应用于毫米波车地通信的小型化间隙波导缝隙阵列天线设计

Design of miniaturized gap waveguide slot array antenna for millimeter wave vehicle-to-ground communication

在高速磁悬浮列车毫米波车地通信系统中,要求车载天线具有小型化、宽频带、圆极化和辐射扇形波束等特点。为了更好地满足这些要求,提出了一种中心馈电的小型化间隙波导缝隙阵列天线,采用环形缝隙单元辐射右旋圆极化波,通过脊间隙波导一分三十二路功分网络实现等幅同相馈电。采用全波电磁仿真软件设计了一款中心频率为38 GHz的2×16单元间隙波导缝隙阵列天线,并进行了实验测试。测试结果表明:在37~39 GHz频带范围内,天线驻波比小于1.42,增益大于21 dBi,轴比小于3 dB,俯仰面波瓣宽度为4.1°~4.3°,方位面波瓣宽度为34.7°~36.5°,满足毫米波车地通信系统车载天线的设计需求。

In the high-speed maglev train millimeter-wave vehicle-to-ground communication system,the required characteristics of vehicle antenna should be miniaturized,broadband,circular polarized,and sector beam.To meet the requirements,a center-fed miniaturized gap waveguide slot array antenna was proposed.The annular slot unit was used to radiate right-handed circularly polarized waves.And the same feed amplitude and phase was realized by a ridge gap waveguide with one-32-way power divider.A gap waveguide slot array antenna of 32-unit with the central frequency of 38 GHz was designed by using full-wave electromagnetic simulation software.The antenna was fabricated and measured.The measured results show that from 37 GHz to 39 GHz the voltage standing wave ratio of the antenna is less than 1.42,the gain is greater than 21 dBi,the axial ratio is less than 3 dB,the half power beam width in elevation plane is 4.1°-4.3°,and the half power beam width in azimuth plane is 34.7°-36.5°.The designed antenna could meet the designed requirements of the millimeter wave vehicle-to-ground communication system.