枝节状多频段微带天线的谐振机制与设计方法研究 The Resonance Principle and Designing Method of Multi-Bands Microstrip Antenna with Branch Shape

本文首先设计了一个三枝节微带天线，并给出了该天线的S11参数的仿真结果与实测结果。而后，采用了参数扫描的方法来分析天线相应结构的尺寸大小对谐振频率的影响，然后通过分析各个谐振频率处的天线表面电流分布，从理论上阐明参数扫描结果。为了获得更大的带外衰减，本文在三枝节天线的基础上又设计了一个四枝节天线，然后仿真并测试了其S11参数。接下来，本文设计了一个尺寸减小的四枝节天线，并分析了增强相应频段带宽的原理。最后，本文总结了设计该类枝节状天线的一般方法。  In this paper, a kind of three-bands microstrip antenna composed of three branches was designed. Also, the S11 parameters of the antenna were simulated and measured. After that, the relationship between the dimension of antenna and the resonance frequency of antenna was analyzed by scanning the dimension parameters. At the same time, the results of dimension scanning were explained by analyzing the distribution of surface currents on the antenna. In order to gain larger attenuation in stopband than the antenna with three branches, an antenna composed of four branches was designed and its S11 parameters were simulated and measured. Then, an antenna occupying smaller dimension than the above antennas was proposed and the principle of widening its frequency bandwidth was stated. In the end, the general method of designing this kind of antenna was concluded.