基于小型化HIS结构的宽波束微带圆极化天线设计

Design of wide beam microstrip circularly-polarized antenna based on miniaturized HIS structure

提出一种HIS(高阻抗表面)结构加载的小型化圆极化微带天线。天线采用方形微带贴片作为辐射单元,通过加载槽线的单元结构实现HIS阵列反射器的小型化设计,该HIS结构具有良好的角度稳定性与极化稳定性,能够展宽微带天线的3 dB轴比波束宽度并且实现天线方向图的高前后比。仿真结果显示,天线的-10 dB阻抗带宽为290 MHz(4.97%),3 dB轴比带宽为70 MHz(1.21%),在中心频率5.8 GHz处的E面3 dB轴比波束宽度为205.3°(-109.7°~95.6°),H面3 dB轴比波束宽度为200.4°(-101.6°~98.8°),具有宽轴比波束特性;天线辐射方向图具有高前后比特性,可以达到29.7 dB。

A miniaturized circularly polarized microstrip antenna loaded with HIS(high impedance surface)structure is designed.In the design of the antenna,the square microstrip patch is adopted as the radiation unit,and the miniature design of HIS array reflector is realized by loading the unit structure with the slot line.The HIS structure has good angle stability and polarization stability,and can expand 3 dB axial ratio beamwidth of microstrip antenna and realize the high front-to-back ratio of the antenna radiation pattern.The simulation results show that the antenna′s impedance bandwidth at-10 dB is 290 MHz(4.97%),the axial ratio bandwidth at 3 dB is 70 MHz(1.21%),the axial ratio beamwidth of plane E at 3 dB is 205.3°(-109.7°~95.6°)when the center frequency is at 5.8 GHz,and the axial ratio beamwidth of plane H at 3 dB is 200.4°(-101.6°~98.8°).It can be seen from the above that the designed antenna has the characteristic of wide axial ratio beamwidth.In addition,the radiation pattern of the antenna has high front-to-back ratio,which can reach 29.7 dB.