三频段高性能收发共用馈源的研究与设计

发布时间：2018-03-11 01:09

本文选题：多模单脉冲跟踪　切入点：紧凑型自跟踪馈源　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：当代卫星通信业务的发展向地面站天线提出了多频复用、可移动化以及可跟踪等需求。随着Ka频段及更高频段的开发日趋完善,将这些频段与传统通信频段结合的多频段天线可充分地利用卫星通信频谱资源并降低地面站成本。在移动卫星通信的业务中,可跟踪的小型化紧凑型天线成为研究热点。而多频段和自跟踪馈源的研发往往是让卫星通信天线满足这些需求的关键。本文以此为出发点,设计并仿真了Ku频段线极化紧凑型单脉冲馈源、Ku/K双频单脉冲馈源以及X/Ku/Ka三频收发共用馈源。首先,为解决多模单脉冲馈源在线极化跟踪中纵向结构冗长的问题,设计了基于同轴波导的紧凑型半长度TE21模耦合器。该耦合器在保持传统圆波导TE21模耦合器对TE21模耦合以及对其它模式隔离性能的同时,将纵向长度缩减了一半。然后利用同轴波导TE21模与内圆波导TE11模分别传输差模信号与和模、发射信号。再通过轴向扼流环与介质杆的设计,构成了具有和差波束与发射功能的Ku频段线极化自跟踪馈源。由于采用了半长度TE21模耦合器,该馈源纵向结构紧凑。馈源接收和波束与发射波束旋转对称性能良好,结合差波束可实现单脉冲跟踪。其次设计了Ku/K双频单脉冲馈源以实现多频段自跟踪。在Ku频段上利用同轴波导的TE11和TE21模形成双模单脉冲机制进行线极化自跟踪,而在K频段上利用内圆波导TE11和TM01模形成双模单脉冲机制进行圆极化自跟踪。该馈源在两个频段上都具有高等化度的和模波束以及具有轴向零深的差模波束,因此可在两个频段上测量天线增益最大指向与卫星位置的偏差。最后提出了一种X/Ku/Ka三频收发共用馈源方案。X频段的收发双圆极化波先由方波导金属隔板圆极化器形成,再通过矩形波导臂耦合入X/Ku公共同轴波导；Ku频段对同轴波导TE11模收发双线极化馈电由矩形波导开缝耦合完成,并经阶梯变径段过渡到X/Ku公共同轴波导；Ka频段的内圆波导收发双圆极化馈电则通过正交模耦合器和双频螺钉圆极化器完成。X和Ku频段的收发波束由轴向波纹喇叭形成,而Ka频段的收发波束由介质杆形成。该三频段馈源具有稳定的边缘照射电平,可最大限度地扩展卫星通信天线工作频带。
[Abstract]:With the development of satellite communication service, the requirements of multi-frequency multiplexing, removability and traceability have been put forward to earth station antenna. With the development of Ka band and higher frequency band, the development of Ka-band and higher frequency band is becoming more and more perfect. The multiband antenna which combines these bands with the traditional communication band can make full use of the spectrum resources of satellite communication and reduce the cost of earth station. Miniaturized compact antenna with traceability has become a research hotspot, and the research and development of multi-frequency band and self-tracking feed are often the key to satisfy these needs of satellite communication antenna. In order to solve the problem of long longitudinal structure in on-line polarization tracking of multi-mode monopulse feed, we design and simulate the Ku-K dual-frequency monopulse feed and the X / Kur / Ka three-frequency transceiver common feed in Ku band. A compact half-length TE21 mode coupler based on coaxial waveguide is designed, which keeps the traditional circular waveguide TE21 mode coupler from TE21 mode coupling and other modes isolation performance. The longitudinal length is reduced by half. Then the differential mode signal and sum mode are transmitted by using the coaxial waveguide TE21 mode and the inner circular waveguide TE11 mode, respectively. A Ku band line-polarization self-tracking feed with sum difference beam and transmitting function is constructed. Because of the use of half-length TE21 mode coupler, the feed has compact longitudinal structure, and the feed receiving and beam-beam rotating symmetry performance are good. Single pulse tracking can be realized by combining differential beam. Secondly, Ku/K dual-frequency monopulse feed is designed to realize multi-band self-tracking. Linear polarization self-tracking is carried out by using TE11 and TE21 modes of coaxial waveguide to form dual-mode monopulse mechanism in Ku band. On the other hand, the circular polarization self-tracking is carried out by using the dual-mode monopulse mechanism formed by the internal circular waveguide TE11 and TM01 modes in the K band. The feed has a high sum mode beam in both bands and a differential mode beam with axial zero depth. Therefore, it is possible to measure the deviation between the maximum antenna gain direction and the satellite position in two frequency bands. Finally, an X / Ku-K / Ka three-band common feed scheme .X band dual-circular polarization wave is first formed by a square waveguide metal partition circular polarizer. Then the rectangular waveguide arm is coupled to the X / Ku common coaxial waveguide / Ku frequency band to receive and receive dual-line polarization feed of the TE11 mode of the coaxial waveguide, which is accomplished by the rectangular waveguide slit coupling. And the internal circular waveguide transmitting and receiving double circular polarization feed through the step variable diameter section to the X / Ku common coaxial waveguide / Ka band is formed by the axial corrugated horn through the quadrature mode coupler and double frequency screw circular polarizer. The Ka-band beam is formed by a dielectric rod, and the three-band feed has a stable edge radiation level, which can maximize the operational band of the satellite communication antenna.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN927.2

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