电磁带隙的超宽带阻带天线设计

设计了一种电磁带隙(EBG)结构.根据实际应用要求,在一种超宽带微带天线上加载电磁带隙单元,设计出一种阻带天线.对天线的多个参数进行讨论并优化设计,根据仿真实验制作出天线实物.实验结果说明:天线在3.11～5.97 GHz的频带范围内,电压驻波比(VSWR)值大于2;在5.46 GHz处达到了9.23的峰值,阻带范围覆盖WiMAX (3.4～3.7 GHz),C-band (3.7～4.2 GHz),WLAN(5.15 ～5.35 GHz/5.725～5.825 GHz)这三个频段,且天线增益在阻带内明显降低.     

一种Peano结构的圆极化微带天线设计

在天线结构优化设计中,为了改善电磁带隙结构下阵元间距过大造成天线阵极化特性和增益性能下降的问题,提出设计了一种Peano结构下的圆极化微带天线.使用直接传输方法分析有限周期的一阶Peano结构的表面波带隙,将电磁带隙结构放在微带天线周围,通过减小电磁带隙结构和天线的间距,优化天线结构和天线的参数,缩小阵元之间的间距.仿真结果表明,与传统的电磁带隙结构微带天线相比,改进设计能有效减小圆极化天线阵中阵元间距,抑制阵元之间的互耦,提高阵元的方向性和天线阵性能.     

对相移同轴电缆Bragg电栅特性的研究

对同轴电缆进行周期性钻孔形成同轴电缆布拉格电栅（ CCBEG）,通过三维电磁仿真软件Ansoft HFSS（高频结构仿真器）对CCBEG进行了建模和仿真,仿真结果和实验结果进行对比,频率特性基本一致,仿真结果可以作为电栅特性研究的依据。对于传感应用,提出了相移CCBEG并对周期长度、钻孔尺寸等参数进行了优化,减小了线宽,提高了传感精度。研究为进一步实现基于CCBEG的传感器研究和参数优化提供了理论指导和实验基础。     

电磁共振式无线电能传输结构分析

本论文讨论和比较了四种实现无线电能传输的方法,电磁感应式、电磁共振式及射频传输。综合考虑了传输距离、传输功率及效率等因素,并最终选用电磁共振式传输作为本论文的研究对象。电磁共振式无线电能传输的原理是电能可以在两个有着相同共振频率的LC谐振器之间传输。谐振器由一个具有大电感的线圈再串联或并联一个小电容组成。电能传输的必要条件是两个LC谐振电路有相同的共振频率。本论文在基于一定理论分析后,作者制作了一个发送器和一个接收器。其电路原型是一个12匝,半径为9cm的线圈,连接一个1nF的电容构成。一个信号发生器作为初始的能量源。在高频共振条件下,这个无线电能传输系统成功在一定距离下点亮两盏LED灯。基于以上成果,本文还对传输电路的构成方式从负载电压、传输距离两方面进行了比较,并得出结论。     

螺旋滤波器的设计方法分析

介绍一种设计螺旋滤波器的方法,并给出一个滤波器的设计实例和仿真结果。设计时先用微波网络分析和滤波器设计理论计算出腔间耦合系教和外界Q值的理论值。在用高频结构仿真软件（HFSS）进行仿真时,采用了一种准螺旋结构得出实际的谐振腔的耦合结构,然后进行整体仿真优化,完成整个设计。应用这种方法可以简化螺旋滤波器仿真并大大减少有限元网格的划分时间,提高仿真效率,设计准确。     

微型ICP激发源微电路组件的参数设计

本文简要介绍了一种采用微结构平面螺旋线圈的新的ICP(电感耦合等离子体)光谱激发源.作者设计加工出的基于PCB(印刷电路板)镀金工艺的微型ICP激发源在13.56MHz下成功启燃,并给出了ICP火炬照片.详细介绍了作者研制的微型ICP激发源的平面螺旋电感和交指电容的参数设计方法,给出了设计版图和实物照片,微结构线条宽度和间隙在数百微米量级.展望了平面螺旋电感和交指电容在微型ICP激发源的中的应用前景.     

带曲率补偿的带隙基准电流源的设计

简单介绍了带隙基准源的基本原理,给出了一款基于Widlar结构的带曲率补偿的带隙基准电压电流源的设计方法,通过采用TSMC₀.5μm工艺库对电路进行仿真,在-40～150℃的温度范围内,其带隙基准的输出具有12ppm/℃的温度系数,电流基准的输出具有42ppm/℃。此外,文中还对曲率补偿电路的工作原理进行了分析,并且通过仿真波形对曲率补偿的工作机制进行了讨论。     

一种结构简单的CMOS带隙基准电压源设计

本文提出了一种结构简单高电源抑制比的CMOS带隙基准电压源,供电电源3.3V.采用CSMC 0.5um CMOS工艺.Spectre仿真结果表明,基准输出电压在温度为-40～+80℃时,温度系数为45.53×10-6/℃,输出电压在电源电压为2～5V范围内变化小.电源抑制比达到-73.3dB.     

电推卫星方圆过渡结构轻量化设计

讨论在考虑强度约束和动力学约束的情况下,全电推进卫星的方圆主承力过渡结构的轻量化设计.利用三维拓扑优化技术对方圆过渡结构进行优化设计,确定方圆过渡结构的传力路径,并据此进行创新构型设计.对创新构型进行强度及动力学分析,验证其在强度性能、动力学性能上的优越性.     

新型一维微带开口环PBG结构的研究与设计

本文在对一维光子带隙PBG(Photonic Bandgap)结构进行设计时,提出一种新型的开口环PBG结构。该结构在接地板上刻蚀周期性的开口环,可分为圆形双开口环和方形双开口环两种结构。结果表明:圆形双开口环PBG结构简单易于实现,并且可以获得较宽的通带及较小的通带波纹。在圆型双开口环的基础上改进即得到方形双开口环PBG结构,结果显示出该方形结构具有良好的通带特性,并且可以有效地改善通带的平坦度,减小插损,适用于微波及毫米波集成电路。     

Isolation enhancement between tightly spaced compact unidirectional patch‐antennas on multilayer EBG surfaces

In this article, ultracompact unidirectional patch antennas are used in different two‐antenna systems for biomedical applications at 5.2 GHz. Multilayer mushroom type electromagnetic bandgap (EBG) structures are designed as slow‐wave medium to reduce the size of the individual patch antennas to 0.1λ₀ by 0.18λ₀. Various techniques are investigated herein to improve antenna isolation for an enhanced Multiple‐Input Multiple‐Output (MIMO) performance. First, the coupling between 0.3λ₀‐spaced antennas is verified to occur dominantly through radiation and near‐field coupling between the patches rather than through substrate‐bound modes. Second, various configurations are proposed to suppress antenna coupling. These approaches include reorientation of the antennas and employment of parasitic radiators between the patches. A novel design is presented in which a unidirectional parasitic slot radiator on an EBG reflector is inserted between the antennas to decouple them. Measurement results confirm efficacy of these approaches in mitigating antenna coupling by more than 11 dB in the operating bandwidth of the antennas. The compact patch antennas maintain efficiency values of higher than 70%. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:30–38, 2015.     

Design of band-gap grid structures

This paper discusses issues related to designing band-gaps in periodic plane grid structures. Finite element analysis is used to solve the dynamic behavior of a representative unit cell and Bloch–Floquet theory is used to extend the results to the infinite structure. Particular attention is given to the addition of non-structural masses that are introduced as design variables. These are used to create desirable features in the dispersion diagram. Physical insight is presented into the optimal choice of locations where masses should be added and the results of several numerical examples are provided to highlight this and other features of how band-gaps can be created and located at desired frequency ranges. The effect of the skew angle of the underlying grid structure is also explored, as are mathematical refinements of the modelling of the beam elements and the rotational inertia of the added masses. A scaling feature between the size of the reducible and the irreducible reference cell is exploited and the manner in which this can simplify optimization approaches is discussed.     

一种易调谐的小型GPS微带天线设计

提出了一款新颖的易调谐小型GPS微带天线结构。采用正方形贴片作为辐射单元,通过切角微扰实现右旋圆极化辐射;在贴片中心开槽和四周开缝,利用贴片曲流技术减小天线的尺寸;使用同轴中心馈电加载微带匹配段,实现阻抗的匹配。文章给出了天线的设计思路,并进行了大量的电磁仿真优化,最终对天线进行了加工实验。实验结果表明,在设计的频带内,天线具有较好的阻抗匹配和圆极化辐射特性。该天线具有结构紧凑、易于调谐的特点,具有良好的应用前景。     

基于光纤光栅应变传感器的监测系统设计

通过在桥梁、建筑等重大工程结构的具体实施应用中，对光纤光栅工程结构应变长期监测系统的设计方法、基本构成、传感网络的优化、系统的温度补偿、现场传感器的布设、保护工艺等诸多重要问题进行了分析和研究，并加以解决。应用此系统对大型重量级工作制钢吊车梁的加固进行了监测，通过与理论的对比表明采用光纤光栅应变传感网络对大型构件实现应变检测是可行的。     

Application of a fourth-order compact ADI method to solve a two-dimensional linear hyperbolic equation

In this paper, a compact alternating direction implicit method is developed for solving a linear hyperbolic equation with constant coefficients. Its stability criterion is determined by using von Neumann method. It is shown through a discrete energy method that this method can attain fourth-order accuracy in both time and space with respect to H ¹- and L ²-norms provided the stability condition is fulfilled. Its solvability is also analysed in detail. Numerical results confirm the convergence orders and efficiency of our algorithm.     

TLM modeling of a probe‐coupled cylindrical cavity based on compact wire model in the cylindrical mesh

This article describes an implementation of a compact wire model into the three‐dimensional transmission‐line matrix (TLM) cylindrical mesh for the purpose of an efficient analysis of probe‐coupled cylindrical microwave cavity devices. Because of a cylindrical grid structure and empirical nature of the compact model, this implementation has to take into account a change of wire model parameters with a variable cross section of the TLM nodes through which a wire conductor passes. The model accuracy has been experimentally verified and compared with the corresponding results reached by the TLM method based on a rectangular grid in order to consider its advantages. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

层次化区域匹配指导的视频颜色迁移

提出了一种基于层次化结构的视频颜色迁移方法。利用层次化分割技术对视频帧进行区域分割并将分割区域之间的组织关系用树的形式来描述,形成表示图像组成区域的具有层次化特征的树状结构。通过定义表示图像的树之间的层次化结构的相似性比较方法,对迁移图像之间的局部区域特征进行相似性比较,以寻找目标图像与参考图像局部迁移的最佳区域。在此基础上,利用颜色概率分布迁移的方法在图像的不同区域上进行局部颜色迁移以实现保持目标图像视觉特征的目的。     

Design of a compact size tag antenna based on split ring resonator for UHF RFID application

In this article, a new design of miniaturized split‐ring resonator antenna using a meander line technique with a simple impedance matching method applicable to UHF‐RFID tags is presented. The new approach is based on the integration of a meander line into the radiating element of SRR to reduce the electrical tag size and a theoretical demonstration to calculate the conjugate impedance matching and directly attach the antenna with the chip. The new SRR antenna, which is printed on the flexible substrate Arlon CuClad 250LX, is designed using Alien Higgs 3 RFID ASIC whose input impedance is 25‐j190. The prototype antenna has a low‐cost compact size (18.28 mm × 18.28 mm) with a read range higher than 4 m within the RFID UHF band and with a roughly 4.2‐m peak range at 915 MHz. As a proof of behavior, a tag prototype is fabricated and measured to operate at a UHF RFID band. Based on some works' results, an optimized design is obtained with a 48% size reduction compared with the classic split ring resonator antenna and with a good impedance matching the antenna with RFID ASIC without the need for any external matching network.     

雷达目标特性测试的控制采集模块设计

介绍了雷达目标散射特性测试系统控制采集模块的组成、工作原理、软件和硬件设计，其中重点介绍了使用Windriver软件设计ISA接口卡的Windows驱动程序的方法。该模块通用性好、自动化程度高、操作简便，达到了雷达目标散射特性测试的要求。