【作者】 洪涛；

【导师】 龚书喜；

【作者基本信息】 西安电子科技大学 ， 电磁场与微波技术， 2011， 博士

【摘要】 隐身技术在现代电子战中占有重要的地位,由于隐身技术对作战平台战场生存能力的巨大影响,对于未来的高科技综合电子战而言隐身技术将得到大量的应用。天线是各种无线电子设备不可或缺的外部设备,只有天线正常工作才能保证电子设备整体正常工作,所以天线必须在复杂的战场环境中稳定有效的收发电磁波。天线这种工作特点使其成为战场上重要的目标,如何使己方电子设备天线正常工作的同时对敌方隐身成为隐身技术中亟待解决的问题之一。论文紧密结合“十一五”国防科技预研重点项目,着重围绕天线散射理论和天线雷达截面(Radar Cross Section, RCS)控制技术展开研究,针对目前军用雷达和通讯系统的隐身化需求,对超宽带天线、圆极化天线、单极子天线及圆极化阵列天线的RCS控制技术进行了研究。所取得的成果可以概括为:1、推导了天线辐射场的远场表达式,将其具体应用到了不同极化天线的分析中,推导了线极化天线和圆极化天线的辐射远场表达式。根据互易定理推导了接收天线的匹配接收幅度表达式,推导了线极化和圆极化接收天线的匹配接收幅度。推导了天线散射的基础理论公式以及线极化和圆极化被测天线的散射场表达式。这部分内容是后续章节对于线极化天线和圆极化天线分析的理论基础。2、根据天线设计和RCS控制的先后关系,提出了先根据辐射指标设计天线,再根据散射指标进行RCS减缩,最后根据实际情况对天线辐射性能进行补偿的天线RCS控制思路。根据以往的方法我们需要在天线设计之初就对天线的辐射性能留出一定的余量以弥补RCS减缩过程中对于辐射性能的损害,但是由于我们难以准确预估天线RCS减缩对于其辐射性能的影响,所以这一余量也是无法准确预知的。作者提出的新思路避免了由于余量过大而造成浪费和由于余量过小而造成重复工作。3、依据所提出的新思路,以超宽带平面单极子天线为参考,设计了一种具有低RCS特性的超宽带天线。对低RCS超宽带单极子天线的辐射和散射特性进行了研究,尤其针对天线上关键部位的尺寸对天线性能的影响进行了详细分析,通过与具有类似结构和性能的参考天线进行对比,研究了超宽带天线的散射机理。最后通过仿真和实验证明了设计天线的优异性能。4、根据对圆极化微带天线辐射和散射机理的研究,以矩形微带天线为参考,设计了一种可以在宽频带内保持低RCS的圆极化微带天线。对低RCS圆极化微带天线的辐射和散射特性进行了研究,分析了设计天线与一般天线在天线辐射性能的尺寸参数影响方面的异同,通过对比参考天线,分别从时域和频域的角度研究了天线的散射特性。最后通过仿真和实验证明该天线的优秀性能。5、根据来波频率与其工作频带的关系,天线散射可以划分为带内散射和带外散射;根据产生机理的不同,天线散射可以划分为天线模式项散射和结构模式项散射;作者综合以上两种划分标准,根据减缩频带和散射机制的不同将天线散射分成了相互关联的四部分:带内天线模式项,带内结构模式项,带外天线模式项和带外结构模式项。作者分析了各部分的特点,提出了天线带内结构模式项RCS控制的天线RCS控制技术。6、根据上面提出的方法,将带通型频率选择表面(Frequency Selective Surface, FSS)技术引入到单极子天线带内RCS控制当中,设计了具有低带内RCS特性的单极子天线。分析了低带内RCS单极子天线的辐射和散射特性。通过仿真和实验证明了该天线的良好辐射性能以及带内结构模式项RCS减缩在带内RCS减缩中的应用价值。7、利用对圆极化微带天线RCS控制技术的研究,采用第四章中提出的低RCS圆极化微带天线为阵列单元,设计了具有低RCS特性的圆极化微带阵列天线。对低RCS圆极化阵列天线的辐射和散射特性进行了研究,通过对比参考天线,研究了天线的结构模式项散射以及频域散射特性。最后通过仿真和实验证明该天线的优秀性能。更多还原

【Abstract】 Stealth technique is playing an important role in the modern warfare because the battlefield survivability of the combat platform is greatly affected by its stealth performances. The stealth technique will be applied more and more widely in the future integrated electronic warfare. Antennas are the necessary components on radio equipments such as radars, communication systems and so on. The radio equipments work only if the electromagnetic waves are well transmitted and received by the antennas in the complex battlefield environment. Antennas become one of the most important targets due to their special operating characteristics. One of the most urgent problems in the stealth technique is how to make the antenna invisible to the enemies while maintaining good working performance. Being associated with national research projects, this dissertation focuses on the antenna scattering theory and antenna radar cross section (RCS) control techniques. The antenna RCS control techniques on the ultra wide band (UWB) antenna, circular polarization antenna, monopole antenna and antenna array are studied. The author’s major contributions are outlined as follows:1. The far field expressions of the antenna radiation field are derived and applied on the derivation of the far field expressions of the linear and circular polarization antennas. Expression of the incoming traveling-wave amplitude received by the linear and circular polarization antennas is derived based on the reciprocity theorem. According to the theoretical formulas of the antenna scattering, the scattered field expressions of the linear and circular polarization antennas are also derived. This is the theory foundation of the study on the linear and circular polarization antennas in the following sections.2. Based on the sequence of antenna design and RCS control, a novel method for antenna RCS control is proposed, which designs the antennas according to the radiation and scattering requirements and then compensates the loss of the radiation performance. In the conventional methods a design margin of radiation performance should be made in order to reckon in the deterioration of radiation performance resulted from the RCS reduction. Generally it is difficult to precisely predict the loss of the radiation performance, so it is a big challenge to determine the design margin. However this problem is totally avoided by the novel method proposed by the author.3. According to the new method, a UWB antenna with low RCS level is designed. The radiation and scattering characteristics of the proposed antenna are analyzed. Compared with the reference antenna, the scattering mechanism of the UWB antenna is studied by applying the parameter analysis. At last, the validity of the new method is proved by simulations and measurements.4. Based on the study on the radiation and scattering mechanism of the circular polarization antenna, a novel circular polarization microstrip antenna with low RCS level is designed. The radiation mechanism of the proposed antenna is studied by applying the parameter analysis. And the time and frequency domain characteristics are studied and compared with those of the reference antenna. At last, the radiation and scattering characteristics of the proposed antenna are proved by simulations and measurements.5. According to the frequency of the incoming wave the antenna scattering can be separated into the in-band scattering and out-band scattering. According to the scattering mechanism the antenna scattering can be separated into the antenna mode scattering and structural mode scattering. Based on the two standards above, the antenna scattering can be classified in four related parts: in-band antenna mode scattering, in-band structural mode scattering, out-band antenna mode scattering and out-band structural mode scattering. By the analysis on the difference between the four parts, a novel method for antenna in-band structural mode RCS control is proposed.6. According to the new method, band pass frequency selective surface (FSS) is applied in the monopole antenna in-band RCS control. A monopole antenna with low in-band RCS is designed and its radiation and scattering characteristics are studied. The validity of the new method is proved by simulated and measured results.7. Based on the research on the circular polarization antenna RCS control technique, the low RCS circular polarization antenna proposed in chapter 4 is used in the design of circular polarization array. The radiation and scattering characteristics of the proposed array are studied. The structural mode scattering and frequency domain scattering characteristics are analyzed and compared with thoses of the reference antenna. At last the performances of the proposed array are proved by simulations and measurements.更多还原