一种基于笛卡尔圆定理的圆分形超宽带天线

A circular fractal UWB antenna based on Descartes circle theorem

提出了一种以微带线馈电方式的圆分形超宽带单极天线。天线依据笛卡尔圆定理,由圆分形结构辐射贴片与矩形接地面构成,在介电常数为4.4,厚度为1.6 mm的玻璃纤维基板（FR4）上进行设计。天线量测结果显示在返回损耗小于-10 d B时,天线的频带宽度范围为3.02~11.3 GHz,阻抗带宽为115.6%。在工作频带内实测4.5 GHz与10.0 GHz辐射方向图,在x-z平面具有良好的全向辐射特性,在y-z平面则呈现方向性。在3.1~10.6 GHz频带内量测出的增益值振幅范围落在4.31~6.13 d Bi。可以广泛应用于商业超宽带无线通信系统与医学影像领域中。

A circular fractal ultra wideband（UWB）monopole antenna with microstrip-feed is proposed. The antenna constructed based on Descartes circle theorem is composed of circular fractal SMT and rectangular ground plane,and designed on a fiberglass substrate（FR4）whose dielectric constant is 4.4 and thickness is 1.6 mm. The measured result of the antenna shows that,when the return loss is less than-10 d B,the frequency bandwidth of the antenna is 3.02~11.3 GHz,and the impedance bandwidth is 115.6%. The radiation patterns are measured at 4.5 GHz and 10.0 GHz in working frequency band,it shows that the antenna has good omnidirectional radiation characteristic in x-z plane and directional characteristic in y-z plane. The gain′s amplitude range measured at 3.1~10.6 GHz is 4.31~6.13 d Bi. This type circular fractal antenna can be widely used in commercial UWB wireless communication system and medical image filed.