紧凑型多陷波超宽带天线设计与研究

提出了一款紧凑型多陷波特性超宽带天线,该天线由圆形贴片和改进的接地板组成。采用在辐射贴片上开两个圆弧状U形槽和接地板上开一个U形窄缝隙的结构使其具有多陷波特性。天线的体积仅为32 mm′25 mm′1.6 mm,结构紧凑。仿真与测试结果表明:该天线工作带宽为2.8 ~ 16 GHz,实现了3.2~3.8 GHz、4.5~5.5 GHz 和7.2~8.6 GHz 3个频段的陷波特性,有效阻隔了WiMAX(3.3~ 3.6 GHz)、大容量微波通信频段(4.5~5 GHz)、部分WLAN(5.1~5.35 GHz)、X波段(7.25~7.75 GHz)和国际电信联盟(ITU)波段(8.01~8.5 GHz)窄带信号的干扰。除陷波频段外该天线具有良好性能和辐射方向性,更适合应用于超宽带系统。     

一种新颖的双陷波超宽带天线设计

针对超宽带系统易受窄带信号干扰的问题,设计了一种新颖的基于金属开口谐振环结构的双陷波平面超宽带天线。通过在天线的辐射贴片上加载U形槽和在接地板上引入寄生条带的方法实现了双陷波特性。利用仿真软件研究了U形槽和寄生条带的物理尺寸对陷波特性的影响,并对所设计的超宽带天线进行了制作和测量。仿真和测试结果表明,天线在超宽带系统3.1～10.6GHz工作频段内的电压驻波比小于2,在WiMAX和WLAN频率范围具有良好的陷波特性,有效地抑制了超宽带通信系统与窄带通信系统之间潜在的干扰。     

一种共面波导馈电的双陷波渐变槽天线

为了滤除WIMAX(3.3～3.8 GHz)和WLAN(5.125～5.825 GHz)窄带信号对超宽带系统的干扰,该文提出一款共面波导馈电的小型化双陷波渐变槽天线。共面波导结构可以有效地扩展天线的带宽,实现对整个UWB(3.1～10.6 GHz)频段的全覆盖。通过在天线的馈线上开L型缝隙和在辐射贴片上开一对E字型缝隙的方法,有效实现了在3.15～3.97 GHz和4.94～6.05 GHz频段的双陷波特性,能够抑制WIMAX和WLAN对超宽带系统的干扰。该天线结构简单紧凑,尺寸非常小,仅为40 mm×18 mm×0.813 mm。仿真和实测结果表明该天线在超宽带波段内具有良好的陷波特性、增益特性,可以应用于小型化超宽带系统中。文中方法对于陷波渐变槽天线的研究具有一定的借鉴意义。     

一种双陷波超宽带天线设计与研究

为了避免如WiMax和WLAN等窄带通信系统对超宽带通信系统的影响,该文提出一种具有双陷波特性的超宽带天线。该天线采用圆形贴片作为辐射单元,通过在贴片和接地板上分别开圆弧状的H形槽和L形槽来实现双陷波特性。天线在3.1~10.6 GHz的超宽带频段内能够有效地工作并抑制两种不同的窄带通信系统的干扰。同时圆弧状H形槽的参数研究表明,这种开槽结构能够以槽参数组合的形式更有效地控制陷波中心频率。实测和仿真结果吻合,该天线实现了良好的陷波功能,在工作频段内有良好的辐射方向特性。     

毫米波宽带双陷波MIMO天线设计

为有效抑制部分毫米波通信信号干扰,实现无线通信设备小型化,设计了一款具有双陷波特性的毫米波宽带MIMO天线。天线基本单元由辐射单元、微带馈线、Rogers RO4350B基板以及接地板构成。通过在天线辐射贴片刻蚀U型槽,以及接地板添加倒U型枝节,可在工作频段内产生双陷波特性;进一步在接地板引入圆形开槽使MIMO天线获得良好的隔离度。该天线结构紧凑,尺寸仅为26.7 mm×16.67 mm×1.524 mm,工作于21～40 GHz频段,其中陷波频段为22.04～24.72 GHz和25.96～31.2 GHz。结果表明：该天线在工作频段内隔离度大于20 dB,最大增益可达8.49 dBi,包络相关系数(ECC)均小于0.002,具有良好的辐射和增益性能,在毫米波超宽带通信中具有应用潜力。     

一种具有三阻带特性的超宽带天线的设计与研究*

提出了一种紧凑型共面波导馈电的具有三阻带特性的超宽带天线。所设计天线的基本几何结构由共面波导(CPW)馈电线、菱形辐射贴片和矩形宽缝隙组成。通过在辐射贴片上刻蚀一个U型槽,以及在共面波导的接地面上增加两对L型的寄生旁枝结构来实现天线的三陷波特性。天线尺寸为32mm×32mm×0.508mm。仿真和实验结果表明,该天线在2.6~11.5GHz的频段内电压驻波比小于2,在3.15~3.80GHz、5.20~5.80GHz和8.2~8.7GHz三个频段内具有陷波特性,分别有效阻隔了Wi MAX系统、WLAN系统和ITU 8GHz频段信号对于超宽带(UWB)系统的干扰。在除三个阻带频段外的其余UWB工作频段范围内,具有良好的辐射方向特性和稳定的增益。仿真结果和实验结果表现出良好的一致性。     

具有双陷波特性的蜂窝结构分形超宽带天线

提出了一款具有双陷波特性的蜂窝结构分形超宽带（ultra-wideband，UWB）天线，采用二阶蜂窝结构作为辐射贴片和缺陷地结构接地板实现良好的超宽带特性.通过在辐射贴片上挖去正六边形和矩形宽缝隙并引入对称鱼钩形枝节，在馈线处刻蚀倒U形窄缝隙产生了3.27~4.27 GHz和7.2~8 GHz两个频段的陷波特性.天线在2.8~11.6 GHz的频段内，可有效抑制WiMAX、C波段卫星和X波段卫星窄带系统的干扰.仿真和实测结果基本吻合，表明该天线适合应用于各种UWB通信系统.     

一种可控三陷波超宽带天线设计与研究

为了避免如WiMax, WLAN和X频段卫星系统等窄带通信系统对超宽带通信系统的影响,该文提出一种具有可控三陷波特性的超宽带天线。该天线通过在辐射贴片和接地板上开槽,并在基板背面增加环形寄生单元的方法实现三陷波特性。天线在3.1~10.6 GHz的超宽带频段内能够有效地工作并抑制3种不同的窄带通信系统的干扰。同时在环形寄生单元处增加开关设置,使天线能够实现双/三陷波的功能切换,并增强陷波性能。实测和仿真结果吻合,该天线实现了良好的陷波功能,在工作频段内有良好的辐射方向特性。     

共面波导馈电的三陷波超宽带天线的设计

设计了一种共面波导馈电的三陷波超宽带天线。所设计的天线尺寸为30mm×30mm×1.8mm,印刷在介电常数为4.4的FR4介质基板上。通过分别在辐射贴片上加载"哑铃"型缝隙和在共面馈线上加载不对称"U"型缝隙以及共面地板上加载矩形缝隙来实现三陷波特性。利用高频仿真软件HFSS进行仿真、分析和优化,最终实现天线在2.20～11.82GHz的频段内,除了在3.52～3.80GHz、4.60～5.60GHz和7.62～8.30GHz具有陷波特性,回波损耗大于-10dB,则其他频带回波损耗小于-10dB,且具有陷波频带可调的优点。天线能够避免分别来自WiWAX系统、WLAN系统和X波段信号的干扰,同时在超宽带(UWB)天线的通带内能实现良好的远场辐射特性。     

一种新型平面结构的双陷波超宽带天线设计

为了避免现存的一些窄带通信系统对超宽带天线的干扰,提出了一种具有双陷波特性的超宽带天线结构。由于采用了渐变式阶梯阻抗匹配结构作为超宽带基础天线的馈电,使天线具有了宽阻抗匹配能力。通过在基础天线背面附加双偏T寄生单元和在辐射贴片上开窗的联合方法,实现了超宽带天线的双陷波特性。天线电流分布结果可以完全反映出在陷波频率下两种方法的谐振抑制作用,而且实验结果表明该结构的天线对 WLAN(5.15～5.825 GHz) 和WiMAX(3.4～3.69 GHz)频段的信号起到了有效的抑制作用,同时在工作频段内表现出较好的全向辐射特性。     

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.