一种新型超宽带带通滤波器的设计

针对超宽带(UWB)系统易受无线网络信号干扰及传统的超宽带带通滤波器阻带较窄,不能有效抑制谐波的问题,提出了一种新型的UWB带通滤波器,该滤波器由两级交指梳状耦合谐振器级联组成,通过增加耦合指的个数来实现陷波特性,然后在两个交指谐振器的中间添加一个槽线锥形谐振器,使该滤波器具有抑制高次谐波特性,达到拓宽高阻带的效果,同时由于槽线谐振器的加入,陷波频段的抑制电平进一步提高.实验结果证明,所设计的滤波器既能保证3.1～10.6 GHz频段内的插入损耗小于3 dB,陷波频段为5.7～5.8 GHz,陷波频段的抑制电平高达-43 dB,同时又能拓宽高频阻带.     

具有陷波特性的超宽带带通滤波器设计

提出了一种超宽带微带带通滤波器。该滤波器结构简单,仅由单级平行耦合线和两个对称的1/4波长的短路截线构成。连接至平行耦合线两端的短路截线在通带两端各产生一个衰减极点,增强了该超宽带滤波器的选择性。为了消除无线网络的干扰,在提出的滤波器结构上添加开路短截线,使该滤波器具有通带内陷波特性。利用电磁仿真软件进行优化仿真,本文设计的超宽带带通滤波器的通带范围为3.1~10.6 GHz,插入损耗小于1 dB,陷波频段为5.8~5.9 GHz,陷波深度达到–40 dB。     

基于耦合线加载开路枝节的宽带带阻滤波器设计

基于单端接地耦合线结合微带传输线加载开路枝节,提出了一款宽带带阻滤波器。该滤波器由输入输出端的单端接地耦合线并联微带传输线上加载三个开路枝节组成。采用奇偶模理论分析、传输线模型和结构模型仿真优化,对滤波器的特性开展了研究。实物加工测试结果与仿真结果的一致性好,验证了所设计的宽带带阻滤波器。该滤波器的阻带中心频率为2 GHz, 3 dB衰减带宽为98%(1.19～3.15 GHz),20 dB衰减带宽为84.5%(1.24～2.93 GHz),阻带带内抑制大于35 dB,结构紧凑,可与航电系统设备板级电路集成,用于电磁干扰防护。     

一个紧凑型超宽带微带带通滤波器

设计制作了一种紧凑型超宽带微带带通滤波器。该滤波器采用两对由1/4波长型SIR谐振器和1/4波长终端短路谐振器构成的枝节线对与微带低通滤波器相联而成。在ADS软件上对该滤波器进行仿真验证,然后制作实物。结果表明,该滤波器相对带宽达到112%,阻带带宽超过4 GHz,通带范围内插入损耗小于1 d B,回波损耗大于10 d B,阻带范围回波损耗大于20 d B;滤波器尺寸为14.22 mm×9.65 mm。     

基于平行耦合微带线和DGS结构的超宽带滤波器

提出一种应用于超宽带通信且结构紧凑的平面微带带通滤波器,通带范围为3.1～10.6 GHz,带内插损小于1 dB,群延时为0.2～0.6 ns,高于10 dB的带外抑制.超宽带的带宽通过在耦合微带线正下方底面加载缺陷地结构(DGS)实现;分别在耦合线上加载折叠的阶跃阻抗枝节和DGS上附加2条槽线,在通带的低频和高频边沿产生2个传输零点,以获得较好的频带选择性与良好的带外抑制.在实验误差允许下,仿真和测量结果较一致.     

基于方开环谐振器的双陷波超宽带滤波器

针对超宽带系统易受窄带信号干扰的问题,设计了一种可以抑制无线局域网络(WLAN)和卫星通信信号干扰的双陷波超宽带带通滤波器。该滤波器的主要谐振结构由T型枝节加载的多模谐振器组成,改进的T型枝节增加了两个传输零点,同时减小了滤波器尺寸;通过耦合方开环谐振器,实现了两个陷波特性,调节谐振器尺寸,可以得到所需的陷波频率。测试结果表明,该滤波器的尺寸仅16.7mm×8.5mm,中心频率为6.9GHz,通带为3.0~10.8GHz,陷波中心频率在5.8GHz和8.04GHz,衰减最低点分别为-27dB和-18dB,仿真与测量结果有较好的一致性。     

基于CPW-微带过渡的超宽带滤波器

通过加载枝节,改进了基于CPW-微带过渡结构的超宽带带通滤波器。在微带线的中间采用了一个T型枝节以增强其选择性。该T型枝节能够在通带的上下边缘分别产生两个传输零点(2 GHz 与14 GHz)。此外,通过扇形开路枝节引入一个传输零点,将滤波器的上阻带延伸到了16 GHz。最后,加工并测试了一个滤波器用于验证。测试结果表明:该滤波器能够实现131% (2. 6 GHz ~12. 5 GHz)的相对带宽;同时,实测结果和仿真基本一致。     

基于E型谐振器的三陷波超宽带带通滤波器

针对超宽带系统中存在窄带信号干扰的问题,提出了一种加载E型谐振器的多模谐振器(Multimode Resonator,MMR)结构,采用内嵌开路枝节的方法设计了一款三陷波超宽带滤波器,并且通过调节内嵌开路枝节的长短,实现了双陷波的性能。该超宽带带通滤波器通带频带范围为3. 1~10. 2 GHz,通带内插入损耗小于1 d B,相对带宽为107%。其中,实现的三陷波滤波器的三个陷波中心频率分别为3. 8,5. 1和6. 6 GHz。通过调节内嵌开路枝节的长短,可以实现双陷波到三陷波之间的转换,仿真结果与理论分析一致。     

一种超宽阻带微带低通滤波器的设计

基于传统阶跃阻抗滤波器,提出了一种易于实现的超宽阻带微带低通滤波器改进设计方案。低阻抗线部分采用扇形微带结构,在同等阶数下,该结构的滤波器与传统阶跃阻抗滤波器相比,具有更紧凑的电路结构以及更好的阻带特性。在滤波器末端并联开路短截线,使得阻带增加额外传输陷波点来抑制寄生通带。利用ADS和HFSS仿真软件对滤波器结构进行优化设计,并进行了实物的加工和测试。实测结果表明,通带3 dB 截止频率为2 GHz,通带内0-1.8 GHz 回波损耗大于20 dB,3-20 GHz 频率范围内的阻带抑制能达到25 dB 以上。     

一种新型超宽带带通滤波器的设计与实现

传统的超宽带带通滤波器阻带较窄,不能有效抑制谐波.为了抑制超宽带系统中的高次谐波,进一步提高接收机的灵敏度,在分析叉指谐振器、半圆型缺陷地结构和阶梯阻抗并联枝节结构的基础上,设计了一种新颖的超宽带带通滤波器,该滤波器具有较好的阻带特性.最后使用Agilent N5230A矢量网络分析仪对其进行测试,测试结果表明该滤波器工作频带为3.1～10.6GHz,通带内插损小于1.5dB,上阻带的工作频率可以超过18GHz,抑制电平达到-10dB,能有效抑制谐波.     

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.