Realization of an Antenna system for the Next Generation of Mobile Satellite Communications Station

在这项研究中，开发一种可以在日本使用的天线系统的目的是为了开发利用地球同步卫星进行移动卫星通信的基本技术。研究内容可分为以下三点：1.收发两用圆极化双频三角形贴片天线的研制；2.卫星跟踪开关电路及控制系统的研制；3.利用实验车和伪卫星站进行卫星通信的室外实验。为了更精确地降低圆阵天线的尺寸，研制了一种圆极化三角形贴片天线。由此，天线可以小型化，并且可以提高低仰角方向的增益。开发的天线单元可以很容易地制成圆形阵列配置，以及它的小型化，一种允许st…的配置在阵列结构中，由于接收和发射元件被组合在一层中，因此实现了双频段操作和良好的隔离特性。为了改善天线的辐射特性，对基片的相对介电常数、单元形状和单元间距进行了优化，设计了一种基于开关方法的不使用移相器的小型化卫星跟踪控制电路。由于整个电路可以用芯片元件实现，因此可以实现基本集成的单元以及低成本。此外，利用光纤陀螺和个人计算机开发了自动跟踪系统，并加载了能够根据车辆的方向控制辐射光束的功能。此外，为了验证天线在真实环境条件下的性能，在千叶大学内的一栋建筑的屋顶上设置了一个伪卫星站，调查了天线(1)实际登上实验车时的特性。在本研究中，通过数值模拟和测量证实，本研究所开发的天线是小型化、双频工作、从天线上配备电跟踪的天线，并对系统整体性能进行了分析。最后，这些结果在IEICE的技术报告、IEEE AP-S和图像信息与电视工程师学会会刊中进行了总结和报告。此外，研究结果还发表在IEICE通信会刊(日文版)和IEEE天线与传播会刊上。较少

In this research, the development of an antenna system that can be used in Japan has been aimed in order to develop a basic technology for mobile satellite communications using a geostationary satellite. The contents of the research can be divided into the following three points :1. Development of circularly polarized dual-band triangular-patch array antenna for both reception and transmission ;2. Development of switching circuit and control system for satellite-tracking ;3. Outdoor experiments of satellite communications using an experimental vehicle and a pseudo-satellite station.To be more precise, in order to reduce the antenna dimensions in circular array configuration, a circularly polarized triangular patch antenna has been developed. Herewith, the antenna can be miniaturized and the gain at low elevation direction can be improved. The developed antenna element can easily be made in circular array configuration and along with its miniaturization, a configuration that allows a st … More able circularly polarized radiation by means of a dual feeding can be obtained.When put into an array configuration, as both reception and transmission elements are combined in a single layer, a dual-band operation and good isolation characteristics are realized. In order to improve the radiation characteristics, the relative permittivity of the substrate, the element shape, and the distance between the elements are optimized.A miniaturized control circuit based on ON-OFF method for satellite tracking and that does not make use of any phase shifter is developed aimed at an integration with the antenna. As the whole circuit can be implemented with chips components, a substantially integrated unit as well as low cost becomes possible.Moreover, an automatic tracking system making use of a fiber optic gyro and personal computer is developed and a function enabling the control of the radiated beam depending on the direction of the vehicle is loaded. The antenna system is examined in the anechoic chamber to confirm the effectiveness of its performances.In addition, to confirm the performances of the developed antenna under a real environmental conditions, a pseudo-satellite station is set on the roof of a building inside Chiba University, the characteristics of the antenna (1) when actually embarked in the experiment vehicle are investigated. The values of a budget link, for which the transmitted power and the operating frequency of the pseudo-satellite station are similar to the ones used for ETS-VIII, has been used.In this research, it is confirmed by both numerical simulations and measurements that the antenna developed in this research is miniaturized, dual-band frequency operating, electrically tracking equipped from the antenna and overall system performances analysis.Finally, these results are summarized and reported in the Technical Report of IEICE, the IEEE AP-S, and the Proceeding of the Institute of Image Information and Television Engineers. In addition, the results are also published in the IEICE Transactions on Communications (Japanese version) and the IEEE Transactions on Antennas & Propagation. Less