面向機電耦合的微波天線隨機與系統(tǒng)誤差的分析與綜合
發(fā)布時間：2018-07-20 17:38
【摘要】：隨著微波天線向著大口徑、高頻段、高增益、高指向精度的方向發(fā)展,機械結構與電磁部分之間的機電耦合問題也越來越突出。本文在機電耦合理論的基礎上,以微波天線中的典型案例一反射面天線和陣列天線為研究對象,系統(tǒng)而定量地研究了隨機和系統(tǒng)誤差對其電性能的影響。建立了計及隨機與系統(tǒng)誤差時反射面天線的平均功率方向圖模型�；陔S機誤差在反射面上呈距離相關性高斯分布的假設,推導出面板加工誤差和與之通過調節(jié)螺栓相連的背架安裝誤差造成的任意兩點相位誤差之差的均值表達式。結合系統(tǒng)誤差導致的饋源軸向偏焦問題,給出了系統(tǒng)誤差存在時錐削照射相關函數(shù)的解析表達式,進而得出了隨機和系統(tǒng)誤差共同作用下的平均功率方向圖模型。以某6.2米口徑反射面天線為例進行了仿真分析,研究了隨機誤差和系統(tǒng)誤差對天線增益、副瓣電平等電性能指標的影響,并給出了有參考價值的結果數(shù)據(jù)和曲線。提出了一種基于面板分塊的加工誤差對反射面天線電性能影響的計算方法。根據(jù)實際反射面天線面板獨立加工制造的特點,把其分成不同環(huán)、同環(huán)不同塊以及同環(huán)同塊三部分。首先計算單塊面板場強的均值,兩兩相乘得到不同塊面板在遠場的平均功率。其次定義了不同位置處加工誤差的相關函數(shù),在單塊面板的面積內完成了同塊面板平均功率的四重數(shù)值積分。最后將三部分的面板功率疊加,得到了整個天線的平均功率,并分析了不同加工精度及分塊方式對反射面天線電性能的影響。提出了一種基于B樣條擬合與Moran's I空間統(tǒng)計分析的組合來診斷反射面天線表面誤差的方法。首先根據(jù)反射面天線為半封閉曲面的特點,確定了反射面的參數(shù)方向以及參數(shù)化方法,然后用u,v兩個方向的B樣條曲線來擬合反射面天線的表面,建立起該確定性曲面的回歸模型。其次基于Moran's I的空間統(tǒng)計方法對該回歸模型的殘差進行空間獨立性分析,分離出隨機誤差和系統(tǒng)誤差。最后,以某3.7m反射面天線為研究對象驗證了該方法的實用性。研究了結構誤差導致的單元極化差異對陣列天線極化特性的影響。以平面陣列天線為研究對象,考慮陣面變形后振子單元位置的偏移和指向的偏轉,得到各單元的局部坐標系。通過三次坐標轉換建立全局到任意局部坐標系變換的統(tǒng)一框架,以此為基礎計算每個單元的全局極化方向圖,進而利用遠場疊加原理得到了天線陣的遠場極化方向圖。以某9×5元面陣為例,仿真得出了相關數(shù)據(jù)和曲線,可為陣列天線的結構設計提供相應的指導�；跈C電耦合理論研究了對數(shù)周期天線結構變形對其電性能的影響。基于對數(shù)周期天線電性能計算方法與結構變形分析,考慮變形后各振子單元激勵電流、位置偏移及指向偏轉的變化,建立了初步的機電耦合模型。基于此模型,研制了集結構、電磁于一體的對數(shù)周期天線機電集成分析軟件平臺,并應用于某4元扇形陣列。
[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.
【學位授予單位】：西安電子科技大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TN822
本文編號：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.
【學位授予單位】：西安電子科技大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TN822
【共引文獻】
相關期刊論文 前2條
1 連培園;王偉;張樹新;楊癸庚;;基于遠場的反射面天線饋源位姿調整方法[J];系統(tǒng)工程與電子技術;2014年01期
2 連培園;段寶巖;王偉;胡乃崗;;遠場反推變形反射面天線饋源調整量[J];西安電子科技大學學報;2014年05期
，本文編號：2134256
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