一种基于键合线电感的LC-VCO设计方法

提出一种利用键合线电感设计VCO的方法,利用HFSS(High Frequency Structure Simulator)软件,建立电感仿真模型,在5 GHz以下与库模型相吻合.仿真结果表明,差分键合线电感受工艺偏差的影响小于15%,并提出一种减小互感的方式,使电感值在1～5 GHz范围内增加15%～175%.利用HFSS提取的等效电路,设计了一款输出频率为2～3.6 GHz的宽带压控振荡器(VCO),当工作在3.6 GHz时,1 MHz频偏处的相位噪声为-111 dBc/Hz,电流为1.5 mA.电路版图面积仅为0.1 mm2,较之采用片上电感的VCO(0.19 mm2),面积减小45%.     

微带芯片互联失配分析及匹配电路设计

20GHz以上,当微带衬底材料的介电常数较低(εr=2.2),而GaAs芯片的介电常数为12.9时,直接用50Ω微带互连会产生较大的反射。对微带芯片互联的失配形式进行了分析和研究,采用在微带与芯片间加一段高阻微带线的方法进行匹配互联,并针对于25~30GHz频率范围对高阻微带线宽度和长度进行仿真和优化。相对于直接互联,匹配互联的插入损耗减小了0.4dB左右,回波损耗减小了9dB以上。最后对直接互联和匹配互联分别进行实物加工装配,测试结果与仿真结果相吻合。     

倒扣焊安装的微机械毫米波介质集成波导滤波器

为了解决毫米波段滤波器因倒扣焊安装引起的性能恶化问题,本文基于MEMS技术提出了联合仿真设计方法,将MEMS介质集成波导滤波器芯片与罗杰斯介质板利用三维高频仿真软件HFSS进行共同建模设计,充分考虑两者互连时易产生的问题,完成了芯片的制作、安装、测试及结果分析。测试结果表明,该滤波器通带为41.5~42.7GHz,去嵌后通带插损小于0.8dB,通带内反射损耗优于17dB,在38GHz处带外抑制优于40dB,芯片尺寸仅为5.2mm×3.0mm×0.4mm。考虑工艺误差影响,设计与测试结果吻合良好,该方法有效改善了毫米波段滤波器频率偏移及安装互连引起反射损耗恶化等问题。     

基于二极管单平衡的微波相位检测器的模拟及设计

介绍了基于肖特基势垒二极管单平衡结构的微波相位检测原理,在分析3 dB功率分配定向耦合器的功能基础上提出了一种展开式兰格耦合器的改进结构,使得设计的精度和自由度大为提高,在8到12 GHz的频率范围内S21 和S31绝对值的差不超过0.4 dB,相位差在90o±0.5o范围内.文章进一步采用四管单平衡结构,提高了测试的精度,K达到了0.56;同时可测信号的幅值也有所增加,达到了1.5 V.     

一种基于平面螺旋电感的不平衡变压器的设计

提出了一种基于0.13μm工艺,采用平面螺旋电感结构的宽带单片不平衡变压器。该电路的中心频率为23 GHz。在中心频率附近,模拟结果显示,单端口损耗为8 dB,在20~30 GHz频率范围内,两端口信号幅度误差为1 dB,相位误差为5°。     

1.6 GHz 24位4阶Σ-Δ小数分频频率合成器

介绍了一种3 V 0.35μm BiCMOS工艺实现的1.6 GHz小数分频频率合成器。它采用新型的24位4阶Σ-Δ调制结构数字调制器,以减少频率合成器的带内相位噪声、锁定频率切换时间,在获得高达20 MHz鉴相频率的同时,能达到小于1 Hz的频率分辨率。仿真结果表明,它的锁定范围是1.615~1.675 GHz,环路带宽100 kHz,带内相位噪声低于-90 dBc/Hz,锁定频率切换时间小于25μs,可以很好地满足个人手持电话系统PHS标准的应用。该电路功耗为20 mW,芯片面积1.7 mm×0.8 mm,其中,Σ-Δ调制部分所占面积为1 mm×0.4 mm。     

超宽带平坦多载波光源结构设计

为了解决波分复用系统中传统光源稳定性差、成本高、带宽小等问题,本文提出了一种超宽带平坦光源发生器结构,该结构基于级联的电吸收调制器和两个频率调制器,得到了频率间隔相同且可调的高带宽、平坦度小的多载波光源。在单波长光信号输入下,产生了大范围频率间隔可调平坦度小于0.2 dB的21个子载波的多载波光源,当驱动信号频率为8 GHz和9 GHz时,平坦度可达到0.07 dB;在多波长光信号输入下,得到了频率间隔为15 GHz,平坦度小于0.9 dB子载波数为275的超宽带平坦光源,频谱宽度可以达到THz以上。最后研究了10 GHz驱动信号下,电吸收调制器与频率调制器驱动信号的相位差、频率调制器的频率偏移以及电吸收调制器的啁啾因子对多载波光源的影响,结果表明,驱动信号的相位差在±10°上下波动时,平坦度最大改变了1.05 dB,频率调制器的频率偏移在±10 GHz范围内变化时,平坦度波动幅度仅为0.1 dB,表明该结构具有良好的稳定性和可控性。     

一种2.4-GHz全集成双环路频率综合器的设计

根据不同锁相环频率综合器架构各自的优缺点,选择了双环路锁相环结构以获得低相位噪声和快速锁定时间。采用0.18μm CMOS工艺设计了一款2.4 GHz全集成双环路锁相环频率综合器,由主锁相环和参考锁相环环路构成。采用MATLAB和SpectreRF对锁相环系统的相位噪声、锁定时间进行了仿真,得到主锁相环输出频率为在2.4 GHz时,相位噪声为-120 dBc/Hz@1 MHz,功耗为10 mW,电源电压为1.8 V。频率范围为2.4 GHz至2.5 GHz,RMS相位误差为1°,锁定时间为5μs。     

考虑频率波动的微波加热数值模拟模型

家用微波炉内磁控管的频率会有波动,且难以测定。为考查微波频率波动对样品温度分布的影响, 获得更加精确的仿真结果,研究假设家用微波炉的频率以2. 45 GHz 为中心波动,并对不同波动范围的频率(2.44~2.46 GHz,2.43~2.47 GHz,2.41~2.49 GHz)与单个频率(2.45 GHz)的基于有限元模型的仿真结果与实验结果进行了比较分析。实验对象是放置于微波炉内加热60 s 的土豆泥。对于不同的频率范围分布,每隔0. 005 GHz 计算一次电磁功率密度,并根据余弦分布对它们进行加权平均,最后将电磁功率作为热源加热土豆泥。模拟结果分别与用热成像仪和光纤热电偶测定的土豆泥表面温度分布和各部位瞬时温度的实验值进行比较。结果显示频率波动范围在2.44~2.46 GHz 预测的温度场与实验值有较好的一致性;而在2.41~2.49 GHz 范围内,温度分布的均匀性最好。该模型也可为指导微波食品的开发提供理论依据。     

低电调电压全集成10~20GHz VCO的设计与实现

研制了一款低电调电压、多频段压控振荡器(VCO)微波单片集成电路(MMIC),MMIC主要由6频段振荡电路、控制电路、译码电路等组成。将10~20 GHz的频率范围分为6个频段覆盖,从而将电调电压控制在5 V以内。基于GaAs异质结双极晶体管(HBT) 2μm工艺对所设计的VCO进行了流片验证,芯片面积为3.4 mm×3.2 mm。测试结果表明,在室温下,当电源电压为5 V、电调电压在0~5 V时,每个频段VCO可覆盖的频率为9.58~11.6 GHz、11.06~13.23 GHz、12.77~14.89 GHz、14.21~16.48 GHz、16~18.48 GHz和17.7~20.17 GHz;当电调电压为2.5 V、频偏为100 kHz时,每个频段VCO的相位噪声分别为-91.8、-90.5、-90.3、-90、-88.2和-87.1 dBc/Hz。因此,该6频段VCO覆盖了10~20 GHz的频率范围,且每段VCO的相位噪声指标良好,可满足低压电子系统的应用需求。     

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.