多波束反射面天线的研究与设计

发布时间：2018-09-03 06:36

【摘要】：本文针对Ku波段的多波束抛物反射面天线进行了研究与设计,利用在反射面的焦平面上放置多个馈源的方法来实现天线多波束的功能,并结合Ku波段角分集散射通信对多波束天线的要求,提出了在反射面的焦点位置处尽可能近的放置多个独立馈源,且馈源之间的波束相关性比较小,就可以将小尺寸的反射面天线应用在角分集通信技术中的研究方案。在具体的设计中,通过对比介质杆天线与普通喇叭天线在尺寸和性能上的优劣,从小型化的角度出发选择介质杆天线作为系统馈源并对介质杆天线进行性能优化。接着对正交模耦合器进行设计以实现天线的收发隔离,并将介质杆天线与正交模耦合器级联在一起作为反射面天线的双极化馈源,最终优化了双极化介质杆天线电压驻波比、端口隔离度、最大方向增益、半功率波瓣宽度等性能参数,实现系统对馈源的设计指标要求。将双极化介质杆天线作为反射面系统的馈源,首先利用单馈源对抛物反射面天线的辐射特性进行研究与分析,根据指标要求确定反射面的口径与焦径比以及馈源的位置,接着对馈源进行组阵以实现反射面天线的多波束性能,并针对馈源组阵后由于介质杆之间的电磁耦合导致的增益下降、波束偏移角变大等问题提出利用金属隔板减小互耦的方案,优化设计了双波束双极化组合馈源。天线整体仿真中,研究了馈源支撑结构对反射面天线极化性能的影响。经过研究与优化设计,在工作频段内,该双波束反射面天线各极化端口的驻波不高于1.5,不同端口之间的隔离度不低于30dB,各波束的增益不低于45dB,各波束的交叉极化隔离度不低于35dB,对称波束之间的波束夹角为0.75倍波瓣宽度。实现了小尺寸、双独立波束、高增益、窄波束夹角、低交叉极化电平,在对流层通信角分集技术中有一定的应用价值。
[Abstract]:In this paper, the multi-beam parabolic reflector antenna in Ku band is studied and designed. The function of multi-beam antenna is realized by placing multiple feeders on the focal plane of the reflector. Considering the requirements of Ku band angular diversity scattering communication for multi-beam antennas, it is proposed that multiple independent feeds be placed as close as possible to the focal point of the reflector, and the beam correlation between the feeders is small. The small reflector antenna can be applied to the research of angular diversity communication technology. In the specific design, by comparing the size and performance of the dielectric rod antenna and the ordinary horn antenna, the dielectric rod antenna is selected as the feed of the system from the miniaturization point of view, and the performance of the dielectric rod antenna is optimized. Then the orthogonal mode coupler is designed to realize the antenna receiving and receiving isolation, and the dielectric rod antenna and the orthogonal mode coupler are cascaded together as the dual polarization feed of the reflector antenna. Finally, the voltage standing wave ratio of the double polarization dielectric rod antenna is optimized. The performance parameters, such as port isolation, maximum directional gain and half-power lobe width, are used to meet the design requirements of the system. The dual polarization dielectric rod antenna is used as the feed of the reflector system. Firstly, the radiation characteristics of the parabolic reflector antenna are studied and analyzed by using the single feed source. The aperture to focal diameter ratio of the reflector surface and the position of the feed are determined according to the requirements of the index. Then the feed array is carried out to realize the multi-beam performance of the reflector antenna, and the gain decreases due to the electromagnetic coupling between the dielectric rods after the feed array. A scheme of reducing mutual coupling by metal separator is proposed to optimize the design of dual-beam dual-polarization combined feed. In the whole antenna simulation, the effect of feed support structure on the polarization performance of reflector antenna is studied. After studying and optimizing design, in the working frequency band, The standing wave of each polarization port of the dual beam reflector antenna is not more than 1.5, the isolation between different ports is not less than 30 dB, the gain of each beam is not less than 45 dB, the cross-polarization isolation of each beam is not less than 35 dB, and the beam clamp between symmetric beams is not less than 35 dB. The angle is 0.75 times the width of the lobe. Small size, dual independent beam, high gain, narrow beam angle and low cross-polarization level are realized. It has certain application value in tropospheric communication angle diversity technology.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN823.27

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