一种小型具有双阻带特性的超宽带天线设计

提出了一种具有双阻带特性的共面波导馈电超宽带天线。通过在辐射单元上开E型槽实现了3.75 GHz的第一个陷波结构,并在地板上开两条对称槽实现5.5 GHz的第二个陷波结构。文中提出的具有阻带特性超宽带天线的实测结果与仿真结果吻合较好。除了两个期望的阻带外其他超宽带频段内,该天线满足VSWR<2。同时给出了仿真辐射方向图和增益图。     

一种CPW-fed的双陷波超宽带天线的设计

设计了一种小型双阻带超宽带天线.天线采用共面波导(CPW)馈电的地板结构,地板由两个半椭圆构成,从而实现了超宽带天线及小型化.通过开双U型缝隙实现了双阻带特性,阻带带宽分剐是650 MHz和590 GHz.天线实物测量结果表明,天线驻波比<2的带宽为2.97～12.75 GHz,在整个频段内天线增益较高,同时方向图全向...     

小型化陷波超宽带天线

针对超宽带通信系统（3．1～10．6GHz）与WLAN工作频段（5．15～5．825GHz）之间存在的电磁干扰,本文提出了一种小型化陷波超宽带天线。该天线结构简单,体积较小,陷波特性良好。通过在介质板上侧的金属地板刻蚀C形槽缝可以使天线在5．15～5．825GHz频段实现良好的陷波特性,而且调节C形槽缝的长度可以调节阻带的频段。研究结果表明,该天线的辐射特性良好,能够广泛应用于超宽带通信系统。     

一种紧凑型超宽带双陷波天线设计与研究

超宽带(UWB)系统的工作频段与现有的许多窄带系统频段相互重叠,因此各个系统信号之间存在潜在的干扰。针对上述问题提出了一种紧凑型超宽带双陷波天线。天线由一个圆形辐射贴片构成并通过50W的微带线进行馈电。接地板和传统的接地板相比被截短了,以提高天线的阻抗带宽。通过在辐射贴片上刻蚀H 型槽来实现天线的双陷波功能,并在微带馈线中引入了嵌入式谐振回路(ERC)结构,加大了天线的陷波深度和阻带宽度,陷波性能好于同频段的双陷波天线。仿真和测试结果表明,天线在3.1～4.2 GHz 以及5.0～6.6GHz 具有陷波特性,有效地避免了WiMAX 和WLAN 频段信号的干扰。同时在2.8 ~10.7 GHz 的其它频段上具有良好的阻抗匹配和较好辐射方向特性。天线的尺寸为34mm*26mm*1.6 mm,结构较为紧凑。     

一种双阻带椭圆单极子UWB天线的设计

通过仿真与实际测试结合的方法,研究并设计了一种用于UWB通信的、具有双阻带特性的紧凑椭圆单极子天线。双阻带特性是通过在辐射单元上插入一个缝隙和在馈线上引入一共面波导谐振单元实现的。测试结果表明此天线在3.45~3.75 GHz(覆盖了WIMAX频段)和5~6 GHz(覆盖了5.15~5.85 GHz的WLAN频段)分别有两个阻带,此外,驻波系数在3.1~10.6 GHz UWB的范围内小于2。天线的辐射特性也近似于全向。天线的增益和传输函数也证实了天线能达到双阻带特性。     

一种小型双陷波超宽带天线的设计

设计了一种小型双阻带的超宽带天线。采用由两个半椭圆和一个长条矩形复合的一种新型地板结构,从而实现了超宽带天线小型化。通过开双U型缝隙实现了双阻带特性,阻带带宽分别是540 MHz和610 MHz。天线实物测量结果表明,天线驻波比＜2的带宽为2.7~12 GHz,在整个频段内天线增益较高,同时方向图全向特性良好。天线的测量结果和仿真结果有较好的一致性。     

一种Wi-Fi宽阻带微带天线设计

本文介绍了一种可用于Wi-Fi系统的宽阻带微带天线设计。该天线包括绝缘矩形介质基板、金属通孔、下层金属接地板及上层金属辐射模块;通过控制上层正六边形金属片的大小,金属通孔位置,以及微带线长度,从而实现特定通带并具有宽阻带特性。该天线工作在2.4GHz频段,并且-10dB阻带范围可以达到2.57GHz-17.8GHz,阻带和通带频率比可达到7.1。该天线加工成本低、易集成、易安装、性能优良,能够满足无线Wi-Fi通信系统要求。     

具有陷波特性的超宽带印刷天线设计

设计一种具有陷波特性的超宽带印刷天线,天线采用圆形金属贴片作为辐射单元,采用微带线进行馈电,通过在贴片上开四个对称T形槽来实现陷波功能。利用仿真软件HFSS10．0对其进行计算,对天线的阻抗特性、方向图和增益进行了研究。运算结果表明,该天线在2．26～4．94GHz和6～11．68GHz的工作频带范围内电压驻波比（VSWR）小于2;在4．94～6GHz的阻带范围内具有良好的陷波特性;在阻带中心频率（5．48GHz）处,电压驻波比高达40。     

具有多阻带特性的超宽带天线研究与设计

设计一种具有多阻带特性的平面超宽带天线,采用在辐射贴片开C型槽和H型槽的方法实现天线在Wi MAX频段和WLAN频段的带阻抑制特性。U型槽孔产生高于10.6 GHz的高频阻带,同时馈线终端的阶梯结构实现了多频宽带的匹配。该天线在3.16~3.73 GHz,4.63~6.02 GHz以及高于10.6 GHz的超宽带频带内形成阻带,表明其在工作频带内有良好的抗干扰能力。此外,在天线的通带内有良好的全向特性,结果表明该设计方法的有效性。     

一种高隔离度的双阻带超宽带MIMO天线设计

针对无线通信系统中的超宽带传输要求,设计了一种以FR4为基板的高隔离度的双阻带超宽带MIMO天线。天线由两个辐射单元组成,两个天线辐射单元结构相同,采用了微带馈电的馈电方式。该MIMO天线单元为U型的超宽带单极子天线,通过在天线单元上刻制两个U型槽,使得在天线的工作频率上添加了用于WiMAX和WLAN的阻带。在两个单元天线中间,引入了一条T型地板枝节作为隔离结构,用于改善MIMO天线的隔离度。经网络矢量分析仪测试结果表明,该天线覆盖在2.44～10.75 GHz,且隔离度全部低于-22 dB,拥有较高的隔离度,最大增益为6.76 dB,在实际工程应用当中可以满足UWB无线通信的要求。     

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.