的相位噪声。后仿真结果表明,该压控振荡器在1.8 V电源电压下,功耗为9 mW,频率调谐范围为4.52~5.56 GHz,在偏离中心频率1 MHz处仿真得到的相位噪声为-124 dBc/Hz。该LC 压控振荡器的版图尺寸为320 μm×466 μm。     

一种宽频带CMOS高速锁相环

基于55 nm CMOS工艺,设计了一种宽频带高速锁相环(PLL)。PLL中的压控振荡器(VCO)采用8位开关电容阵列和变容管阵列,实现了对VCO振荡频率的调节和不同频段之间的切换。VCO采用分段式结构,实现了8.7~12.5 GHz的宽频率范围。分段结构中,每个频段的频率增益Kvco较低,实现了良好的相位噪声性能。仿真结果表明,在1.2 V电源电压下,该PLL的最高工作频率为12.5 GHz,锁定时间为小于2.5 μs,相位噪声为-106 dBc·Hz-1@1 MHz。     

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.