SIW四极化“目”字形漏波天线

为克服传统漏波天线存在的开阻带缺点,提出了斜45°“目”字形缝隙结构,分析了该结构的色散特性和辐射特性,进而设计了具有波束从后向到前向连续扫描功能的漏波天线。同时,提出了四极化形成方案,利用 3 dB 耦合器作为圆极化馈电网络,再引入90°移相器后形成线极化馈电网络。将两条“目”字形缝隙线阵与馈电网络相结合来实现四极化漏波天线。测试结果表明,该四极化天线具有较好的端口隔离度,线极化的波束扫描范围是-25°~21°,圆极化的波束扫描范围是-21°~31°。     

漏波天线中阻带的应用及抑制

周期性结构会引入阻带.有些阻带对有些漏波天线有用,如可用于抑制某些不需要的传播模.但阻带对大部分周期性漏波天线是不利的,如边射阻带使得主波束在边射方向不能连续扫描.文中讨论了周期性结构阻带在漏波天线中的应用及抑制.给出了一个阻带应用实例:微带漏波天线一般工作于EH1模,在激励其EH1模时往往会激发不希望的EH0模,在微...     

基于人工表面等离子体激元的毫米波高扫描率四波束漏波天线

为灵活控制波束以增强多目标探测和跟踪功能，研制了基于人工表面等离子体激元（SSPP）的毫米波四波束高扫描率漏波天线（LWA）。根据正弦电抗调制叠加理论，对基片集成波导（SIW）槽缝形成的SSPP结构进行多周期性叠加调控，实现四波束扫描LWA。为改善天线的法向辐射性能，在SIW下表面周期性开槽，消除LWA的阻带效应。对设计的LWA进行加工和测试，结果表明在29 GHz～30.2 GHz的频带内，该天线的四个波束能从-52°连续扫描到+22°，扫描率达到18°/%BW，节约了频谱资源，并提高了多目标探测效率。     

基于复合左右手材料的圆柱共形漏波天线设计

提出了一种基于复合左右手材料的平衡式圆柱共形漏波天线。天线单元由圆柱共形介质波导构成,通过在波导上表面蚀刻矩形缝隙槽结构,在引入串联电容的同时实现电磁波能量的连续泄漏,从而得到所需要的辐射特性。同时在波导结构中采用金属化通孔,引入并联电感, 实现了电磁波的左手传输特性。所设计的天线在平衡频点 15.6 GHz 处具有良好的边射特性。所提出的复合左右手漏波天线的阻抗带宽为 4.3 GHz(13.5~17.8 GHz),在天线阻抗带宽范围内天线主波束可以从-57°连续扫描到+30°。     

宽带低交叉极化超材料漏波天线的设计

基于基片集成波导结构提出了一种新型双层电磁超材料单元，并验证了其左手特性。将超材料单元应用于漏波天线的设计，所设计的天线由15个双层电磁超材料单元组成。将设计好的天线进行加工测试，测试与仿真结果吻合较好，表明漏波天线的工作频带为7.20~12.70GHz，在工作频带内可实现从后向-78°到前向+80°的连续主波束扫描，天线在工作频带内的测试增益均大于10dBi，峰值增益为15.2dBi，3dB增益带宽达到50.2%。此外，该漏波天线具有很低的交叉极化电平，交叉极化始终比主极化低至少30dB。相比于新近文献报道的同类型超材料漏波天线，所设计的天线具有更加优越的电气性能。     

基于人工表面等离激元的宽带漏波天线

为了解决漏波天线带宽有限和整体尺寸较大的问题,文章提出了一种新型宽带漏波天线.该天线由人工表面等离激元传输线和非对称圆形贴片组成,其工作频段为7～15 GHz(相对带宽为72.73％),能够从后向至前向连续波束扫描,波束扫描角度为69°,同时具有稳定的高辐射增益.该天线的最大仿真增益达到13.1 dBi,测试增益波动仅...     

宽频带宽角域扫描的圆极化相控线阵设计

针对传统相控阵工作频带窄、圆极化波束扫描角度小的问题,设计了一款宽波束天线单元以及1×6相控线阵。采用叠层贴片技术展宽天线的阻抗带宽,设计新型的三维地结构拓展天线的波束宽度,利用介质匹配层技术改善天线在低仰角区域的阻抗匹配,并通过双点馈电实现圆极化辐射。仿真与实测结果表明,天线单元的3 dB波束宽度在4.3~5.6 GHz的频带内均大于115°。天线阵列在4.5~5.3 GHz的频带内,主波束的最大扫描范围为-57°~58.5°,其3 dB波束覆盖范围达到185°,在主波束的扫描范围内轴比小于6 dB,具有良好的宽频带宽角域的圆极化扫描特性,在卫星通信、移动基站等领域有广阔的应用前景。     

一种新型频率固定相控波束扫描的微带漏波天线

提出了一种崭新的带移相器双端口馈电微带漏波天线。通过控制微带漏波天线末端馈电端口移相器 ,其输入电流激励相位发生变化 ,成功地实现了工作频率固定下的微带漏波天线主波束扫描。当工作频率为 7GHz时 ,微带漏波天线主波束扫描范围可以达到约 2 1°。     

基于Minkowski分形CRLH结构的微带漏波天线

将Minkowski分形理论应用于文献中提出的复合左右手传输线结构,使其带宽从2.78～3.30 GHz展宽到2.02～4.53 GHz.对新结构色散特性进行分析,给出色散曲线,确认其为平衡结构,并在此基础上设计了一款微带漏波天线.由于复合左右手单元结构具有左手和右手特性,漏波天线可以分别实现后向辐射和前向辐射,在平衡状态下,消除了平衡点附近的阻带效应,平衡点处的群速不为0,有行波传播,天线可产生横向辐射.仿真和测试结果表明,该文所设计的漏波天线工作频段为2.35～3.20 GHz,相对带宽为30.6％,且能实现从后向到前向连续辐射,克服了传统漏波天线后向辐射角和前向辐射角不连续的缺点.     

基于方向图可重构天线的新型宽角度扫描相控阵

提出了一种基于方向图可重构天线单元的新型相控阵,并分别研究了其均匀、非均匀相控阵的扫描特性。通过重构天线单元的工作状态和各单元的激励,其均匀阵可以获得低副瓣电平等较好的辐射性能,其非均匀阵的主波束扫描范围达到±80°,在扫描平面内3dB 主波束覆盖可达176°,且栅瓣电平很低。研究表明了重构天线在相控阵天线研究中 的广阔应用前景。     

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.