陶瓷基频率选择表面的设计与制备

发布时间：2018-02-22 01:47

本文关键词： 频率选择表面熔融石英陶瓷高温共烧陶瓷工艺轧膜　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着电磁隐身技术在国防科技领域的迅猛发展,频率选择表面(FSS)天线罩已经逐渐成为关键技术而受到人们越来越多的重视。FSS天线罩不仅起着承载、隔热等作用,还对电磁波进行频率选择,从而有效降低飞行器雷达散射截面(RCS),实现电磁隐身。随着飞行器飞行速度的不断提高,传统有机材料天线罩已经不能适应超高速飞行过程中产生的高温恶劣环境,具有良好透波性能、耐高温、抗热冲击、高机械强度的陶瓷材料成为天线罩材料的热门。而如何成功制备陶瓷基FSS天线罩已经成为超高速飞行器隐身技术的瓶颈。本文在前人基础上对陶瓷基频率选择表面做了相关研究工作。一方面研究了频率选择表面的基本原理以及在天线罩中的应用,成功设计出多种X波段带通型多屏频率选择表面。另一方面以掺杂Li2O-K2O-Al2O3石英陶瓷为原料,并采用高温共烧陶瓷工艺(HTCC)探索平板多屏陶瓷基FSS的制备方法,解决了相关技术难题并获得相关工艺参数。首先,本文对掺杂Li2O-K2O-Al2O3石英陶瓷的性能进行了研究,测试并分析了掺杂石英陶瓷的介电性能、力学性能和热学性能。实验测试证明,该陶瓷介电常数可达4.37,介电损耗0.0038(14GHz),常温下抗弯强度可达163MPa,成功克服了传统石英陶瓷机械强度差的缺点。同时陶瓷结构十分致密,可望具有一定的抗雨蚀砂蚀能力。该材料具有作为天线罩材料的潜力并可与HTCC工艺兼容。其次,本文总结了FSS的基本理论、分类以及应用并设计出多种X波段多屏FSS。本文在传统耶路撒冷十字结构多屏FSS的基础上通过采取改进优化措施如采用封闭环状结构、加载金属枝节等措施成功设计出各具特点的多屏FSS。仿真证明对普通耶路撒冷十字单元加载环状结构可以使FSS具有更小的单元尺寸并提升其入射角度稳定性,消除带外波形畸变并提升带外抑制性能;对FSS单元加载金属枝节能有效降低FSS单元尺寸提升入射角度稳定性;采用新型结构天线-滤波器-天线结构可以产生单边陡降滤波响应,同时使FSS具有较低的剖面,这都是传统FSS所不具有的;采用高阶分形结构FSS具有较好的带外抑制和入射角度稳定性。再次,本文采用掺杂Li2O-K2O-Al2O3石英陶瓷作为原料,并首次采用高温共烧陶瓷工艺(HTCC)制备平板多层FSS,并对各项工艺做了初步的探索,成功解决了轧膜、印刷、等静压、排胶等工艺难题。本文先后采用聚乙酸乙烯酯和PVB作为粘结剂轧膜,并摸索出适合的排胶烧结制度。文章在最后探讨了工艺中常遇到的问题,并分析了可能原因。
[Abstract]:With the rapid development of electromagnetic stealth technology in the field of national defense science and technology, FSS radome has gradually become a key technology and has been paid more and more attention to. FSS radome not only plays a role in carrying capacity and heat insulation, but also plays an important role. In addition, the frequency of electromagnetic wave is selected to effectively reduce the radar cross section (RCS) of aircraft and realize electromagnetic stealth. The traditional organic material radome can not adapt to the high temperature and bad environment produced during the ultra high speed flight, and has good wave permeability, high temperature resistance and thermal shock resistance. Ceramic materials with high mechanical strength have become a hot topic in radome materials. However, how to successfully fabricate ceramic based FSS radome has become the bottleneck of stealthy technology of ultra-high speed aircraft. On the one hand, the basic principle of frequency selective surface and its application in radome are studied. Several X-band band-pass multi-screen frequency-selective surfaces have been successfully designed. On the other hand, using doped Li2O-K2O-Al2O3 quartz ceramics as raw materials, and using high-temperature co-fired ceramics process, the preparation method of FSS based on flat multi-screen ceramics has been explored. At first, the properties of doped Li2O-K2O-Al2O3 quartz ceramics are studied, and the dielectric properties, mechanical properties and thermal properties of doped quartz ceramics are tested and analyzed. The dielectric constant of the ceramic can reach 4.37, the dielectric loss is 0.0038 / 14GHz, and the bending strength can reach 163MPa at room temperature, which successfully overcomes the shortcoming of the mechanical strength of the traditional quartz ceramics, and the structure of the ceramic is very compact. It is expected to have a certain ability to resist rain erosion and sand erosion. This material has the potential as a radome material and can be compatible with HTCC process. Secondly, the basic theory of FSS is summarized in this paper. Classification, application and design of various X-band multi-screen FSs. Based on the traditional Jerusalem cross multi-screen FSS, this paper adopts some improved optimization measures, such as the closed ring structure, The multi-screen FSs with different characteristics are successfully designed by loading metal branches. The simulation results show that loading the annular structure of the common Jerusalem cross elements can make the FSS have smaller unit size and improve the stability of the incident angle. The external wave distortion is eliminated and the out-of-band suppression performance is enhanced, and the stability of the incident angle can be effectively reduced by the addition of metal branches to the FSS unit. Adopting a new structure antenna-filter-antenna structure can produce one-sided steep filtering response and make FSS have a lower profile which is not available in traditional FSS. The high order fractal structure FSS has good stability of out of band suppression and incidence angle. Thirdly, the doped Li2O-K2O-Al2O3 quartz ceramics are used as raw materials. The multilayer FSSs were prepared by high temperature co-fired ceramic process (HTCCC) for the first time, and preliminary exploration was made for each process, which successfully solved the problems of film rolling, printing and isostatic pressing. In this paper, poly (vinyl acetate) and PVB were used as binder to roll the film, and the suitable sintering system was found out. At last, the problems often encountered in the process were discussed, and the possible reasons were analyzed.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN820.81

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