一种应用于ITS的三频微带天线的设计

Design of a Tri-Band Circularly Polarized Microstrip Antenna for ITS Application

设计了一种应用于智能交通系统(ITS)的三频微带天线,分别工作在GPS(1.575GHz)、WLAN(2.45GHz)以及DSRC(5.8GHz)。采用堆叠结构实现大的双频比,其中顶层贴片工作在DSRC,底层贴片通过边缘处加载四个相等矩形槽来实现双频。通过在方形贴片的一个对边边缘处加载两个相等的矩形槽来实现圆极化。通过调整对角线上馈电点位置、平移顶层贴片以及改变底层贴片上的过孔大小来实现频带内的阻抗匹配。仿真和测试结果表明吻合良好,该天线在三个频段内有着良好的阻抗匹配、轴比以及辐射方向图,能够满足设计要求。

In this paper,a tri-band microstrip antenna applied in intelligent transport system( ITS) is designed,which operates at GPS( 1. 575GHz),WLAN( 2. 45GHz) and DSRC( 5. 8GHz). The wide frequency ratio is achieved by using the stacked structure,the top patch can perform DSRC,and the edges of the bottom patch with four equal slots can realize dual-band. By cutting a pair of narrow slots at the edge of the square patch,the antenna can perform circularly polarized radiation. The impedance matching in three bands is achieved by adjusting the feed position,shifting the top patch,and changing the size of via hole in bottom patch. The results show good agreement between simulation and measurement,and the antenna has good performance on impedance matching,axial ratio and radiation pattern,which can meet the requirement.