一种可调式自相移印制四臂螺旋天线

船载海事卫星(INMARSAT)通信天线波束宽度较窄,且在风浪下船体摇晃难以与低仰角处卫星进行通信。提出一种带有开槽巴伦的可调式自相移四臂螺旋天线,避免了馈电网络造成的横向面积过大等问题。天线长振子臂长度可微调,结合调整开槽巴伦上的移动环,可以局部改变天线通信频带。通过基于有限元算法的HFSS仿真和实验,得出该天线具有宽波束特性,3 dB 波瓣宽度约为165°。另外,可以实现左右圆极化互相转换,在较宽的角度下,天线轴比低于6 dB。该天线既可以作为海事卫星通信天线,又可以作为北斗、GPS 导航天线和测浪高所用的左旋圆极化天线。

An Adjustable Self-Shift Printed Quadrifilar Helix Antenna

The beam width of INMARSAT communication antenna is narrow, and it is difficult to communicate with the satellite at low elevation when the ship sways in the wind and waves. In this paper, an adjustable self-shifting four-arm helical antenna with slotted balun is proposed, which avoids the problem of large transverse area caused by feeding network.The length of the long dipole arm of the antenna can be adjusted, and the antenna communication frequency band can be changed locally by adjusting the moving ring on the slotted balun. Through HFSS simulation and experiment based on finite element method, it is concluded that the antenna has wide beam characteristics, and the width of 3 dB lobe is about 165°. In addition, the circular polarization can be converted from left to right. At a wide angle, the antenna axis ratio is less than 6 dB. The antenna can be used not only as a maritime satellite communication antenna, but also as a left-handed circularly polarized antenna for Beidou, GPS navigation antenna and wave height measurement.