Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher sur...Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher surface accuracy. However, low accuracy and low effi- ciency are the common disadvantages for traditional panel alignment and adjustment. In order to improve the surface accuracy of large reflector antenna, a new method is pre- sented to determinate panel adjustment values from far field pattern. Based on the method of Physical Optics （PO）, the effect of panel facet displacement on radiation field value is derived. Then the linear system is constructed between panel adjustment vector and far field pattern. Using the method of Singular Value Decomposition （SVD）, the adjustment value for all panel adjustors are obtained by solving the linear equations. An experiment is conducted on a 3.7 m reflector antenna with 12 segmented panels. The results of simulation and test are similar, which shows that the presented method is feasible. Moreover, thediscussion about validation shows that the method can be used for many cases of reflector shape. The proposed research provides the instruction to adjust surface panels efficiently and accurately.展开更多
针对大型分块反射面天线面板调整次数多、效率低的问题,提出了一种从天线远场方向图反推出面板调整量进而快速调整的方法。应用物理光学(physical optics,PO)法建立了表面节点位移与远区电场的线性关系,将面板调整向量与远区辐射场强用...针对大型分块反射面天线面板调整次数多、效率低的问题,提出了一种从天线远场方向图反推出面板调整量进而快速调整的方法。应用物理光学(physical optics,PO)法建立了表面节点位移与远区电场的线性关系,将面板调整向量与远区辐射场强用线性方程组联系起来。利用奇异值分解(singular value decomposition,SVD)法求解线性方程组得调整向量,从而实现由方向图反推调整量的目的。对某工程案例进行了分析计算,给出了相应的数据与曲线,证明了所提方法的有效性,为大型天线反射面板的精确调整提供了指导。展开更多
Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineeri...Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51490661,51490660,51205301)National Key Basic Research Program of China(973 Program,Grant No.2015CB857100)Special Funding for Key Laboratory of Xinjiang Uygur Autonomous Region,China(Grant No.2014KL012)
文摘Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher surface accuracy. However, low accuracy and low effi- ciency are the common disadvantages for traditional panel alignment and adjustment. In order to improve the surface accuracy of large reflector antenna, a new method is pre- sented to determinate panel adjustment values from far field pattern. Based on the method of Physical Optics （PO）, the effect of panel facet displacement on radiation field value is derived. Then the linear system is constructed between panel adjustment vector and far field pattern. Using the method of Singular Value Decomposition （SVD）, the adjustment value for all panel adjustors are obtained by solving the linear equations. An experiment is conducted on a 3.7 m reflector antenna with 12 segmented panels. The results of simulation and test are similar, which shows that the presented method is feasible. Moreover, thediscussion about validation shows that the method can be used for many cases of reflector shape. The proposed research provides the instruction to adjust surface panels efficiently and accurately.
文摘针对大型分块反射面天线面板调整次数多、效率低的问题,提出了一种从天线远场方向图反推出面板调整量进而快速调整的方法。应用物理光学(physical optics,PO)法建立了表面节点位移与远区电场的线性关系,将面板调整向量与远区辐射场强用线性方程组联系起来。利用奇异值分解(singular value decomposition,SVD)法求解线性方程组得调整向量,从而实现由方向图反推调整量的目的。对某工程案例进行了分析计算,给出了相应的数据与曲线,证明了所提方法的有效性,为大型天线反射面板的精确调整提供了指导。
基金supported by the National Key Research and Development Program of China (Grant No. 2021YFC2203600)National Natural Science Foundation of China (Grant Nos. 52005377 and 51975447)+1 种基金Youth Innovation Team of Shaanxi Universities (Grant No. 201926)Fundamental Research Funds for the Central Universities (Grant Nos. JB210404 and JB210403)。
文摘Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.
