基于喇叭单元的平面阵列天线研究

发布时间：2018-01-28 12:04

  本文关键词： 阵列天线 喇叭单元 双极化 双圆极化 低副瓣　出处：《哈尔滨工业大学》2014年博士论文　论文类型：学位论文

【摘要】：近些年,无线电技术发展迅速,近而要求天线电气性能也不断提高。现阶段高容量移动通信系统要求天线具有可便携、低轮廓、重量轻等特性,传统反射面天线形式已经不能满足要求,而平面阵列天线是具有上述特点的天线。本文以当前卫星通信天线、雷达天线工程应用实践为背景,针对天线组阵中的双极化及圆极化特殊实现方法以及低副瓣要求展开研究,结合电磁仿真和试验验证的研究方法,采用喇叭作为基本天线单元优化设计出几种典型的平面阵列天线。(1)为实现双极化、低副瓣平面阵列天线,本文采用探针馈电角锥喇叭作为基本辐射单元,采用低损耗准空气同轴线构建阵列馈电网络,通过无源加权网络实现阵列俯仰面方向图低旁瓣设计,同时结合反相馈电方法提高了天线极化端口隔离度、降低了交叉极化电平。采用阵列周围加载扼流槽的方法实现天线方位面方向图(两单元)低旁瓣、宽波束覆盖设计。实测结果表明:天线交叉极化抑制度大于35d B,两极化端口隔离小于-35d B。该天线的特点:双线极化共口径辐射、极化鉴别度高、结构紧凑。(2)为实现圆极化辐射阵列天线,采用单馈电实现圆极化的方法,优化设计出单臂平面螺旋馈电阶梯喇叭的圆极化辐射单元,分析了辐射单元主要电气参数(辐射方向图、轴比、驻波)的宽频带电磁特性。以单元设计为基础,设计加工了8×8阵列天线。实验结果表明:工作频带内驻波小于1.5,小于3 d B轴比带宽超过23%,交叉极化电平小于-15d B。提出旋转反相馈电方法降低子阵交叉极化电平,样件测试结果与仿真结果吻合,验证了组阵天线设计的正确性。(3)为了突破K波段双圆极化阵列天线技术,本文提出了一种双圆极化波导阵列天线结构,分析设计了高效率共口径双极化辐射单元、宽带圆极化器、低损耗波导馈电网络。测试结果表明:此双圆极化波导阵列天线具有效率高、轴比带宽宽,高隔离度等特点,口面效率大于76%,轴比小于3d B带宽为16.5%,带宽内端口隔离大于25d B,该天线在要求小孔径天线的卫星通信系统中具有很好的工程应用前景。(4)在雷达低副瓣天线技术要求下,提出了一种终端短路馈电形式的角锥喇叭单元形式,以此构建出空气介质填充方形同轴传输线馈电网络自支撑结构的低副瓣阵列天线(16×16)。空气介质填充的同轴线具有损耗低、易加工的特点。利用不等功分网络实现了天线口径的幅度加权,提出加载调谐钉的方法解决了大功分比功分器端口失配的难题。天线样件测试结果表明:驻波小于2的相对带宽为7.5%,中心频点增益为31.8d B,频带内增益大于31.5d B,E面方向图副瓣电平低于-28d B,H面方向图副瓣电平低于-29.5d B。该天线结构紧凑、成本低,具有很高的实用价值。本论文主要工作是针对阵列天线的应用为背景所提出的研究内容,这些研究成果在卫星通信、雷达探测天线系统中具有应用价值。
[Abstract]:In recent years, with the rapid development of radio technology, antenna electrical performance has been improved. At present, high capacity mobile communication system requires antenna to be portable, low profile, light weight and other characteristics. The traditional reflector antenna can not meet the requirements, but the planar array antenna is the antenna with the above characteristics. The background of this paper is the engineering application of satellite communication antenna and radar antenna. Aiming at the special realization method of dual polarization and circular polarization in antenna array and the requirement of low sidelobe, the research method is combined with electromagnetic simulation and experimental verification. In order to realize dual polarization and low sidelobe planar array antenna, the probe fed angle cone horn is used as the basic radiation unit. The low loss quasi-air coaxial line is used to construct the array feed network and the passive weighted network is used to design the low sidelobe of the array pitching plane pattern. At the same time the isolation degree of the antenna polarization port is improved by using the reverse phase feed method. The cross-polarization level is reduced and the low sidelobe of antenna azimuth plane pattern (two elements) is realized by loading choke slot around the array. Design of wide beam coverage. The measured results show that the cross-polarization suppression of the antenna is greater than 35 dB, and the polarization port isolation is less than -35 dB. The characteristics of the antenna are dual-line polarimetric common aperture radiation. In order to realize circular polarization radiation array antenna, the circular polarization radiation unit of single-arm planar helical feeding stepped horn is optimized by using single-fed method to realize circular polarization. The wideband electromagnetic characteristics of the main electrical parameters (radiation pattern, axial ratio, standing wave) of the radiation unit are analyzed, based on the element design. The 8 脳 8 array antenna is designed and fabricated. The experimental results show that the standing wave is less than 1.5 in the operating band, and the bandwidth is less than 3 dB axis ratio over 23%. The cross polarization level is less than -15 dB. A rotating backward phase feed method is proposed to reduce the cross polarization level of the subarray. The test results of the sample are in good agreement with the simulation results. The correctness of array antenna design is verified. (3) in order to break through the K-band dual-circularly polarized array antenna technology, this paper proposes a dual-circularly polarized waveguide array antenna structure. The high efficiency common aperture dual polarization radiation unit, wide band circular polarizer and low loss waveguide feed network are analyzed and designed. The test results show that the dual circular polarization waveguide array antenna has high efficiency and wide axial ratio bandwidth. With high isolation, the efficiency of the interface is greater than 76, the axial ratio is less than 3 dB, the bandwidth is 16. 5 and the isolation of the ports in the bandwidth is greater than 25 dB. The antenna has a good prospect of engineering application in the satellite communication system which requires small aperture antenna.) under the technical requirements of radar low sidelobe antenna. In this paper, a new type of angular cone horn unit is proposed, in which the terminal short circuit is fed. A low sidelobe array antenna with self-supporting structure of air dielectric filled square coaxial transmission line feed network is constructed. The coaxial line filled with air medium has low loss. The amplitude weighting of antenna aperture is realized by using unequal power distribution network. The method of loading tuning nail is proposed to solve the problem of power divider port mismatch. The test results of antenna sample show that the relative bandwidth of standing wave less than 2 is 7.5 and the gain of center frequency is 31.8 dB. The sidelobe level of the pattern pattern is lower than that of -28 dB / H plane pattern with a gain greater than 31.5 d / d, which is lower than -29.5 dB. The antenna is compact in structure and low in cost. The main work of this thesis is the application of array antenna in the background. These research results have application value in satellite communication and radar detection antenna system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN820.15
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本文编号：1470710