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

在本研究中，开发可在日本使用的天线系统的目的是为了开发使用地球静止卫星的移动的卫星通信的基本技术。本研究的内容可以分为以下三点：1.研制了收发两用的圆极化双频三角形贴片阵列天线;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了卫星通信的室外实验，为了减小圆阵天线的尺寸，研制了一种圆极化三角形贴片天线。由此，能够实现天线的小型化，并且能够提高低仰角方向的增益。所开发的天线单元可以很容易地制成圆形阵列结构，并且沿着小型化，这种结构允许在一个特定的频率范围内， 关于我们 通过双馈电可以获得圆极化辐射，当采用阵列结构时，由于接收和发射元件都组合在单层中，因此实现了双频工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，并以与天线集成为目标，设计了一种基于ON-OFF方法的小型化卫星跟踪控制电路，该电路不使用任何移相器。由于整个电路可以用芯片元件实现，所以基本上集成的单元以及低成本成为可能。此外，开发了利用光纤陀螺仪和个人计算机的自动跟踪系统，并加载了能够根据车辆方向控制辐射光束的功能。在电波暗室中检查天线系统以确认其性能的有效性。此外，为了确认所开发的天线在真实的环境条件下的性能，将伪卫星站设置在千叶大学内的建筑物的屋顶上，研究了天线（1）实际装载在实验车辆上时的特性。仿真结果表明，该天线具有小型化、双频工作、天线电跟踪等优点，并对系统的整体性能进行了分析。最后，通过仿真和测试，验证了该天线的有效性。这些结果在IEICE的技术报告、IEEEAP-S和图像信息和电视工程师协会的会议录中被总结和报道。此外，研究结果还发表在IEICE Transactions on Communications（日文版）和IEEE Transactions on Analog & Propagation上。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