一种正六边形嵌套分形超宽带天线的设计

Design of An Ultra-Wideband Antenna with A Hexagonal Nested Fractal Structure

针对当前超宽带天线存在的方向性差、增益小的现状,提出了一种正六边形嵌套分形的超宽带天线。天线利用嵌套分形结构的自相似性和空间填充特性,有效拓展带宽,缩减天线尺寸。通过对天线维数进行仿真分析,选择带宽满足超宽带指标的四维和五维天线;对四维天线和五维天线的E-H面方向图及增益进行对比得知,五维天线较高增益由方向图畸变产生,故选择方向性更好的四维天线为此次设计的目标天线。目标天线尺寸仅为20 mm×23 mm×1.6 mm,带宽为2.7~10.6 GHz,增益为1.8~7.8 dBi,且天线实现了良好阻抗匹配。与引文其它天线相比,目标天线具有较小的尺寸,同时具有良好的方向性和较高的增益。天线实测结果与仿真基本吻合,验证了其研究与应用价值。

Aiming at the current situation that the ultra-wideband antenna has poor directivity and small gain,an UWB antenna with a hexagonal nested fractal structure is proposed.The antenna utilizes the self-similarity and spatial filling characteristics of the nested fractal structure to effectively expand the bandwidth and reduce the antenna size.By simulating and analyzing the antenna dimension,the 4 D and 5 D antennas whose bandwidth meets the UWB index are selected.Comparing the E-H plane pattern and gain of the 4 D and 5 D antenna,it shows that the 5 D antenna obtains a higher gain by generating distortion.Therefore,the 4 D antenna with better directivity is selected as the target antenna.The target antenna size is only 20 mm×23 mm×1.6 mm,the bandwidth is 2.7~10.6 GHz,the gain is 1.8~7.8 dBi,and a good impedance matching is achieved.Compared to other antennas of the citation,the target antenna has a smaller size with good directivity and higher gain.The measured results of the antenna are basically consistent with the simulation results,which verify its research and application value.