一种新颖的星载四臂螺旋天线巴伦的设计

Design of a Novel Spaceborne Quadrifilar Helix Antenna Balun

根据卫星导航定位中的天线宽波束、圆极化、低仰角增益等要求,设计了一种新颖的适用于四臂螺旋天线的馈电巴伦。通过在天线外导体上开4条长度呈一定规律的缝隙来实现巴伦结构,且对天线的外导体、巴伦结构、电连接器进行一体化设计。天线的4根螺旋臂的两端分别连接在一体化外导体的馈电端和非馈电端,巴伦结构仅产生天线所需的90°相位差,4根螺旋臂仅产生天线所需的方向图,从而降低了四臂螺旋天线的设计和调试难度。测试结果表明,天线实现了较好的宽波束圆极化特性。

Satellite navigation systems require the antenna to provide wide beam,circular polarization and high gain at low elevation.Based on these needs,a new type of balun for quadrifilar helix antenna is designed.The structure of the balun is realized by cutting four splits with regular length on the outer conductor and adopting integrated design for the outer conductor,the balun structure and the electrical connector.The two ends of the four spiral arms are respectively connected to the feed end and the non-feed end of the outer conductor.The 90phase difference is only produced by the balun structure and the antenna pattern is only produced by the four spiral arms.Therefore,the diffculty of design and debugging of the antenna are reduced.The experimental results show that the antenna can provide good characteristics of wide beam and circular polarization.