Calculation And Simulation Of The Electro-magnetic Fields Distribution Of The Mobile Communication Station Antenna

Finite-difference Time-domain (FDTD) method is a considerable effective and remarkable important method to solve electromagnetic (EM) numerical computation problems. It is applied widely to design and analysis of antenna, EM scattering, EM compatibility (EMC), radar technology, radio wave propagation, communication technique of optical fib and mobile, microwave, bioelectromagnetics, etc.In this thesis, it introduces briefly the basic theory of simple linear antennae radiation mechanism and discusses the spatial EM distribution of the antennae. Then it presents three-dimension,two-dimension and one-dimension differential equations of FDTD method and discusses the problems of numerical dispersion and stability. It emphasizes on converting the equations to the forms which computer can recognize and calculate directly by a computer program and simulating entire EM radiation process of a half-wave-linear antenna with unrestricted boundary using MATLAB software program. Because of antennae in an open space with no boundary, we can regard the infinite region as a finite region with a perfect matched layer around it. Therefore we can easily understand and analyze some important characteristics of some simple linear antennae by using FDTD method. Of course, we also can study the radiating trains of several complicated linear antennae arrays by the same means, especially the direction polar diagram. At the end of this thesis, it combines the research on EM field distribution near a antenna of a base transceiver system (BTS) with a practical mobile communication engineering.The purpose of this research is to make people realize that electromagnetic pollution has become a latent killer which not only damages our healthy severely, but also perhaps will interfere the precision and life of the exact electro facility, while we sharing its convenience and advantage.