具有陷波特性梯形印制单极超宽带天线

设计了带三角形槽梯形辐射元和阶梯接地面的30 mm×30 mm印制单极超宽带天线原型.实验结果表明,原型天线驻波比小于2的阻抗带宽为2.8 GHz～12.81 GHz,频带内天线具有全向辐射特性,增益变化平坦,相位中心稳定.通过对原型天线振子体的缝隙加载,实现了具有带阻特性的陷波超宽带天线,其驻波比大于3的陷波频带为4.8 GHz～6.0 GHz,陷波频带内最高增益抑制为9 dB,而其他频段性能与原型天线基本一致.     

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。     

一种采用微带馈电的陷波超宽带天线的设计

提出了一种改进的贴片超宽带天线。所设计的天线的是印刷在35mm＊35mm＊1mm的FR-4介质基板上。采用微带线馈电,通过将传统的矩形贴片改进为多边环形辐射单元,并且为了拓宽宽带特性,在接地板上刻蚀出一个凹形槽,使其满足超宽带系统（3.1～10.6GHz）的带宽要求。同时为了避免无线局域网（WLAN）的干扰,利用开路微带线来使天线具有陷波特性。采用高频结果仿真软件HFSS对天线进行仿真,结果表明该天线在超宽带频带范围内的回波损耗小于-10dB,同时实现了所需频带的陷波特性。     

一种采用组合陷波结构的新型超宽带平面天线

首先提出了一种小型平面超宽带天线的设计。天线采用FR4印刷电路板制作,由共面 的叉形辐射单元和多边形缝隙构成,整体尺寸为30 mm×28 mm×0.8 mm。采用 HFSS软件对天线进行了优化设计和参数分析。然后,通过在叉形辐射单元增加微带开路枝节 并且在地板开一对倒L形细裂缝的办法,设计了组合陷波结构的超宽带天线。实验表明：组 合陷波结构天线在51～5.9 GHz阻带内,回波损耗的最大值达-1.5 dB,与常规的 单陷波结构超宽带平面天线相比较,其回波损耗频率曲线更为陡峭,从而能更有效地提高 超宽带通信系统抑制无线局域网设备所带来干扰的能力。     

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。     

新型小尺寸双陷波超宽带天线设计

给出了一种小型化具有双陷波特性的超宽带天线的设计方法,采用层叠加载缝隙方式,减小了天线结构尺寸.使用微波仿真软件HFSS对天线的结构尺寸进行了分析和优化,对回波损耗,驻波比和辐射图进行了研究.分析结果表明,在超宽带非陷波频段,回波损耗不大于-10dB,有稳定的方向图;在3.3~3.8GHz和5.0~5.9GHz陷波频段,回波损耗平均有7dB的增长,产生了很好的陷波抑制作用,避免了在重叠频段系统信号的互干扰,提高了天线系统性能.     

具有高隔离度的紧凑型三陷波UWB-MIMO天线设计

提出了一种具有高隔离度的紧凑型三陷波超宽带（ultra-wideband, UWB）多输入多输出（multiple-input multiple-output, MIMO）天线,整体尺寸为38 mm×26 mm×1.2 mm.通过对辐射贴片底部两侧进行多切角,实现了宽带化;通过在接地板上加载改进的波纹T型去耦结构,并刻蚀倒“π”型槽缝隙,实现了较高隔离度;通过在辐射贴片上刻蚀“U”型缝隙、在馈线上刻蚀类“H”型缝隙以及在右侧引入倒“C”型寄生枝节,实现了WiMAX(3.3～3.6 GHz)、WLAN(5.15～5.85 GHz)和X波段（7.25～7.75 GHz）3个频段的陷波.仿真与测试结果表明,该天线工作频段为2.9～11.3 GHz（相对带宽达到118.31%）,隔离度小于-22.6 dB,包络相关系数小于0.01,辐射效率高,辐射特性良好,可以广泛应用于无线通信系统领域中.     

一种双陷波超宽带马蹄形天线的设计

提出了一种新型的带有3.4 GHz和5.5 GHz双陷波特性的超宽带天线。天线由马蹄形的辐射贴片和共面波导馈电的传输线组成。回波损耗＜-10 dB的阻抗带宽是3.1~10.6 GHz,除了其中3.3~3.7 GHz 的WiMAX和5.15~5.825 GHz 的WLAN两个陷波频段。这些陷波的频段可以通过在天线的辐射贴片上增加长条裂缝和U型缝隙来保证。加工和测试的结果表明,天线有着良好的阻抗带宽和全向辐射方向图。     

一种具有三陷波特性的超宽带印刷天线设计

提出了一种新型的具有三陷波特性的超宽带印刷天线。大钱形的辐射贴片和共面波导传输线馈电,可以保证在相当宽的3个频带内具有良好的阻抗匹配。回波损耗S₁₁＜-10 dB的阻抗带宽是3.1~10.6 GHz,除了其中3.3~3.7 GHz 的WiMAX,5.15~5.825 GHz的WLAN和7.25~8.4 GHz的X波段下行频段3个陷波频段。这些陷波的频段可以通过在天线的辐射贴片上增加长条裂缝和U形缝隙实现。加工和测试结果表明,该天线具有很好的阻抗带宽和全向辐射方向图。     

具有双频陷波特性的超宽带印刷天线研究*

通过在超宽带印刷单极子天线上开设不同形状和尺寸的缝隙,设计了一种由共面波导馈电的,具有双频陷波特性的超宽带天线.并且通过对天线仿真结果的分析,总结出了缝隙结构参数对天线陷波特性的影响规律.仿真和实测结果表明,除陷波频带外,天线在3.1到10.6GHz频带上的VSWR小于2,在3.4-3.77GHz和4.91-5.87GHz频段上具有良好的陷波特性,较好地避免了系统与WiMAX及WLAN之间的干扰.在非陷波频段上天线具有较好的全向辐射特性.此外,通过对天线表面电流分布情况的详细分析,推导出了天线的等效电路结构.     

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.