星载微带阵列天线结构热变形对电性能的影响分析

发布时间：2018-04-21 01:35

  本文选题：星载阵列天线 + 微带天线　； 参考：《西安电子科技大学》2014年硕士论文

【摘要】：星载阵列天线作为空间通信、电子侦察、导航、环境监测等卫星系统的“眼睛”和“耳朵”,通过空间可展开结构实现较大的物理口径,同时克服了传统机械扫描天线的诸多缺点,已成为宇航领域的关键装备之一,具有重要的应用价值和广阔的发展前景。作为星载阵列天线主要形式之一的星载微带阵列天线,受太空恶劣温度环境的影响,微带阵列天线易发生结构热变形。对于低剖面的微带天线而言,结构热变形不仅包括天线单元位置的改变,同时天线单元自身结构也将发生变化。为了分析星载微带阵列天线结构热变形对天线电性能的影响,本文从机电耦合的角度进行研究,主要包括以下内容:首先,阐述星载阵列天线的结构特点和七项关键结构技术,针对典型的X波段、中心频率为10GHz的星载微带天线进行结构建模与优化设计,得到了一副回波损耗大于20dB的星载微带天线单元。然后,针对天线单元,从机电耦合的角度出发,以微带天线单元辐射特性为基础,建立了基于自身结构改变(表面弯曲)的微带天线单元机电耦合模型。通过与电磁软件HFSS仿真结果对比分析,确定其适用范围:对于X波段微带天线单元发生弯曲变形,当变形对应圆心角小于40°时,相对误差满足工程误差小于5%的要求。利用微带天线单元的机电耦合模型分析结构热变形对天线电性能的影响,主要表现为:高温环境下(100℃~120℃),随着温度的升高,热变形量增大,天线电性能逐渐降低,增益最大降低0.21dB;低温环境下(-140℃~-160℃),随着温度的降低,热变形量增大,天线电性能逐渐降低,增益最大降低0.42dB。最后,针对阵列天线,在微带天线单元机电耦合模型的基础上,通过电磁叠加原理,建立了包括天线单元自身结构改变(表面弯曲)、位置偏移和指向偏转的机电耦合模型,并以X波段1×5的线阵为例,分别针对线阵结构无变形和弯曲变形(包括单元表面弯曲、位置变化和指向偏转)两种情况与HFSS软件进行对比验证,验证结果表明机电耦合模型计算结果与电磁软件仿真结果的相对误差满足工程误差小于5%的要求。利用微带阵列天线机电耦合模型分析结构热变形对天线电性能的影响。结构热变形导致天线电性能降低,主要表现为:高温120℃环境下,增益降低0.27dB,副瓣抬高2.07dB,波束指向偏转0.03°;低温-160℃环境下,增益降低0.72dB,副瓣抬高3.98dB,波束指向偏转0.1°;50℃热梯度环境下(20℃~70℃),增益降低0.18dB,副瓣抬高1.17dB,波束指向不变。
[Abstract]:As the "eyes" and "ears" of satellite systems such as space communication, electronic reconnaissance, navigation and environmental monitoring, space-borne array antennas can achieve large physical caliber through space deployable structures. At the same time, it overcomes many shortcomings of the traditional mechanical scanning antenna, and has become one of the key equipment in the field of space navigation, which has important application value and broad development prospect. Spaceborne microstrip array antenna, as one of the main forms of space-borne array antenna, is prone to structural thermal deformation due to the bad temperature environment in space. For the microstrip antenna with low profile, the thermal deformation of the structure includes not only the change of the position of the antenna element, but also the change of the structure of the antenna unit itself. In order to analyze the effect of thermal deformation on the electrical properties of space-borne microstrip array antenna structure, the main contents of this paper are as follows: firstly, the structural characteristics and seven key structural technologies of space-borne microstrip array antenna are described. A typical space-borne microstrip antenna with X-band and 10GHz center frequency is modeled and optimized. A space-borne microstrip antenna unit whose echo loss is greater than 20dB is obtained. Then, based on the radiation characteristics of the microstrip antenna unit, the electromechanical coupling model of the microstrip antenna unit based on its structure change (surface bending) is established from the point of view of electromechanical coupling. By comparing with the simulation results of electromagnetic software HFSS, the applicable range is determined: for X-band microstrip antenna elements, when the corresponding center angle of deformation is less than 40 掳, the relative error can meet the requirement of less than 5% of engineering error. The electromechanical coupling model of microstrip antenna elements is used to analyze the effect of thermal deformation on the electrical properties of the antenna. The main performance of the antenna is as follows: at high temperature, 100 鈩，

本文编号：1780374