雷达罩频率选择表面的设计及激光精密加工技术研究

发布时间：2018-08-14 12:05

【摘要】：频率选择表面(Frequency Selective Surfaces,FSS),是一种由许多无源的谐振单元二维周期性排列构成的单层或者多层平面结构。FSS对电磁波和光波具有一定的频率选择特性,在金属薄膜上刻蚀二维周期性孔径单元或粘贴金属贴片单元,形成“电振子结构”,从而对电磁波具有按频率呈现带通(开孔型)或带阻(贴片型)的特性。FSS和雷达罩复合可以形成FSS雷达罩,能够有效减小空天飞行器的雷达散射截面(RCS),对空天飞行器的雷达隐身有重要意义。本文以二维平面、规则曲面、复杂曲面等多种结构型式雷达罩FSS的设计仿真及高精度高效率加工技术为研究目标,开展了较为系统的雷达罩FSS设计与投影式激光精密加工技术研究。首先,讨论了影响平面FSS设计的主要因素和模型设计方法,分析了几何尺寸设计参数和平面波入射角度θ对其电磁滤波特性的影响关系,采用时域有限积分法进行仿真计算,获得了其表面电场分布、近场能量分布等表征参量。其次,针对可展性规则曲面雷达罩,采用了一种极具工程实用性的直接贴覆式规则曲面雷达罩FSS设计与建模仿真方法。详细阐述了时域积分理论算法对于曲面FSS仿真的适应性积分模型和改进方程,基于时域有限积分法仿真分析了圆环缝隙型柱面和锥面共形FSS的传输特性曲线及RCS缩减特性。再次,提出了一种直接基于在线测量点云数据对复杂曲面工件进行建模与共形周期性图形布局一体化方法,并且基于CATIA软件实现了实例仿真。利用时域有限积分法(FITD)对复杂曲面Y孔FSS雷达罩进行全波仿真分析,同时引入阵列导引头相控阵天线,深入研究了复杂曲面Y孔FSS雷达罩的宽带透波率和瞄准误差,结果表明这种新的复杂曲面雷达罩FSS建模与布局设计方法是一种完全可行的工程化方法。最后,介绍了平行投影式振镜扫描(PPGS)激光精密刻蚀加工技术的原理及工艺流程,并基于课题组自主研发的PPGS激光精密加工设备,试验加工了平面、柱面和锥面雷达罩FSS样品,分析了刻蚀边界显微轮廓及SEM微观结构,测试了其传输特性曲线。结果表明PPGS激光精密加工技术可以兼容平面、规则曲面及复杂曲面雷达罩FSS的加工制造,是解决大型复杂曲面雷达罩FSS的高效率、“跨尺度”加工制造的可行技术方案。
[Abstract]:Frequency selective surface (Frequency Selective surfaces) is a single-layer or multi-layer planar structure composed of many passive resonant units arranged periodically in two dimensions. FSs has certain frequency selective characteristics for electromagnetic and optical waves. Etching two-dimensional periodic aperture units or sticking metal patch elements on metal thin films to form an "electric oscillator structure", Thus, the FSS radome can be formed by the combination of band pass (open hole type) or band stop (patch type) for electromagnetic wave. It is very important to reduce radar cross section (RCS),) of aircrafts effectively. The aim of this paper is to design and emulate the FSS of radar radome with two dimensional plane, regular surface, complex surface, and high precision and high efficiency machining technology. The FSS design of radar radome and the research of projective laser precision machining technology are carried out. Firstly, the main factors affecting the design of planar FSS and the method of model design are discussed. The influence of geometric dimension design parameters and incident angle 胃 of plane wave on the electromagnetic filtering characteristics is analyzed. The finite integration time domain method is used to simulate and calculate. The surface electric field distribution and near field energy distribution were obtained. Secondly, aiming at the developable regular surface radome, a method of FSS design, modeling and simulation of direct-pasted regular curved surface radome is adopted. The adaptive integral model and improved equation of time-domain integral theory algorithm for curved surface FSS simulation are described in detail. Based on the finite integration time domain method, the transmission characteristic curves and RCS reduction characteristics of circular slot cylindrical and conical conformal FSS are simulated and analyzed. Thirdly, an integration method of modeling and conformal periodic graphic layout of complex surface workpieces based on on-line measurement point cloud data is proposed, and an example simulation is implemented based on CATIA software. The full wave simulation analysis of complex curved Y-hole FSS radome is carried out by using the finite integration time domain (FITD) method. At the same time, the wide-band transmittance and aiming error of complex curved Y-hole FSS radome are studied by introducing the array seeker phased array antenna. The results show that the new FSS modeling and layout design method for complex curved radome is a feasible engineering method. Finally, the principle and technological process of parallel projection mirror scanning (PPGS) laser precision etching technology are introduced. Based on the PPGS laser precision machining equipment developed by our research group, the plane, cylinder and cone surface radar cover FSS samples are experimentally processed. The microstructure of etching boundary and the microstructure of SEM are analyzed and the transmission characteristic curves are measured. The results show that the PPGS laser precision machining technology can be compatible with the manufacture of FSS for plane, regular surface and complex surface radome. It is a feasible technical scheme to solve the problem of high efficiency and "cross scale" processing and manufacturing of large complex surface radome FSS.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN957;TN249

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