基于印刷辐射元的纺织复合材料天线的制备及其性能研究

发布时间：2018-08-25 14:06

【摘要】：随着科技的不断进步,复合材料经历了从小到大,由次到主,由结构到功能的发展道路。特别是航空航天领域,复合材料在飞机结构上应用不仅仅是减轻重量,提高比强度,而是应该通过合理的设计使其兼具力学性能和功能性等多方面的价值。针对传统的突出配置结构的天线,如何在不破坏机体机械性能的同时降低天线的剖面将有助于提高飞行器的机动性能和效率；而在薄介质基体上增加天线的带宽也成为了人们关注的另一个焦点。在天线与复合材料有效的结合过程中,复合材料的结构和成型方式至关重要。本课题采用印刷方式来制作复合材料天线,利用真空辅助树脂转移成型工艺将辐射单元,介质基体和天线地板一体成型,同时运用开槽技术提高矩形微带天线的带宽。针对上述研究,具体相关内容如下：(1)首先对采用真空辅助树脂转移成型工艺制作的玻纤天线基板的介电性能进行了充分的研究,结果表明本文设计的天线基板的介电常数3.763,介电损耗角正切为0.01。根据介电性能的测试结果结合天线的理论分析方法,设计了矩形和开槽两种微带天线。仿真结果表明,在设计频率为1.575GHz的频率下,矩形微带天线回波损耗为-37.65dB,增益为4.52dB,天线方向图和史密斯圆图表明天线的辐射性能和阻抗匹配良好。而开槽天线在同样的频率下,回波损耗为-15.12dB,增益为3.18dB,方向性和阻抗匹配满足要求。但是开槽天线的带宽比矩形天线带宽增加了132.5%,而天线面积减少了39.5%。(2)根据上述天线的尺寸设计参数,分别以铜箔和银浆两种材料为辐射单元制作了四款天线即矩形铜箔微带天线,矩形银浆微带天线,开槽铜箔微带天线和开槽银浆微带天线。其中银浆辐射元采用丝网印刷工艺,该工艺具有适印性好,精确度高,成本低等特点。天线的辐射单元,介质基体和地板整体采用真空辅助树脂转移成型工艺成型,最后通过合理设计的焊接工艺得到四款天线。(3)四款天线电磁参数实测表明,在中心频率为1.575GHz的频率下,矩形铜箔,矩形银浆,开槽铜箔和开槽银浆微带天线的回波损耗分别为-13.8dB,-18.9dB,-12.6dB和-16.8dB,所有天线基本在0°方向都具有最大的辐射性能。但是相比传统铜箔材质,导电银浆材质的天线回波损耗更小,阻抗匹配更佳,而且方向图结果同仿真结果重合率更好。在满足回波损耗小于-10dB的条件下,开槽银浆天线相比矩形银浆天线带宽增加了271%,天线方向图的主瓣和后瓣也显示了良好的方向性。(4)机械性能作为复合天线的重要性能,本文分别分析了铜箔和银浆两种材质辐射单元天线的拉伸性能和弯曲性能。机械性能结果显示银浆天线的归一化拉伸强度比铜箔天线提高了9.9%,同时银浆天线归一化弯曲强度比铜箔天线提高了19.3%,银浆辐射元可以提高天线的机械性能。(5)最后通过观察天线辐射元与介质表面的结合性以及拉伸、弯曲断裂面的扫描电镜照片,从微观角度解释了印刷银浆辐射元同基体的结合性能更好。纤维断裂面整齐规则,从微观角度表明了银浆天线机械性能较高。综上所述,本文采用丝网印刷工艺成功制备了复合材料天线,力学和电学性能都比铜箔天线有所提高。开槽天线的设计和实现,使得拓宽微带天线的带宽在薄介质基体板上成为可能,这进一步增加了天线的适用环境,且制得的天线更加轻薄。采用导电浆料辐射单元和纺织品的结合,使得本课题的研究方法为智能化,多功能化的复合材料提供了一个新的思路。
[Abstract]:With the continuous progress of science and technology, composite materials have experienced a development path from small to large, from secondary to primary, from structure to function. Especially in the field of aerospace, the application of composite materials in aircraft structures is not only to reduce weight and improve specific strength, but also to make them have both mechanical properties and functional properties through reasonable design. Value. For the traditional antenna with prominent configuration, how to reduce the profile of the antenna while not destroying the mechanical properties of the body will help to improve the maneuverability and efficiency of the aircraft; and how to increase the bandwidth of the antenna on a thin dielectric substrate has become another focus of attention. In this paper, the composite antenna is fabricated by printing method, the radiation unit, the dielectric matrix and the antenna floor are formed by vacuum assisted resin transfer molding technology, and the bandwidth of the rectangular microstrip antenna is improved by slotting technology. The main contents are as follows: (1) Firstly, the dielectric properties of glass fiber antenna substrate fabricated by vacuum assisted resin transfer molding process are studied. The results show that the dielectric constant of the antenna substrate is 3.763 and the dielectric loss tangent is 0.01. The simulation results show that the return loss of the rectangular microstrip antenna is - 37.65 dB and the gain is 4.52 dB at the design frequency of 1.575 GHz. The radiation performance and impedance of the antenna pattern and Smith circle are well matched. The return loss of the slotted antenna is - 15.12 dB at the same frequency. The gain is 3.18dB, and the directivity and impedance matching meet the requirements. However, the bandwidth of slotted antenna is 132.5% larger than that of rectangular antenna, and the antenna area is reduced by 39.5%. (2) According to the size design parameters of the antenna, four kinds of rectangular copper-foil microstrip antennas, rectangular silver-foil microstrip antennas and copper-silver-foil microstrip antennas are fabricated. Slurry microstrip antenna, slotted copper foil microstrip antenna and slotted silver paste microstrip antenna. Silver paste radiation element adopts screen printing process, which has good printability, high accuracy, low cost and other characteristics. The radiation element of antenna, dielectric matrix and floor are formed by vacuum assisted resin transfer molding process, and finally through reasonable design. Four antennas were obtained by welding process. (3) The measured electromagnetic parameters of the four antennas show that the return losses of the rectangular copper foil, rectangular silver paste, slotted copper foil and slotted silver paste microstrip antennas are - 13.8 dB, - 18.9 dB, - 12.6 dB and - 16.8 dB respectively at the center frequency of 1.575 GHz. All the antennas have the greatest radiation performance in the direction of 0 degrees. Compared with the traditional copper foil material, the antenna with conductive silver paste has smaller echo loss, better impedance matching and better coincidence rate with the simulation results. (4) As an important performance of the composite antenna, the tensile and bending properties of the silver paste antenna are analyzed. The results show that the normalized tensile strength of the silver paste antenna is 9.9% higher than that of the copper foil antenna, and the normalized bending strength of the silver paste antenna is 9.9% higher than that of the copper paste antenna. The foil antenna is improved by 19.3%. The silver paste element can improve the mechanical properties of the antenna. (5) Finally, the combination of the antenna element with the dielectric surface and the tensile and bending fracture surface are observed by scanning electron microscopy. The bonding performance of the silver paste element with the substrate is better explained from the microscopic point of view. The angle indicates that the silver paste antenna has higher mechanical properties. In summary, the composite antenna has been successfully fabricated by screen printing process. The mechanical and electrical properties of the composite antenna are better than those of the copper foil antenna. The design and implementation of slotted antenna make it possible to widen the bandwidth of the microstrip antenna on the thin dielectric substrate, which further increases the bandwidth of the microstrip antenna. The combination of conductive paste radiation unit and textile provides a new idea for intelligent and multi-functional composite materials.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN820;TB33

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