面向机电耦合的微波天线随机与系统误差的分析与综合
发布时间：2018-07-20 17:38
【摘要】：随着微波天线向着大口径、高频段、高增益、高指向精度的方向发展,机械结构与电磁部分之间的机电耦合问题也越来越突出。本文在机电耦合理论的基础上,以微波天线中的典型案例一反射面天线和阵列天线为研究对象,系统而定量地研究了随机和系统误差对其电性能的影响。建立了计及随机与系统误差时反射面天线的平均功率方向图模型。基于随机误差在反射面上呈距离相关性高斯分布的假设,推导出面板加工误差和与之通过调节螺栓相连的背架安装误差造成的任意两点相位误差之差的均值表达式。结合系统误差导致的馈源轴向偏焦问题,给出了系统误差存在时锥削照射相关函数的解析表达式,进而得出了随机和系统误差共同作用下的平均功率方向图模型。以某6.2米口径反射面天线为例进行了仿真分析,研究了随机误差和系统误差对天线增益、副瓣电平等电性能指标的影响,并给出了有参考价值的结果数据和曲线。提出了一种基于面板分块的加工误差对反射面天线电性能影响的计算方法。根据实际反射面天线面板独立加工制造的特点,把其分成不同环、同环不同块以及同环同块三部分。首先计算单块面板场强的均值,两两相乘得到不同块面板在远场的平均功率。其次定义了不同位置处加工误差的相关函数,在单块面板的面积内完成了同块面板平均功率的四重数值积分。最后将三部分的面板功率叠加,得到了整个天线的平均功率,并分析了不同加工精度及分块方式对反射面天线电性能的影响。提出了一种基于B样条拟合与Moran's I空间统计分析的组合来诊断反射面天线表面误差的方法。首先根据反射面天线为半封闭曲面的特点,确定了反射面的参数方向以及参数化方法,然后用u,v两个方向的B样条曲线来拟合反射面天线的表面,建立起该确定性曲面的回归模型。其次基于Moran's I的空间统计方法对该回归模型的残差进行空间独立性分析,分离出随机误差和系统误差。最后,以某3.7m反射面天线为研究对象验证了该方法的实用性。研究了结构误差导致的单元极化差异对阵列天线极化特性的影响。以平面阵列天线为研究对象,考虑阵面变形后振子单元位置的偏移和指向的偏转,得到各单元的局部坐标系。通过三次坐标转换建立全局到任意局部坐标系变换的统一框架,以此为基础计算每个单元的全局极化方向图,进而利用远场叠加原理得到了天线阵的远场极化方向图。以某9×5元面阵为例,仿真得出了相关数据和曲线,可为阵列天线的结构设计提供相应的指导。基于机电耦合理论研究了对数周期天线结构变形对其电性能的影响。基于对数周期天线电性能计算方法与结构变形分析,考虑变形后各振子单元激励电流、位置偏移及指向偏转的变化,建立了初步的机电耦合模型。基于此模型,研制了集结构、电磁于一体的对数周期天线机电集成分析软件平台,并应用于某4元扇形阵列。
[Abstract]:As the microwave antenna is developing in the direction of large aperture, high frequency, high gain and high pointing precision, the electromechanical coupling problem between the mechanical structure and the electromagnetic part is becoming more and more prominent. On the basis of the electromechanical coupling theory, this paper takes the typical case of the microwave antenna, the reflector antenna and the array antenna as the research object, and systematically and quantitatively. The influence of random and systematic error on its electrical performance is studied. An average power pattern model of the reflector antenna with random and systematic errors is established. Based on the assumption that the random error has a distance correlation Gauss distribution on the reflector, the machining error of the panel and the installation error of the back frame connected to the regulating bolt are derived. The mean expression of the difference in the error of any two point phase is combined with the problem of the axial deflection of the feed source caused by the system error. The analytic expression of the correlation function of the taper illumination when the system error exists is given, and then the average power square graph model under the joint action of the random and the system error is obtained. A 6.2 meter aperture reflector antenna is given. The effect of random error and system error on the antenna gain, the sidelobe level and other electrical performance indexes is studied, and the result data and curves with reference value are given. A method for calculating the electrical performance of the reflector antenna based on the processing error of the panel block is proposed. The characteristics of independent manufacturing are divided into different rings, different blocks of the same ring and three parts of the same ring block. First, the mean of the field strength of the single panel is calculated, and the average power of the different block panels in the far field is obtained by 22. Secondly, the correlation function of the machining error at different positions is defined, and the same block panel is completed within the area of the single panel. The four weight integral of the average power is obtained. Finally, the power of the three part of the panel is superimposed, the average power of the whole antenna is obtained. The influence of the different processing precision and the block mode on the electrical performance of the reflector antenna is analyzed. A combination of B spline fitting and the Moran's I spatial statistical analysis is proposed to diagnose the surface error of the reflector antenna. According to the characteristics of the reflector antenna as a semi closed surface, the parameter direction and the parameterization method of the reflector surface are determined. Then the surface of the reflector antenna is fitted with the B spline curve of the two directions of u and V, and the regression model of the deterministic surface is established. Secondly, the regression model based on the spatial statistics method based on Moran's I is used. The spatial independence of the type is analyzed and the random error and the system error are separated. Finally, the practicability of the method is verified by a 3.7m reflector antenna. The influence of the polarization difference on the polarization characteristics of the array antenna caused by the structural error is studied. The partial coordinate system of each element is obtained by the displacement of the location of the oscillator unit and the directional deflection of the unit. A unified framework of the global to any local coordinate transformation is established by three coordinate transformation, and the global polarization direction of each unit is calculated based on this, and the far-field polarization direction of the antenna array is obtained by the superposition of the far field. As an example of 9 x 5 element array, the related data and curves are obtained, which can provide the corresponding guidance for the structure design of the array antenna. Based on the electromechanical coupling theory, the influence of the structural deformation of the logarithmic periodic antenna on its electrical performance is studied. A preliminary electromechanical coupling model is established for the change of excitation current, position shift and directional deflection. Based on this model, a software platform for the electromechanical integration analysis of a logarithmic periodic antenna with a set of structures and electromagnetic fields is developed and applied to a 4 element sector array.
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN822
本文编号：2134256
[Abstract]:As the microwave antenna is developing in the direction of large aperture, high frequency, high gain and high pointing precision, the electromechanical coupling problem between the mechanical structure and the electromagnetic part is becoming more and more prominent. On the basis of the electromechanical coupling theory, this paper takes the typical case of the microwave antenna, the reflector antenna and the array antenna as the research object, and systematically and quantitatively. The influence of random and systematic error on its electrical performance is studied. An average power pattern model of the reflector antenna with random and systematic errors is established. Based on the assumption that the random error has a distance correlation Gauss distribution on the reflector, the machining error of the panel and the installation error of the back frame connected to the regulating bolt are derived. The mean expression of the difference in the error of any two point phase is combined with the problem of the axial deflection of the feed source caused by the system error. The analytic expression of the correlation function of the taper illumination when the system error exists is given, and then the average power square graph model under the joint action of the random and the system error is obtained. A 6.2 meter aperture reflector antenna is given. The effect of random error and system error on the antenna gain, the sidelobe level and other electrical performance indexes is studied, and the result data and curves with reference value are given. A method for calculating the electrical performance of the reflector antenna based on the processing error of the panel block is proposed. The characteristics of independent manufacturing are divided into different rings, different blocks of the same ring and three parts of the same ring block. First, the mean of the field strength of the single panel is calculated, and the average power of the different block panels in the far field is obtained by 22. Secondly, the correlation function of the machining error at different positions is defined, and the same block panel is completed within the area of the single panel. The four weight integral of the average power is obtained. Finally, the power of the three part of the panel is superimposed, the average power of the whole antenna is obtained. The influence of the different processing precision and the block mode on the electrical performance of the reflector antenna is analyzed. A combination of B spline fitting and the Moran's I spatial statistical analysis is proposed to diagnose the surface error of the reflector antenna. According to the characteristics of the reflector antenna as a semi closed surface, the parameter direction and the parameterization method of the reflector surface are determined. Then the surface of the reflector antenna is fitted with the B spline curve of the two directions of u and V, and the regression model of the deterministic surface is established. Secondly, the regression model based on the spatial statistics method based on Moran's I is used. The spatial independence of the type is analyzed and the random error and the system error are separated. Finally, the practicability of the method is verified by a 3.7m reflector antenna. The influence of the polarization difference on the polarization characteristics of the array antenna caused by the structural error is studied. The partial coordinate system of each element is obtained by the displacement of the location of the oscillator unit and the directional deflection of the unit. A unified framework of the global to any local coordinate transformation is established by three coordinate transformation, and the global polarization direction of each unit is calculated based on this, and the far-field polarization direction of the antenna array is obtained by the superposition of the far field. As an example of 9 x 5 element array, the related data and curves are obtained, which can provide the corresponding guidance for the structure design of the array antenna. Based on the electromechanical coupling theory, the influence of the structural deformation of the logarithmic periodic antenna on its electrical performance is studied. A preliminary electromechanical coupling model is established for the change of excitation current, position shift and directional deflection. Based on this model, a software platform for the electromechanical integration analysis of a logarithmic periodic antenna with a set of structures and electromagnetic fields is developed and applied to a 4 element sector array.
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN822
【共引文献】
相关期刊论文 前2条
1 连培园;王伟;张树新;杨癸庚;;基于远场的反射面天线馈源位姿调整方法[J];系统工程与电子技术;2014年01期
2 连培园;段宝岩;王伟;胡乃岗;;远场反推变形反射面天线馈源调整量[J];西安电子科技大学学报;2014年05期
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