基于超表面的宽带圆极化方环缝隙天线设计

Design of a Square-ring Slot Antenna for Broadband Circular Polarization Based on Metasurface

为了扩展环形缝隙天线的轴比带宽,设计了一种基于超表面的宽带圆极化方形环缝隙天线。天线由5×5阵列方形贴片超表面、蚀刻方形环缝隙的金属接地板和馈电微带线构成。通过在方环缝隙内恰当位置加载短路片使其产生左旋圆极化辐射,对影响天线阻抗带宽和轴比性能的结构参数进行了优化分析。结果表明,天线的-10 dB阻抗带宽和3 dB轴比带宽分别达到了47.9%(4.82~7.86 GHz)和21.5%(5.65~7.01 GHz)。在圆极化工作频带内,辐射增益高于5 d Bi,最大增益达到了7.26 dBi。天线具备低剖面、宽带圆极化和高增益等特性,可用于无线通信系统中。

In order to improve axial ratio bandwidth of ring-slot antenna,a square-ring slot antenna was designed for broadband circular polarization based on metasurface. The antenna was composed of a 5 × 5 array square patch metasurface and a microstrip-line-fed shorted square-ring slot antenna. The left-handed circularly polarized( LHCP)radiation was generated by locating the shorted strip at appropriate position in the square-ring slot. The structural parameters that affect the impedance bandwidth and axial ratio of the antenna were optimized. Results show that the-10 dB impedance bandwidthand the 3 dB axial ratio bandwidth reach 47. 9%( 4. 82 ~ 7. 86 GHz) and 21. 5%( 5. 65 ~7. 01 GHz),respectively. The radiation gain is higher than 5 d Bi within the circular polarization operating band,and the maximum gain reaches 7. 26 dBi. With the advantages of low profile,broad circularly polarized radiation bandwidth and high gain,the antenna can be used in wireless communication systems.