平行耦合微带线带通滤波器分析与设计

为了克服平行耦合微带线带通滤波器设计中存在的尺寸大、需要查表、优化困难等问题,提出了一种平行耦合微带线带通滤波器基于ADS软件的设计方法。经过深入的理论分析发现,平行耦合线带通滤波器系统阻抗微带线非谐振单元,长度可尽量取短以减小电路尺寸;利用ADS软件自带滤波器设计工具可得到低通滤波器原型,省去了查表的麻烦;在版图优化上采用调谐方法比优化方法更有效。仿真结果表明,所设计带通滤波器系统阻抗微带线为2.5 mm,中心频率5 GHz,相对带宽10%。该方法在减小滤波器尺寸的同时没有降低滤波器性能,设计实现快速高效。     

平行耦合微带线带通滤波器的设计与优化

平行耦合微带线带通滤波器在微波电路系统中广泛应用。为了提高带通滤波器性能,缩短设计周期,采用奇偶模原理分析与ADS(Advanced Design System)仿真相结合的方法,设计出一个中心频率为2.5 GHz,相对带宽为10%的平行耦合微带线带通滤波器。进一步优化参数,得到电路版图。最终结果证明,这种方法具有设计周期短、可靠性高的特点,且各项参数满足设计要求。     

基于ADS的平行耦合带通滤波器的设计

文中介绍了设计平行耦合带通滤波器的方法和流程,以相对带宽为9%的平行耦合滤波器为例阐述了具体设计过程,并对滤波器设计工程中原理图与版图仿真结果的差异进行分析对比,给出具体的调试解决方案.借助于射频微波EDA工具ADS2008进行优化仿真.高效地完成了带通滤波器的设计,达到了设计要求.     

平行耦合微带线带通滤波器的研究与设计

由于其优越的性能,微带线形式的各种滤波器已成为广泛使用的射频器件.本文重点研究平行耦合微带线带通滤波器的原理和设计方法,并且对其不足之处,提出了全等宽平行耦舍微带线带通滤波器的设计思路.最后,结合具体应用实例,通过仿真计算,对两种形式的滤波器进行比较.结果表明全等宽平行耦合微带线带通滤波器适用带宽较宽,且结构简洁,大大降低了设计及仿真调试的复杂度.     

基于并联耦合线谐振节的窄带带通滤波器的研究

设计了一种基于并联耦合线谐振节的窄带带通滤波器。该滤波器由常见平行耦合线带通滤波器与并联耦合线谐振节构成。利用并联耦合线谐振节结构的特性,借助ADS软件设计了一个中心频率为4.9 GHz的窄带带通滤波器。仿真结果表明,其3 dB带宽为236 MHz,矩形系数为2.8。该滤波器具有良好的带外抑制能力和更加陡峭的通带到阻带过渡。     

基于耦合线的紧凑型巴伦带通滤波器设计北大核心CSCD

本文利用发卡滤波器和耦合线组合电路，提出了一款新型巴伦带通滤波器，其具有结构紧凑、简单及集成度高等优点。文中分析了三阶发卡滤波器原理和耦合线组合电路（即平行耦合线和终端短路反平行耦合线）输出180°相位差特性，将二者组合成巴伦带通滤波器，避免了传统巴伦带通滤波器在各路加载滤波器而造成整体系统结构尺寸偏大的问题。所设计的巴伦带通滤波器工作中心频率为2 GHz，实测3-dB带宽为6%，带内插入损耗为4.58 dB，相位差为180°±3.1°，幅度差为0 dB±0.29 dB。仿真和实测结果吻合良好，证明了该设计的可行性。     

基于ADS的Ka波段平行耦合带通滤波器的设计

文中先是介绍了平行耦合带通滤波器的设计方法和流程,然后以中心频率为33G的平行耦合带通滤波器为例,具体说明了设计及优化过程.并在此基础上生成版图,之后导入到HFSS中进行仿真验证.两次的结果均符合设计要求.本文主要是在电路原理图级进行的设计,仿真,和优化.     

平行耦合微带线带通滤波器的多步法优化设计

提出一种通过提升设计频率来解决平行耦合微带带通滤波器中边缘场效应导致的中心频率偏移的方法。同时分析了导致这种偏移的原因,并阐述了该方法的理论基础。给出的实例证明,在使用微波软件设计平行耦合微带线带通滤波器时,这种方法是简洁且可行的。     

平行耦合线滤波器

介绍了交错平行耦合带状线滤波器的设计方法及其过程,用此方法设计了7．5～18GHz的带通滤波器,使用Microwave Office软件对此滤波器进行了仿真,并对滤波器进行了安装测试。     

基于ADS仿真设计的微带带通滤波器

本文介绍了一种借助ADS2005a仿真软件设计微带带通滤波器的方法,并仿真设计出了一个平行耦合线带通滤波器。仿真结果表明:这种方法是简单可行的,并且能满足工程设计要求。     

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.