改进型超宽带Vivaldi天线设计与仿真

在传统Vivaldi天线结构的基础上,设计了两种适用于宽带信号收发系统的改进型渐变槽Vivaldi天线以及同轴馈电型对踵Vivaldi天线,并利用电磁仿真软件HFSS对这两种Vivaldi天线的性能进行优化分析.通过对不同结构Vivaldi天线的对比分析结果可以看出改进型渐变槽Vivaldi天线和同轴馈电型对踵Vivaldi天线在频段、带宽、驻波比等方面均达到宽带传输系统的设计要求.     

用于超宽带介电常数测量的Vivaldi天线设计与仿真

在传统Vivaldi天线结构的基础上,设计了两种适用于混合材料介电常数测量的改进型渐变槽Vivaldi天线以及同轴馈电型对踵Vivaldi天线,并利用三维电磁仿真软件HFSS对这几种Vivaldi天线的性能进行优化分析。通过对不同结构Vivaldi天线的对比,分析结果可以看出这两种改进型渐变槽Vivaldi天线和同轴馈电型对踵Vivaldi天线在频段、带宽、驻波比等方面均达到超宽带介电常数测量系统的设计要求,可应用于测量混合材料的介电常数。     

关于Vivaldi超宽带天线设计方案的研究

文章对微带线馈电结构的Vivaldi超宽带天线进行了设计,并对设计的Vivaldi天线进行了计算辅助优化设计,同时制作了试验样机。仿真测试结果表明,该天线在规定的3.1GHz～10.6GHz频段内可以得到良好的传输性能和辐射性能,与理论设计吻合,达到宽频带特性的设计要求,为Vivaldi超宽带天线的设计提供了新的思路。     

关于Vivaldi超宽天线设计方案的研究

文章对微带线馈电结构的Vivaldi超宽带天线进行了设计,并对设计的Vivaldi天线进行了计算辅助优化设计,同时制作了试验样机.仿真测试结果表明,该天线在规定的3.1GHz-10.6GHz频段内可以得到良好的传输性能和辐射性能,与理论设计吻合,达到宽频带特性的设计要求,为Vivaldi宽带天线的设计提供了新的思路.     

频率步进探地雷达及其在地雷探测中的应用

频率步进方法是探地雷达技术的工作体制之一,与时域无载频脉冲体制的探地雷达技术相比,在探测性能上具有较多的优越性.本文在简述其工作原理的基础上,介绍了作者研制的一种频率步进探地雷达系统,该系统主要用于对地雷目标进行三维成像探测.在研制该雷达系统过程中,对已有的反对称Vivaldi天线提出了改进设计.实验测量结果表明,本文研制的反对称Vivaldi天线与传统的同类天线相比,性能更加优越.同时,为了得到更加清晰的地雷图像,本文还分别引入了f-k偏移成像方法和合成孔经雷达(SAR)处理技术对雷达探测信号进行处理,得到了满意的结果.探测实例表明,频率步进探地雷达系统能够实现对浅层地下地雷目标的高分辨率三维成像探测.     

平衡对拓Vivaldi天线的改进设计

针对平衡对拓Vivaldi天线存在方向图不对称及增益低的缺点,在分析和设计常规平衡对拓Vivaldi天线的基础上,通过加载半椭圆介质板和开不对称半椭圆槽,设计了一副工作在10~20 GHz的天线并进行了仿真分析。结果表明,该天线方向图保持良好对称,方向图E面峰值偏移现象得到显著抑制,改进后的天线具有较高的增益和较强的方向性。     

超宽带全金属Vivaldi 天线的设计

设计了一种全金属的Vivaldi 天线,当频率为3 ~17 GHz 时,其VSWR<2,在宽边扫描情况下,VSWR 小于2. 0 的带宽能达到11 GHz。它不仅具有频带宽、方向性好等特点;同时,它还能解决传统Vivaldi 天线制作工艺复杂、制作成本高、物理强度低等问题,能更好地应用于高功率雷达等领域。文中利用高频结构仿真软件HFSS 对设计天线的几何尺寸进行了优化,并进行了仿真与分析,通过计算天线的驻波比、方向图、增益等性能验证了天线的超宽带、宽边扫描的特性。     

一种毫米波宽角扫描Vivaldi 天线设计

设计了一种工作于毫米波段的金属Vivaldi 天线,天线宽带扫描性能优异。天线结构利用Vivaldi 作为辐射单元,将其集成到带状线耦合的馈电基板上,馈电网络与辐射天线结构相对独立,便于加工。通过仿真得到:在27. 2 GHz ~46. 0 GHz 范围内VSWR<2;在27. 5 GHz ~42. 2 GHz 频段内,天线驻波比在E 面和H 面45毅扫描范围内满足小于2 的匹配特性。文中利用设置周期性边界条件的方法优化天线尺寸并仿真分析天线参数对扫描带宽的影响。通过驻波比、交叉极化、天线增益的仿真分析天线性能。     

差分电路的二元子阵对称式Vivaldi天线阵列设计

<正>在传统Vivaldi天线的基础上,设计一种基于差分电路的二元子阵对称式新型天线。天线由两个对称的传统Vivaldi天线组成,但其相位设计上相差180°,使其辐射能同相叠加。该天线兼备超宽带与高增益,优化了传统Vivaldi天线在交叉极化上的性能,其对称结构也有助于降低天线的交叉极化。文献最后设计优化了一个1×12的宽带高增益线性阵列,在增益高达18.7d Bi的情况下,其带宽达31.6%,且方向图的交叉极化在-50d B以下。     

高增益印刷指数渐变天线研究与组阵设计

文章针对UHF频段设计指数渐变天线,以Vivaldi天线为原型,用加载矩形槽线的方法对Vivaldi天线进行优化设计。仿真和实测结果表明,天线在UHF波段具有驻波比低、频带宽的特性。最后采用线阵和并联馈电方式设计天线组阵,对水平组阵的增益仿真结果进行了分析。     

一种新型探地天线的优化设计

设计了一种新型超宽带平面天线.用FDTD研究了近地面天线的模拟计算问题,给出了天线的近场辐射性能.通过与平面蝶形偶极天线对比,结果表明该天线具有波形保真度好,对称的辐射方向图及后向辐射小等特点,进一步通过加载集中电阻优化设计,改善了天线的驻波特性.此天线不仅适用于探地雷达,还可以广泛地用于宽带通信和冲激雷达等系统.     

基于IRA天线的辐射波模拟器天线辐射性能研究

将通常用于超宽带领域的IRA天线应用到辐射波电磁脉冲模拟器中,提出一种基于反射器脉冲辐射天线的核电磁脉冲辐射波模拟器,分析其天线结构,给出四种馈臂形式,通过仿真比较了四种馈臂形式天线的辐射效率、远场和近场波形以及频率增益特性。结果表明:该天线的低频辐射效率有待进一步提高;具有锥形渐缩形式馈臂的天线能产生较好的远场和近场波形。IRA天线相较笼形天线具有体积小、方向性好等优点,如果能进一步提高其低频辐射性能,IRA天线将成为理想的辐射波模拟器天线。     

Improved feeding structures to enhance the performance of the reflector impulse radiating antenna (IRA)

This paper considers the improvement of the feeding structure of the reflector impulse radiating antenna (IRA). Full-wave analysis and measured results of the orthogonal cross-coplanar plate reflector IRA shows that the aperture fields are not uniform. The arm angle is varied as an optimization factor and it is shown that the arm angle of 70/spl deg/ has the maximum radiation efficiency. The termination load and the arm tapering effects are studied using simulation and measurement results. Furthermore, the effect of radius of circle of symmetry is studied and it is shown that a greater circle provides higher gain. A combination of transverse electromagnetic (TEM) horn antenna and the conical coplanar TEM transmission line is investigated to avoid tiny structure at the focal point and make the connection between the coaxial cable and the feeding arms more convenient. It is shown that a small triangle does not degrade the antenna performance but helps to excite the antenna by a coaxial cable. Finally a combination of the Vivaldi antenna and the coplanar transmission line is introduced to improve the antenna performance. The simulation results for the new antenna show that the antenna efficiency is improved to 45% at the frequency band between 2 GHz to 6 GHz in comparison to the 20.9% for the traditional design and 29.7% for the tapered design. The calculated far-field results of all these antennas are used to radiate a 0.5 ns impulse. The radiated impulse from the Vivaldi fed reflector IRA is 3.55, 2.41, and 2.12 dB higher than the same radiated impulses from the reflector IRA fed by a 45/spl deg/ traditional feeding arms, 70/spl deg/ traditional feeding arms, and 70/spl deg/ tapered feeding arms, respectively.     

Near- and Far-Field Characterization of Planar mm-Wave Antenna Arrays with Waveguide-to-Microstrip Transition

We present the design and characterization of planar mm-wave patch antenna arrays with waveguide-to-microstrip transition using both near- and far-field methods. The arrays were designed for metrological assessment of error sources in antenna measurement. One antenna was designed for the automotive radar frequency range at 77 GHz, while another was designed for the frequency of 94 GHz, which is used, e.g., for imaging radar applications. In addition to the antennas, a simple transition from rectangular waveguide WR-10 to planar microstrip line on Rogers 3003? substrate has been designed based on probe coupling. For determination of the far-field radiation pattern of the antennas, we compare results from two different measurement methods to simulations. Both a far-field antenna measurement system and a planar near-field scanner with near-to-far-field transformation were used to determine the antenna diagrams. The fabricated antennas achieve a good matching and a good agreement between measured and simulated antenna diagrams. The results also show that the far-field scanner achieves more accurate measurement results with regard to simulations than the near-field scanner. The far-field antenna scanning system is built for metrological assessment and antenna calibration. The antennas are the first which were designed to be tested with the measurement system.     

Spatial power combining for two-dimensional structures

The two-dimensional (2-D) hybrid dielectric slab-beam open and closed waveguide systems are suitable for the design of planar quasi-optical integrated circuits and devices. An open system consisting of an active E-plane amplifier array consisting of Vivaldi-type antennas with MESFET and monolithic microwave integrated circuit (MMIC) devices was investigated. The 4×1 MESFET amplifier array generated 11 and 4.5 dB of amplifier and system gain, respectively, at 7.12 GHz, and the cascade MMTC Vivaldi-type antenna produced 24 dB of amplifier gain at 8.4 GHz. Also, experiments on a new 2-D H-plane parallel-plate closed system with a stripline slot antenna is introduced, and the wavebeam-mode theory is presented. The new system minimizes scattering and isolation losses associated with open structures. The amplifier gain of the closed system based on slot antennas is compared to the open system based on Vivaldi antennas     

新型小尺寸带引向器波纹开眼对拓型Vivaldi天线

基于传统对拓型Vivaldi天线, 提出一种新型小尺寸对拓型Vivaldi天线.采用波纹、开眼和引向器等结构来展宽天线的工作带宽, 并分别对这三种结构对带宽的影响进行了分析.利用HFSS仿真优化得到的结构参数, 分别在两种介质材料上, 加工并测试了带引向器波纹开眼对拓型Vivaldi天线, 实测与仿真结果吻合.仿真与测试结果表明:两种介质上的天线工作频带均包含3~20 GHz, 尺寸仅为42.56 mm×40.16 mm×0.813 mm, 带内回波损耗S₁₁低于-10 dB, 带内增益均大于3 dBi, 最大增益达7.3 dBi, 交叉极化均小于-15 dB, 50%以上的频带交叉极化小于-20 dB, 最小可达-25 dB, 天线具有稳定的方向图, 良好的波形保真度, 是一种宽波束天线.     

Miniaturization of UWB Antennas and its Influence on Antenna-Transceiver Performance in Impulse-UWB Communication

In this paper, a co-design methodology and the effect of antenna miniaturization in an impulse UWB system/transceiver is presented. Modified small-size printed tapered monopole antennas (PTMA) are designed in different scaling sizes. In order to evaluate the performance and functionality of these antennas, the effect of each antenna is studied in a given impulse UWB system. The UWB system includes an impulse UWB transmitter and two kinds of UWB receivers are considered, one based on correlation detection and one on energy detection schemes. A tunable low-power Impulse UWB transmitter is designed and the benefit of co-designing it with the PTMA antenna is investigated for the 3.1–10.6 GHz band. A comparison is given between a 50 $\Omega $ design and a co-designed version. Our antenna/transceiver co-design methodology shows improvement in both transmitter efficiency and whole system performance. The simulation results show that the PTMA antenna and its miniaturized geometries are suitable for UWB applications.