超宽带TEM喇叭天线优化设计与实验

Optimization and experiment of UWB TEM horn antenna

针对用于成像雷达系统的超宽带TEM喇叭天线进行了优化设计,兼顾辐射性能、馈入反射和小尺寸条件,采用平滑渐变结构和加载技术代替原设计,增加了低频电流的回流通道,从而改善了天线的低频特性,增强了其定向辐射能力。在理论分析的基础上对其进行了仿真,并按照仿真结果实际制作了一副天线,对天线进行了测试。仿真与实测结果表明:在电压驻波系数小于2时,该天线具有11∶1的阻抗带宽,较强的辐射能力和良好的定性辐射特性,能够满足雷达系统的需求。

The ultra-wideband TEM horn antenna fed by coaxial cable and loaded with lumped resistor for the application of imaging radar system is presented.The low-frequency characteristic of the antenna and its directional radiation ability are largely improved with the smoothly tapered structure and loading technology instead of the original design taking account of the radiation characteristics,the reflection from the feed section and the dimension limitations.Finally,a pair of antennas are fabricated and measured based on the theoretical analysis and simulation.It is concluded that the antenna has a good impedance bandwidth of about 11 ∶ 1,good radiation characteristics and moderate gain for voltage standing wave ratio （VSWR） below 2 by comparing the simulated results with the measurements,which may be suitable for the requirements of the radar system.