Ku频段宽带相控阵天线技术研究

阵列天线易于实现高增益、波束扫描及波束赋形等功能,成为现代无线通信、导航、雷达等信息系统收发信号的主要手段。为满足高速率、广覆盖、多功能等发展需求,现代无线信息系统要求阵列天线具有宽工作带宽、宽角波束扫描能力及平面化、低剖面等特性。为此,文中以Ku频段、低剖面、宽频带相控阵天线为研究方向,基于微带天线宽带化技术、L型探针耦合馈电技术及加载等效腔体结构,开展微带天线的宽带化和相控阵天线的宽角扫描技术研究。文中提出了一种基于L型探针耦合馈电结构的具有宽带、宽角扫描能力的8×8阵列天线。实测结果表明,在VSWR<3时,在13.0～18.0 GHz阻抗带宽内(相对带宽为32.3%),该阵列天线在E面和H面均可实现±60°的扫描覆盖范围。实测结果和仿真结果具有较好的一致性。     

低剖面渐变槽线天线单元设计

基于有限元仿真软件通过设置周期性边界条件的方法,分析了影响渐变开槽天线单元宽带宽角扫描性能的关键因素。通过在安装天线阵列的反射面上铺覆新型阻抗匹配材料,克服了天线高度对驻波带宽的限制,实现了天线的小型化设计。加工制作了一个20×16天线单元的实验小型面阵,并对其有源扫描驻波进行了测试。实测结果与仿真结果吻合,表明该天线在8GHz～12GHz带宽内±45°扫描范围内性能优异,可广泛应用于宽带宽角扫描相控阵天线系统。     

一种机载超宽带相控阵雷达T/R组件设计

为满足多功能电子系统对天线带宽、天线剖面和波束覆盖范围的需求,提出了一种工作在6~18 GHz的平面双极化低剖面宽角扫描相控阵天线. 首先,为了抑制由非平衡短路式巴伦引入的天线带内寄生谐振模式从而拓展天线带宽,在天线阵列中加入了由短路金属柱和印制金属盘构成的脊型结构;然后,设计了基于超表面的宽角扫描阻抗匹配层,以降低波束扫描时的反射损耗;此外,在该天线的介质层中设计了周期性分布的空气孔,以降低天线辐射体周围的有效介电常数,进而消除波束扫描时的表面波激励. 基于上述方法,利用多层印制电路板工艺,在保持天线低剖面特性的同时实现了超宽带宽角扫描性能. 仿真结果表明,该阵列在典型方位角φ=90°和φ=0°分别具备±75°和±60°的波束扫描能力,且阵列剖面高度小于3.52 mm. 为了验证该设计的正确性,制作了一个阵列规模为8×8的双极化天线样机并对其进行实验,实验结果与仿真结果吻合较好. 该天线具有超宽带、低剖面、宽角扫描特点,为多功能电子系统提供了一种新颖的天线阵结构.     

一种电磁耦合馈电宽带宽角扫描微带天线阵列

文中提出一种可实现宽频带大角度波束扫描的低剖面相控阵微带贴片天线。为实现宽带特性,该 阵列天线采用了缝隙电磁耦合馈电和双层贴片的设计。由于介质基板的堆叠,微带贴片阵列在高频大角度扫描 时往往会受到表面波的影响,从而引发高次模谐振并带来扫描盲区。针对这一现象,通过对堆叠的介质基板开槽 抑制表面波传播,从而改善高频的阻抗匹配特性。此外,还在贴片两侧加载寄生条带以优化低频阻抗匹配,拓展 带宽并保持低剖面外形。该天线剖面高度仅4. 6 mm,约为高频波长的0. 19 倍,可满足许多低剖面载体平台的应 用需求。仿真结果显示,该天线在±45°扫描和±60°扫描时可分别实现57. 9%(有源驻波比≤2. 25)和44. 4%(有 源驻波比≤2. 75)的相对带宽。基于该设计加工了一款8×8 阵列样机。阵列样机的驻波及方向图测试结果与8× 8 阵列的全波仿真结果吻合良好,有效验证了该微带贴片天线阵列的宽带和宽角扫描特性。     

一种低剖面阵列天线散射特性研究

宽频带宽角域隐身是下一代隐身飞行器平台的关键特征之一,发展超宽带低剖面高隐身传感器已成为下一代隐身飞行器平台的必然趋势。文章瞄准天线阵列超宽带、轻薄化、高隐身的需求特点,设计了一款低剖面的宽带宽角相控阵隐身阵列天线。采用强互耦超宽带相控阵列技术,使阵列天线具备超宽带轻薄化低剖面特征,并通过宽带宽角阻抗匹配、阵列误差控制等手段缩减阵列天线雷达散射截面。仿真及测试结果表明,该低剖面天线阵列具有优良的宽带宽角辐射特性和低散射特性,基本满足下一代隐身飞行器平台对轻薄化低RCS阵列天线的需求,具有一定的工程应用价值。     

无人机载Ku波段有源相控阵天线

设计了一种无人机载雷达的Ku波段有源相控阵天线,分析了有源相控阵天线的系统组成、模块布局和设计思路,实现了高集成、低剖面的有源相控阵天线设计,并可同时实现SAR和GMTI功能。设计了32行线源的宽边纵缝驻波阵形式的波导裂缝阵列天线,通过加脊和分区馈电法扩展了天线的工作带宽。采用FFT反演算法在微波近场暗室中对有源相控阵天线进行了校正补偿。实测结果表明该有源天线可以实现两维-20dB的低副瓣电平,并可在俯仰向实现±60°的相控阵扫描,实测方向图与仿真结果相吻合。本天线具有宽带宽角扫描、低副瓣、低剖面、结构紧凑等优点。     

一种新型宽带宽波束圆极化微带天线的设计

设计了一种新型的用于卫星通信的三馈宽带圆极化微带天线。天线在1500~1900 MHz频带内实现圆极化辐射。馈电网络采用三功分馈电,增加了轴比带宽和宽角轴比带宽;网络和附加的寄生贴片展宽了阻抗带宽;延伸天线介质衬底增大了波束宽度。实测结果表明:天线电压驻波比(VSWR)小于2的带宽达到62.5%,轴比(AR)小于3 dB 的带宽达到33%,实现了天线宽带宽波束性能。     

基于双F型馈电探针的宽带圆极化微带天线设计

分析和设计了一种采用双F型馈电探针结构的宽带圆极化微带天线。天线采用Wilkinson功分移相器形成两路幅度相等、相位差90°的信号,通过两根F型馈电探针对空气介质层上方的方形贴片进行正交耦合馈电来实现圆极化。仿真结果表明:该天线能够实现67.2%的阻抗带宽(VSWR<2)以及29.3%的3 dB轴比带宽,具备良好的宽带圆极化和宽角扫描特性,并且,天线的剖面高度仅为0.09λ0(λ0为中心频率对应波长),具有广阔的应用前景。     

一种低剖面宽带宽角扫描阵列天线的设计

基于超材料技术理念,在考虑阵元间互耦效应下,优化设计了一种低剖面宽带宽角扫描阵列天线,使该阵列剖面为最低工作频率的四分之一波长,相对带宽达55%下,工作频段内中心阵元的平均工作效率高达87%以上,30o扫描角范围内的平均有源驻波系数小于2.0,其阵元方向图E面、H面的半功率波瓣宽度大于60o。研制的6伊8阵列样机测试结果说明了阵列天线具有良好的宽带宽角扫描特性,同时该天线具有结构紧凑、重量轻和易于实现的特点,在相控阵雷达天线中有很大的应用价值。     

一种高增益宽带窄边频率扫描天线设计

通过引入复合左右手结构,设计实现了一种高增益宽带窄边频率扫描天线。通过引入宽带Vivaldi天线作为天线阵元,实现了天线的宽带化,并使用复合左右手结构传输线对单元进行馈电,提高了扫描范围。分析了不同单元数量对天线扫描性能的影响,并对天线在不同单元数量下的电场分布进行了分析,确定了合理的单元数量。该天线阻抗匹配带宽为12～17.53 GHz,波束扫描角度为42°,最高增益为16.54 dBi。对天线实物进行了制作,在微波暗室中进行了测试,实测结果与仿真结果吻合度较好。由于该天线具有低剖面、高增益、带宽宽、结构简单等特点,在舰载和机载设备中有一定应用前景。     

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.     

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.     

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.     

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     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first