宽带弯折渐变印刷四臂螺旋天线的设计

Design of Broadband Folded Tapered Printed Quadrifilar Helical Antenna

目前,印刷四臂螺旋天线可以广泛的应用于诸如移动卫星通讯,广播卫星系统和全球定位系统等多种系统中。然而,对于这些系统应用而言,传统的印刷四臂螺旋天线的带宽已不能满足它们的需求。因此,本文设计一种新型的印刷四臂螺旋天线。展示了一种渐变辐射臂宽度和寄生短路臂相结合的宽带技术。同时本文提出了一种基于平行双线的功分馈电网络,有效的减小了传统四臂螺旋天线馈电网络的尺寸。实测结果表明该天线的工作带宽达到了28%(1.86~2.5GHz)以上。

Today the printed quadrifilar helical antenna（PQHA）can be widely applied to many applications such as mobile satellite communications,broadcasting satellite systems and global positioning systems. Nevertheless,the bandwidth of a conventional PQHA could be insufficient for applications. A new PQHA design is investigated in this paper. A technique of Increasing the bandwidth of the PQHA by modifying the wire width and adding a shorted parasitic helix is presented. And a power divider based on double-sided parallel striplines（DSPSL）is proposed to reduce the size of the conventional feeding network. Experimental results show that the bandwidth can reach more than 28%（1.86-2.5 GHz）.