毕业设计(论文)

矩量法分析振子天线粗细对天线的影响

摘 要

在现代通讯系统中，天线是其不可或缺的组成部分。随着科学技术的发展，人们对天线的要求也越来越高。天线技术也变的越来越重要。线状天线是现在天线中应用极为广泛的天线。而振子天线是线状天线中比较简单而又典型的。矩量法是一种用来分析天线和电磁场的经典数值计算方法。它以计算精度高、计算速度快、适用性强的特点获得了广泛的研究和应用。学习矩量法，并用振子模型分析了振子天线，分别对长度为500mm ，半径各为1mm，5mm，10mm，50mm的对称振子进行计算，并通过计算结果的比较得到了振子天线粗细对天线性能的影响，即：在相同的激励条件下和一定限度内，随着振子半径的增大，输入阻抗的感性逐渐减弱、容性逐渐增强；阻抗的频率响应越平坦，天线的带宽越宽；谐振频率逐渐减小，天线的有效长度逐渐增大；辐射功率逐渐增大。将上述结果与所学理论比较后，可知结果与理论相符合。在实际中可以根据对天线性能的要求，选择合适粗细的对称振子天线。

关键词　矩量法；振子天线；对称振子；电流分布方程

Abstract

In a modern communications system, antenna is an very important integral part of it. Along with the development of science and technology, people are increaseingly high requirements for the antenna. Antenna technology has become increasingly important. Linear antenna is very extensive application of the antenna in modern antenna. The moment method is used to analyze a antennas and electromagnetic classical numerical calculation method . It is accurate, fast calculation, the characteristics of applicability is a broad research and application. Learning Moment Method, Using dipole model analysis of the dipole .And the symmetry dipole is computed when its length is 500 mm and its radius is respectively 1 mm,5 mm, 10 mm, 50 mm. .The computation results show how the thickness of dipole antenna influences the capability of antenna , namely : in the same incentives and certain limits, with the dipole radius, inductance of the input impedance gradually weakened, capacitive gradually increased. Impedance of the more flat frequency response, the antenna more wide bandwidth; resonant frequency gradually decreases, the effective antenna length gradually increasing; radiation power is gradually increasing. These results will be compared with the theory comparison, we can see the results that is accord with the theoretical. And different thickness symmetry dipole antenna can be chosen by different requirement on capability of antenna in practice.

Keywords　 moment method ; dipole antenna ;symmetry dipole