一种新颖的双频微带天线设计

为了满足WLAN和Wi MAX双频无线通信,设计了一种结构简单的1/5双频微带贴片天线,该天线采用50Ω微带线馈电,集总端口激励方式。通过HFSS13.0仿真分析,天线可同时工作于Wi MAX(5.25 GHz)和WLAN(2.45 GHz)频段。仿真结果显示,优化后的天线在2.45 GHz和5.25 GHz频段的相对带宽分别为10%和22%,最大增益分别为2.33 d B和3.10 d B。带宽满足微带天线带宽的要求,且天线的辐射特性良好,结构简单,易于生产,有很大的应用前景。     

应用于WLAN的小型微带天线

为了满足手机无线局域网(WLAN)通信技术的要求,设计了一个三频段单极子贴片天线,通过2个L形支路产生双频辐射。并用软件对该天线进行仿真优化,实现了2.4 GHz、5.2 GHz和5.8 GHz三频段的同时工作,而且该天线结构简单,由L形贴片组合形成,体积小,所占面积为14.5 mm×16.5 mm。仿真结果表明,该天线的尺寸和性能可以在手机WLAN通信系统得到良好的应用     

应用于NB-IoT/WLAN/WiMAX的多频微带天线

针对物联网移动智能终端产品的要求,设计了一种可用于NB-IoT、WLAN和WiMAX的多频段微带天线。该天线采用矩形贴片天线结构,将馈电点放置在对角线附近位置,同时激发TM01和TM10模,并在贴片上开两个U型槽,实现在4个频段同时工作。利用电磁仿真软件ANSYS Electronics Desktop对天线进行仿真。结果显示,该天线在中心频点为1.89ＧＨｚ,2.43ＧＨｚ,3.52ＧＨｚ,5.25ＧＨｚ处的反射系数为-21.ｄＢ、-29.5 ｄＢ、-16ｄＢ、-19ｄＢ,实际加工制作天线并测试,实测结果与仿真结果比较吻合。天线贴片面积为22.1ｍｍ×18.4ｍｍ,尺寸较小,易于制造,可广泛应用于NB-IoT/WLAN/WiMAX通信频段。     

一种应用于WLAN/WiMAX的双频微带天线

提出了一种适用于WLAN/WiMAX的小型化双频微带天线。在矩形辐射贴片表面加载2/5形缝隙,改变矩形辐射贴片表面电流路径,使电流有效路径增加,实现天线的双频特性。通过电磁仿真软件HFSS 15.0对天线模型进行仿真分析。结果表明,天线可同时工作于WiMAX2.60 GHz和WLAN5.15 GHz频段,低频段和高频段的相对带宽分别为4%(2.53~2.64 GHz)和6%(5.14~5.48 GHz),最大增益分别为4.47 dB和1.35 dB,能够满足WLAN和Wi MAX的通信需求。天线整体辐射性能良好、结构简单、容易集成于前端电路。     

应用于WLAN/WiMAX的三频段微带贴片天线设计

设计了一种应用在无线局域网络(WLAN 2.4 GHz)和微波存取全球互通(WiMAX 3.5 GHz/1.8 GHz)无线通信领域中的小型化三频段微带贴片天线。结构设计主要通过在圆形贴片上开出一个近似T形槽的方式,该天线结构简单、尺寸小、加工方便、成本低且全向特性理想。为了便于数值分析和优化,在HFSS建立了该天线的电磁仿真模型。其研究表明,实测和仿真的结果吻合良好,该天线在其各频段内的回波损耗＜-10 dB,并具有良好的方向性和增益。在3个工作频带内电压驻波＜2,阻抗匹配特性良好,验证了该设计的合理性。     

WLAN小型双频微带天线的设计与分析

在分析传统缝隙微带天线的基础上,用传输线和空腔模型设计了一种可用于WiFi、WiMAX的WLAN微带天线。在贴片与接地板之间引入短路面使天线实现小型化,在贴片上开U型缝隙产生双频辐射,采用较低介电常数的介质基板和添加空气腔展宽了天线的带宽。仿真结果表明,当电压驻波比VSWR<2.0时,天线在2.45 GHz带宽为200 MHz(2.35～2.55 GHz),增益达到3.8 dB;在5.2 GHz带宽为1 050 MHz(5.0～6.05 GHz)增益达到8.8 dB。该天线覆盖了WLAN的所有频段,整体性能良好,增益较高,结构简单,易于实现,可以为实际无线通信系统的应用提供参考。     

基于复合辐射器的WLAN/WiMax多频CPW微带天线

提出了一种图形结构简单,可同时工作于WLAN和WiMax频段,且具有甚好的带宽性能的新型结构微带天线。该天线辐射器由三角形、矩形和圆形辐射单元组合而成,采用共面波导(CPW)进行馈电,并利用微扰量加载调谐天线的工作频率。由此设计制作的天线实测结果表明:在802.11b/g(2.4～2.4835GHz)频段,相对阻抗带宽为34%,回波损耗优于-10dB的频段覆盖为2.03～2.87GHz;在WiMax(3.4～3.7GHz)频段,相对阻抗带宽为37%,回波损耗优于-10dB的频段覆盖为3.17～4.37GHz;在802.11a(5.15～5.825GHz)频段回波损耗优于-10dB的频率范围覆盖为4.91～6.83GHz。该天线尺寸为65mm×50mm×2mm,可以集成应用于相关微波电路系统中。文中还给出了天线的设计尺寸,并对仿真和实测结果进行了对比与讨论。     

一种新型宽带双频段圆极化RFID读写天线

提出了一种新型宽带双频圆极化射频识别(RFID)读写天线,由上层的旋转对称折合振子和缝隙加载的方形贴片以及下层的紧凑型馈电网络构成。天线具有两个外部端口,分别激励低频0.9 GHz和高频2.45 GHz双频段的圆极化辐射。借助HFSS对天线进行了建模、仿真和优化,最后采用FR4板材制作天线实物并完成了试验测试。天线的外部尺寸为0.6λ0×0.6λ0×0.1λ0(λ0为0.9 GHz频点下的自由空间波长),测试结果表明,天线在低频段和高频段的-10 dB阻抗带宽和3dB轴比带宽分别为91.1%(4.9%)和87.8%(1.3%),频段内的峰值增益为5.48 dBic(3.63 dBic),最小轴比为1.1 dB(1.2 dB),在高低频段内,天线的辐射方向图对称稳定。该天线不仅能够满足全球通用型UHF频段(0.84~0.96 GHz)和ISM频段(2.4~2.5 GHz)RFID读写应用需求,而且具有低成本、易加工等优点,在物联网领域将具有很好的应用前景。     

低剖面可承载UHF/L双频共口径圆极化定向天线

为了满足毫米波高密度、宽角扫描共口径相控阵天线对高性能、紧凑型天线单元的需求,提出了一种宽带Ku/Ka共口径天线单元设计方案. Ku频段双极化天线采用“十”字形贴片作为辐射体,一对正交放置的缝隙用于激励两个正交工作模式. Ka频段天线为探针馈电的磁电偶极子天线,加载的4个小贴片起调节匹配和方向图的作用. 同时,Ka频段天线对Ku频段天线起寄生加载作用,在有效降低Ku频段天线谐振频率的同时扩展阻抗带宽. 仿真结果表明,Ku频段天线水平和垂直极化分别工作在14.4~17.6 GHz和14.4~17.4 GHz,−10 dB阻抗带宽分别为20% 和18.7%;Ka频段天线工作在30~40 GHz,−10 dB阻抗带宽大于28.5%,测试结果与仿真结果吻合良好. 所提出的共口径天线单元具有尺寸小、带宽宽的特点,其横向尺寸为8.5 mm×8.5 mm（0.45λ×0.45λ,λ为Ku频段中心频率16 GHz对应的波长）. 本文为高密度、宽角扫描共口径相控阵天线提供了新颖的天线单元设计方案.     

共面波导馈电的WLAN和WiMAX小型化三频段天线设计

本文给出了一款小型化多频段平面印刷单极子天线的设计和分析过程.该天线由一个矩形主辐射贴片和两个附属辐射枝节组成.主辐射贴片和两个附属枝节分别产生三个通带覆盖2.4/5.2/5.8GHz的WLAN工作频段和2.5/3.5/5.5GHz的WiMAX工作频段.天线的仿真结果表明,在WLAN频段以及WiMAX频段天线具有良好的阻抗带宽和辐射效率,天线的总尺寸为20mm×30mm×1.6 mm,结构紧凑,易于制作,适用于WLAN和WiMAX系统.     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks