A novel numerical approach for the analysis of the near field of a moving body for the mobile communication systems

随着移动通信系统的迅速发展，对移动物体近场影响的评估变得非常重要。通过身体的运动来评估场的分布也是非常重要的。近年来，随着无线局域网的普及，有必要了解天线与运动体之间的相互作用。运动体的存在改变了辐射模式和特性。为了阐明无线局域网的传播特性，分析了天线和运动体对无线局域网传播特性的影响。为了在数值上解决这些问题，作者提出了一种新的坐标线与任意形状的移动边界重合的网格生成数值方法。利用所提出的变换技术，可以很容易地求解固定直角坐标系下的偏微分方程。最后，我们可以解决在固定直角坐标系下的移动问题。将一些数值结果与实验结果进行了比较，两者吻合良好。并将该方法应用于具有运动部件的微机电系统可变器件的分析。利用这种新技术，分析了由两个移动板组成的可变电容器。给出了速度与电容之间的数值结果，并准确地模拟了瞬态效应。这些研究结果分别发表在2000年的《电磁波与电子系统》（EW&ES）、2002年的《电信与无线电工程》（Telecommunications and Radio Engineering）和2003年的《IEEJ Trans》上。并在ACES2001、ACES2002、ACES2003、APMC2002、PIER2001、PIERS20002、APS/URSI2002、FESS-MMNA02等会议上发表。

As there has been rapid increase in a mobile communication systems, it becomes important to evaluate the effect of the near field of the moving body. It is also very important to evaluate the field distribution by the movement of the body. Recently, as the wireless LAN becomes popular, it is necessary to know the interaction between the antenna and the moving body. The radiation pattern and the characteristics are altered by the presence of the moving body. To clarify the propagation characteristics in the wireless LAN, the author examined the influence the antenna and the moving body analytically. To solve these problems numerically, the author has proposed a novel numerical procedure of grid generation having coordinate line coincident with an arbitrarily shaped moving boundary. By using the presented transformation technique, partial differential equations can be solved very easily in the fixed rectangular coordinate system. Finally, we can solve the moving problem in a fixed rectangular coordinate system. Some numerical results are compared with the experimental ones and excellent agreement between them are obtained. And also this technique was applied for the analysis of MEMS-based variable devices with moving parts. Using this new technique, a variable capacitor that consists of two moving plates is analyzed. The numerical results between the velocity and the capacitance are shown and the transient effect is accurately modeled. Those results were published in Electromagnetic Waves and Electronic Systems (EW&ES) in 2000, Telecommunications and Radio Engineering in 2002, IEEJ Trans, in 2003. And they were also presented in ACES2001, ACES2002, ACES2003, APMC2002, PIER2001, PIERS20002, APS/URSI2002, FESS-MMNA02.