含有FSS的磁性复合结构的宽带微波吸收特性

发布时间：2018-04-08 09:15

本文选题：微波吸收　切入点：宽频带　出处：《华中科技大学》2015年硕士论文

【摘要】：由于隐身技术和电子产品的快速发展,人们对高性能吸波材料的需求愈发迫切,尤其是对在限制吸波材料厚度情况下拓展吸收带宽提出了更高的要求。为此,本研究主要开展了由频率选择表面(frequency selective surfaces,FSSs)和磁性贴片组成的磁性复合吸波结构的设计与制备,分析了含有单层和双层FSS的磁性复合结构微波吸收特性,并将其厚度控制在2.2 mm以内,以获得宽带微波吸收磁性复合结构。主要研究结果如下:利用HFSS仿真软件优化设计并制备出基于嵌入加载电阻片FSS宽频带磁性复合结构。首先结合化学刻蚀法和炼胶法分别制备FSS和磁性贴片,然后用同轴法和弓形法分别测试磁性贴片的电磁参数和磁性复合结构微波反射率。结果表明,磁性复合结构反射率测试结果和仿真结果吻合较好。嵌入FSS可以有效改善磁性贴片的吸波性能,尤其是加载电阻的FSS。磁性复合结构从6.1~18 GHz频段可以实现-10 d B以下吸收效果,整体厚度为2 mm。而且在入射角0°~30°和极化角0°~90°(垂直入射)变化时,具有非常好的斜入射和极化稳定性。为了进一步拓展该吸波结构吸收带宽,在上述基础上探讨研究再复合嵌入一层圆环FSS,设计制作了两种典型的基于双层FSS宽频带磁性复合结构,通过仿真和测试分析了其微波吸收性能。测试结果表明,嵌入圆环FSS后,增加了一个低频吸收峰,明显改善了微波低频性能。加入8*8圆环后,反射率在-9 d B以下吸波带宽从6~18 GHz拓宽到4.8~18 GHz。加入12*12圆环后,反射率在-8 d B以下吸收带宽从5.8~18 GHz拓宽到4.3~18 GHz。但是两者整体厚度只增加了0.15 mm,而且嵌入圆环FSS不会影响复合结构良好的极化和斜入射稳定性。开展嵌入FSS的磁性复合结构设计与制备技术,为复合结构吸波材料宽频化设计奠定技术基础和开辟一条可能应用的新途径,有力地拓展了应用前景。
[Abstract]:Due to the rapid development of stealth technology and electronic products, the demand for high performance absorbing materials is becoming more and more urgent, especially for expanding the absorption bandwidth under the condition of limiting the thickness of absorbing materials.Therefore, the design and preparation of magnetic composite absorbing structure composed of frequency selective surface frequency selective surfaces (FSS) and magnetic patch were carried out. The microwave absorption characteristics of magnetic composite structure containing monolayer and double layer FSS were analyzed.In order to obtain the magnetic composite structure of broadband microwave absorption, the thickness is controlled within 2.2 mm.The main results are as follows: a broadband magnetic composite structure based on embedded load resistor FSS is designed and fabricated by HFSS simulation software.FSS and magnetic patch were prepared by chemical etching and gel refining respectively. The electromagnetic parameters and microwave reflectance of magnetic composite structure were measured by coaxial method and bow method respectively.The results show that the reflectivity of the magnetic composite structure is in good agreement with the simulation results.Embedding FSS can effectively improve the absorbing performance of magnetic patch, especially the FSs loaded with resistor.The magnetic composite structure can achieve the absorption effect below -10 dB from 6.1 ~ 18 GHz band, and the overall thickness is 2 mm.Moreover, when the incident angle is 0 掳~ 30 掳and the polarization angle is 0 掳~ 90 掳(vertical incidence), it has very good stability of oblique incidence and polarization.In order to further expand the absorption bandwidth of the absorbing structure, two typical broadband magnetic composite structures based on double-layer FSS are designed and fabricated.The microwave absorption performance is analyzed by simulation and test.The test results show that a low frequency absorption peak is added after the ring FSS is embedded and the microwave low frequency performance is obviously improved.With the addition of 8 rings, the absorption bandwidth below -9 dB can be widened from 6 ~ 18 GHz to 4.8g ~ (18) GHz.The absorption bandwidth below -8 dB was widened from 5.8g ~ (18 GHz) to 4.3g ~ (18) GHz by adding 12 ~ (12) rings.However, the overall thickness of the two rings is only increased by 0. 15 mm, and the embedded ring FSS will not affect the good polarization and oblique incident stability of the composite structure.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM25

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