基于半圆分形的柔性超宽带天线

Flexible UWB antenna based on semicircular fractal

以柔性材料聚酰亚胺(PI)作为介质基板材料,设计了一种柔性超宽带(UWB)半圆分形天线。天线辐射单元采用四阶半圆迭代嵌套分形结构,通过不同分形半圆调节电长度,增加天线的工作谐振点。通过在接地板开槽提高天线的阻抗匹配特性,实现UWB辐射。利用共面波导馈电方式提高天线的集成性。仿真与测试结果表明:所设计天线的阻抗带宽为2.98-10.61 GHz,带内全向增益达到5.58 dBi,天线最终尺寸为30 mm×24 mm,实现了小型化和可弯曲的特性,在共形于13 mm半径的圆柱后,天线仍能保持UWB辐射性能。

A flexible ultra-wideband(UWB)semicircular fractal antenna is designed using polyimide(PI)as dielectric substrate material.The antenna radiating element adopts a fourth-order semicircular iterative nested fractal structure,which adjusts the electrical length through different fractal semicircles to increase working resonant points of the antenna.By slotting the ground plane,impedance matching characteristics of the antenna are improved,achieving UWB radiation.The integration of antenna is enhanced using coplanar waveguide feeding method.Simulation and test results show that impedance bandwidth of the antenna is 2.98-10.61 GHz,with an in-band omnidirectional gain achieve 5.58 dBi.The final size of the antenna is 30 mm×24 mm,achieving miniaturization and flexibility.Even when conformed to a cylinder with radius of 13mm,the antenna still maintains its UWB radiation performance.