【作者】 王平；

【导师】 文光俊；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2013， 博士

【摘要】 天线作为无线通信系统中不可缺少的关键部分，它的性能对整个系统的工作能力起着决定性的作用。同样地，实现电磁信号发射和接收的端射天线或阵列的性能决定了反辐射导弹捕获、跟踪目标，并定向攻击辐射源目标的战场效能。随着现代反辐射导弹技术的发展和飞跃，对天线的技术要求也提出了更高的指标，如高增益、宽的3dB束宽、低的旁瓣电平、极宽频率带宽、小的尺寸、简单的安装结构，等等。另一方面，在设计反辐射导弹表面的端射天线时，还受到金属表面、介质天线罩的影响，也给天线设计带来了极大的困难。然而，采用传统的天线设计技术来应对这些要求和困难是极具挑战性的。为突破相关技术难题，需结合电磁研究领域其它分支学科，继续深入开发端射天线的若干关键技术。本论文在国家重点实验室基金项目“端射共形测向天线阵研究”的资助下，以传统Vivaldi天线和经典对数周期天线阵为研究基础，探索和发展小型化超宽带端射天线的结构和机制，研究和解决适合弹载的超宽带端射天线的理论、设计、测试等关键技术。主要研究工作如下：1.提出一款高增益的平衡Vivaldi天线：针对传统平衡Vivaldi天线在高频范围内(>11GHz)端射方向的增益值急剧下降，主波束严重偏离端射方向等技术问题，采用延长介质基板前端的方法，形成一个三角形介质棱镜，使主波束方向更接近端射方向。然后，沿着每块金属贴片的外边缘切除一个三角形金属片，并在其外边缘加载开口槽线，进一步增加天线辐射方向图的前后比，提高天线的端射性能。最后，研究了高增益天线放置于金属表面时天线辐射场的变化规律。2.首次分析了金属圆柱体表面的端射天线辐射特征：以平衡Vivaldi天线作为测向天线单元，通过分析金属圆柱体表面的水平极化天线辐射场，掌握水平极化天线辐射场的变化规律。3.提出一款垂直极化的小尺寸、超宽带单极Vivaldi天线结构：根据传统共平面Vivaldi天线设计原理，设计单极Vivaldi天线结构，然后选择指数曲线外边缘结构，以及在天线末端集成一个100欧姆的电阻，增加更低的谐振频率，扩展了带宽。在此基础上，运用参数分析，掌握天线参数变化对天线辐射场的影响机制，获得最佳的天线尺寸。4.研究介质天线罩对端射天线辐射场的影响机制：目前所出版的论文和书籍都集中研究天线放置于天线罩内部区域时的工作性能，而天线分布在天线罩外部区域的研究则很少报道。因此，有必要深入研究介质天线罩对天线辐射场的影响机制。文中先给出TE波和TM波入射到介质层表面时所发生的一些物理效应，推导出功率传输系数的表达式，并运用图形直观地表示介质层对不同极化电磁波的影响规律。结合理论分析，解释介质天线罩对水平极化和垂直极化天线的不同工作机制，总结出介质天线罩对不同极化天线辐射场的影响规律。最后，运用参数分析，研究介质天线罩的参数变化对垂直极化天线辐射场的影响机制。5.提出单极对数周期天线阵辐射方向图的稳定性条件，并设计了一款应用在金属圆柱体表面的单极对数周期天线阵：基于经典对数周期天线阵的设计和工作原理，分析和研究单极对数周期天线阵的稳定性辐射条件。结合相关理论分析，设计一款运用在金属圆柱体表面的宽频带单极对数周期天线阵，该结构具有工程实用性。更多还原

【Abstract】 Antenna is an indispensable key part of wireless communication systems, itsperformance plays a decisive role in whole systems. Similarly, the endfire antennaelement or array on the surface of missile, which is responsible for sending andaccepting the electromagnetic signals, determines the battlefield performance when theanti-radiation missile acquires and tracks the target, and launch directional attack on theradiating source. With the rapid development of modern anti-radiation missile, thetechnological requirement of antenna is becoming higher and higher. For example, theantenna is expected to work at high gain, wide3dB beamwidth, low sidelobe level, verywide bandwidth, small size, simple install configuration, and so on. Meanwhile, theantenna also suffers from the effects of metal surface and dielectric antenna radome,which further increase the design difficulty. If we use conventional antenna-designtechnique to design an antenna which meets the engineering requirements andovercomes the difficulty, it is a very highly challenging. Thus, it is necessary to researchon the key technique of endfire antenna, and break through the technical difficulty byusing other correlative electromagnetic subject. Under the support of the State KeyLaboratory Foundation (Research of Endfire Conformal Direction-Finding AntennaArray), this dissertation, based on original Vivaldi antenna and log-periodic antennaarray, explores or develops compact ultra-wideband endfire antenna structure andworking mechanism, and researches and resolves the key techniques of ultra-widebandendfire antenna which is suitable for the surface of missile, such as, theory, design,measurement, and so on. The main research workings are as follow:1. A wideband high gain balanced Vivaldi antenna is proposed: because originalbalanced Vivaldi antenna has very low gain value in endfire direction when it isworking in high frequency ranges (>11GHz), and the main beam direction of that willdeviate from endfire direction largely, this chapter adopts a novel technique ofelongating of the supporting substrate of an original balanced antipodal Vivaldi antennabeyond its aperture, and shaping of triangular configuration, which lead to the mainbeam direction close to the endfire direction. And then, the antenna will be modified byonly cutting triangular patch along the terminal of two dual exponential curves, andloading three I-shaped notched slots on the edge of every copper layer, which further enhances the front-end ratio of radiation field. Finally, the chapter also analyzes theeffect of metallic surface on the radiation field when the proposed antenna is placednear a metallic surface.2. The section first analyzes the radiation characteristic of endfire antenna placedon surface of metal cylinder: the chapter uses the balanced Vivaldi antenna as theelement of direction-finding antenna array, and analyzes the radiation field of thehorizontally polarizated antenna placed on metal surface, aiming to find the variation ofthe radiation pattern.3. A compact ultra-wideband monopole antenna with vertically polarizedcharacteristic is proposed: Firstly, by using designed theory of conventional uniplanarVivaldi antenna, a monopole configuration is proposed, then selecting anexponent–shaped exterior edge configuration and integrating with a resistance of100in the end of the proposed antenna, which lead to further add resonant frequencybandwidth. On this basis, a parametric study is presented for knowing the variation ofthe radiation pattern, aiming to obtain optimal dimension.4. Effect of dielectric antenna radome on radiation pattern of the endfire antennamounted on a large conducting cylinder is presented: There are few literatures whichdiscuss the effect of antenna radome when the proposed endfire antenna is placed on theexterior of dielectric antenna radome, so the chapter firstly presents some physicsperformance and deduces the expression of power transmission coefficient when amodel simulating slanting the incidence of the TE waves or TM waves into thedielectric slab is adopted, and uses the graph curve attribute to show the effect ofdielectric board on the radiation field. Subsequently, by using theoretical analysis thesection shows the comparison between effects of dielectric antenna radome onhorizontally polarizated antenna and vertically polarizated antenna, and summarizes theeffect of dielectric antenna radome on radiation field of different polarization antenna.Finally, a parametric study showing the impact of the various parameters of dielectricantenna radome on the vertical-polarization antenna performance is presented.5. It puts forward the constant radiation condition of monopole log-periodicantenna, and designs a monopole log-periodic antenna array which is suitable forplacing on the surface of missile. The section, based on the design theory of classicallog-periodic antenna array, analyzes and studies the constant radiation condition ofmonopole log-periodic antenna array, then designs a wideband monopole log-periodic antenna array placed on the surface of missile, which possess practical engineeringapplication.更多还原