高次模基片集成腔毫米波阵列天线原理与制备关键技术

Low-temperature co-fired ceramic (LTCC) technology provides technical support for miniaturization of antenna with its advantages of multi-layer structure. The millimeter-wave array antenna manufactured by LTCC technology has become research hotspot with its advantages of small volume, high integration, light weight, low cost, etc. A substrate integrated cavity (SIC) millimeter-wave array antenna operating in its high-order mode is proposed in this project. The adjustment of field distribution of the high-order mode in the SIC and the reconstruction of the radiation pattern will be studied and adopted to achieve full use of the limited area for each array element and to increase the gain of the array element; then, through the research on the mutual coupling between the SIC radiating element and its inhibition method, as well as the effect of the SIC dimensions on the radiation performance of the SIC array, the total gain of array will be significantly improved. At the same time, in order to solve the problem of millimeter-wave dielectric performance testing of the ceramic materials, a testing platform based on the Fabry-Perot resonator theory will be set up in this project, and on this basis the improvement of millimeter-wave LTCC-process adaptability of BaAl2Si2O8-based ceramic materials will be studied to obtain the millimeter-wave LTCC substrate materials with excellent electrical performance and independent intellectual property rights. Finally, through the research in this project, independent design and localization of the preparation of high-gain millimeter-wave LTCC array antenna should be achieved.

低温共烧陶瓷（LTCC）技术凭借其多层结构的优势为实现天线的小型化提供了技术支撑，采用LTCC技术制成的毫米波阵列天线具有体积小、集成度高、重量轻、成本低等优点，成为国内外研究热点。本项目提出了一种工作于高次模的基片集成腔毫米波阵列天线，通过对基片集成腔中高次模场分布的调整及其辐射方向图的重构，实现充分利用有限阵列天线单元面积，提升阵列单元天线的增益，并结合对基片集成腔辐射单元间互耦产生机理及其抑制方法以及基片集成腔辐射口径尺寸对阵列天线整体性能影响的研究，实现阵列天线增益的显著提高；同时，为了解决介质材料毫米波频段介电性能测试的难题，项目拟搭建基于法布里-珀罗谐振腔原理的W波段材料介电性能测试平台，在此基础上开展BaAl2Si2O8基陶瓷材料的毫米波LTCC工艺适配性改进研究，获得电性能优良、具有自主知识产权的毫米波用LTCC基板材料，实现高增益毫米波阵列天线的自主设计与国产化制备

针对毫米波通信领域对小型化高增益天线及其低介电常数LTCC国产化材料的迫切需求，本项目开展了高次模基片集成腔辐射结构及其阵列天线设计、W波段材料介电性能测试表征方法和BaAl2Si2O8体系材料LTCC工艺适配性改进等三方面的研究工作。本项目通过对基片集成腔辐射结构内部电场及谐振模式分析，掌握了高次模基片集成腔的辐射机理与设计方法，结合基片集成波导立体馈电网络的研究，设计并制备了W波段4×4单元宽带、高增益阵列天线，天线-10dB阻抗带宽为81.45–97.05GHz，增益高达20.3dBi。本项目还面向实际需求，设计出了满足毫米波汽车雷达应用的宽带、高增益、低副瓣线极化阵列天线和双极化阵列天线；针对卫星通讯应用，设计出了宽带、高增益基片集成腔圆极化阵列天线。本项目开展了点聚焦喇叭天线的设计研究工作，结合电磁仿真软件设计出了双折射面透镜喇叭天线，探讨了喇叭长度、喇叭张角和透镜曲率等结构参数对天线聚焦性能的影响，总结了聚焦透镜喇叭天线的设计方法，确定了通过S参数计算材料介电参数的方案，搭建了W波段材料介电性能测试系统，解决了毫米波介质材料介电性能测试难题。本项目开展了BaAl2Si2O8体系微波介质陶瓷的低温烧结性能探索，研究了LiF对(1-x)BaAl2Si2O8-xBa5Si8O21体系陶瓷烧结特性、相组成和微波介电性能的影响。在750℃下烧结，获得了具有优良微波介电性能(εr=7.63、Q×f=12410GHz、τf=-1.2ppm/℃)的瓷体。本项目还研究了BaAl2-2x(ZnSi)xSi2O8体系微波介质陶瓷材料的烧结特性和微波介电性能,研究发现(Zn0.5Si0.5)3+离子可以有效提高BaAl2Si2O8体系材料的相稳定度，提高LTCC瓷体的致密度，制备出了一种新型的BaZnSi3O8微波介质陶瓷(εr=6.60、Q×f=52401GHz、τf=-24.5ppm/℃)。本项目以Sr2+离子代替Ba2+离子，研究了Ba1-xSrxZnSi3O8体系微波介质陶瓷材料的烧结特性、相组成、显微结构和微波介电性能，获得了具有良好微波介电性能的SrZnSi3O8陶瓷(εr=6.12、Q×f=78064GHz和τf=-33.2ppm/℃)。本项目开发的BaAl2Si2O8体系材料有望实现进口低介电常数LTCC材料的国产化替代。