Research on Desighn Method of Antennas Used for Compact Portable Telephine

为了建立便携式电话用天线的设计方法，本文采用本文作者提出的一种新的方法——伽辽金矩法和时域有限差分法，对安装在便携式电话导体体上的天线的特性进行了分析。本研究开发的s型天线采用时域有限差分法进行了设计和制作。将导盒内部格林函数与矩量法相结合的新方法应用于对安装在导盒上的天线的分析。结果表明，该方法的分析精度与传统的伽辽金矩法基本相同，而所需的CPU时间约为矩法的1%。对安装在导电盒上的槽形天线和单极子天线的特性进行了数值计算。进一步证实了该方法在移动电话天线的数值设计方法中是可行的。应用该方法对有限长导电圆柱上的槽形天线特性进行了分析。利用时域有限差分法分析了单极天线、平面倒f形天线和s形天线等典型便携式电话天线的特性，证实了时域有限差分法在便携式电话设计方法中的有效性。分析和讨论了电话机机身周围介质层的作用和对人体的影响。采用时域有限差分法对s型天线进行了数值设计和制作。实验表明，s型天线即使在手机体积小于100cm^2的情况下也具有较宽的频带宽度，并且在人体存在的情况下，其辐射效率的下降很小。少

In order to establish design methods of antennas used for the portable telephones, analyzes of the characteristics of antennas mounted on a conducting body of the portable telephone have been performed using a new method proposed by the present investigators, the Galerkin moment method and the finite diffierence time domain (FDTD) method. S-shaped antenna, which was developed by the present investigators, has been designed by the FDTD method and fabricated.1. The new method, combining the interior Green's function of the conducting box and the moment method has been applied to the analysis of the antennas mounted on the conducting box. The results show that the accuracy of the analysis is almost the same to that of the conventional Galerkin moment method, while the required CPU time is about 1% of that in the moment method. Numerical results of the characteristics of a slot antenna and a monopole antenna mounted on the conducting box have been obtained . Thus, it has been confirmed tha … More t the new method is available for the numerical design method of the portable telephone antennas. The present method has been applied to analyze the characteristics of a slot antenna on a conducting circular cylinder with finite length.2. The characteristics of typical antennas used for the portable telephone such as the monopole antenna, the planar inverted F-shaped antenna and the S-shaped antenna have been and analyzed by using the FDTD method, the validity of the FDTD method for the design method of the portable telephone has been confirmed. The effect of a dielectric layr surrounding the body of telephone and the influence of the human body have been also analyzed and discussed.3. S-shaped antenna has been numerically designed by the FDTD method and fabricated. It has been shown experimentally that the S-shaped antenna has a wide frequency band width even when the volume of the portable telephone is less than 100cm^2 and the decrease of the radiation efficiency in the presence of the human body is small. Less