FDTD计算共面波导馈电双频天线

Study of Coplanar-Waveguide-Fed Dual-Band Antenna by FDTD

基于共面波导传输结构的诸多优越特性,如低剖面、重量轻和低成本等,共面波导结构成为一个研究的重点。首先,给出一个共面波导馈电的双频天线结构,并分析了其工作原理,得出了工作频率与几何尺寸的定性关系;接着,介绍了时域有限差分法对共面波导馈电双频天线进行仿真计算时的一些关键技术,如激励源的设置,完全匹配层的设置和近远场外推技术,特别是激励源的设置,引入了模式匹配的激励设置方法,与传统激励源的设置相比,减少了计算时间与内存的需要;最后,给出了天线特性的计算结果与实测结果,具有较好的一致性,满足了双频天线工作的基本要求;同时,电场分布证明了双频工作的机理,对此种天线设计参数选取有一定指导意义。

The research for coplanar- waveguide transmission line has become an important project recently due to its advantages such as low profile, light weight and low cost. Meanwhile, along with the requirement of developing the communication equipment into a mult -functional and miniaturized one, dual -band antenna also attracts more attention. In this paper, a CPW - fed dual - band antenna is proposed, and the working principle of it is analyzed, consequently, the relation between working frequency and geometry- sizes is obtained. And then, some key techniques and notes about FDTD are introduced, such as the setting of source, modified technique of near - field to far - field and setting of radiation boundary. Compared to traditional setting source, adopting mode match method can decrease the computation time. Finally, the computed results by FDTD and measured results are given, both of which have a good agreement at the working band. It has guidance meaning to design this kind of dual - band antenna, according to dual - band mechanism proved by electric field distribution. At the same time, the working mechanism of the dual - band is demonstrated by electric field distribution, which shows a guidance meaning to the parameter selection in the design of this kind of dual - band antenna.