新型超宽带圆极化印刷天线

New type ultra-wideband circularly polarized printed antenna

针对传统圆极化微带天线轴比带宽较窄的问题,提出了一种新型的超宽带圆极化印刷天线。该天线结构简单,仅由C型辐射贴片和改进后的地板组成。采用微带馈电模式,整个天线尺寸仅为25mm×25mm×1mm。通过优化C型贴片和在地板上增加三角形和小长方形微扰结构,可以有效增加天线的阻抗带宽和轴比带宽。给出了天线的设计流程,从表面电流分布分析了圆极化天线的工作机理。加工了天线实物,并对其进行了测量。仿真和实测结果表明天线具有超宽的阻抗带宽和轴比带宽。天线的工作频带为4.4～11.6GHz(相对带宽为90%),3dB轴比带宽为3.6～11.3GHz(相对带宽为103.4%)。测量了天线的辐射性能和增益特性,实测结果与仿真结果吻合较好,证明了该天线的有效性。该天线可以应用于超宽带无线通信系统和卫星通信系统中。

Aiming at the problem that the bandwidth of traditional circularly polarized microstrip antenna is narrow,a new type of ultra-wideband circularly polarized printed antenna is proposed.The antenna structure is simple and only consists of C-shaped radiation patch and an improved ground plane.With microstrip feed mode,the size of the entire antenna is only25mm×25mm×1mm.By optimizing the C-shaped patch and adding triangle and small rectangular perturbation structures on the ground plane,the impedance bandwidth and axial ratio bandwidth of the antenna can be effectively increased.The design process of the antenna is given,and the working mechanism of the circularly polarized antenna is analyzed from the surface current distribution.Besides,the antenna is fabricated and measured.Simulation and measurement results show that the antenna has ultra wide impedance bandwidth and axial ratio bandwidth.The working frequency band of the antenna is4.4-11.6GHz(the relative bandwidth of90%),and the3dB axis ratio bandwidth is3.6-11.3GHz(the relative bandwidth of103.4%).The radiation performance and gain characteristics of the antenna are measured and the measured results are in good agreement with the simulated results,which proves the effectiveness of the antenna.The antenna can be applied to ultra-wideband wireless communication systems and satellite communication systems.