分布式阻抗末端加载的TEM喇叭天线设计

基于功率容量和口径匹配扩展低频工作带宽两方面的考虑，设计了一种具有分布式阻抗末端加载结构的超宽带TEM喇叭天线。首先，对渐变式同轴-平板的巴伦结构进行了优化设计，扩展了馈电结构的工作带宽，提高了馈电效率；其次，对指数型TEM喇叭天线末端进行了分布式阻抗的匹配设计，其端口特性和辐射特性均得到了明显改善，并采用功率方向图和能量方向图对天线的辐射效果进行评估。实验结果表明，相对于指数型TEM喇叭天线，加载分布式阻抗匹配末端结构后，天线低频带宽展宽了330 MHz，天线主轴辐射电场峰峰值提高了10%，馈电效率提高了17%。

Design of TEM horn antenna based on distributed impedance end-loading

Based on the consideration of power capacity and aperture matching to extend the low-frequency operating bandwidth, an ultra-wideband TEM horn antenna with a distributed impedance end-loading structure was designed. First, the gradual coaxial-flat balun structure was optimized, which expands the working bandwidth of the feed structure and improves the feed efficiency. Secondly, the distributed impedance matching design was performed on the exponential TEM horn antenna, and its port characteristics and radiation characteristics were significantly improved. The power pattern and energy pattern were used to evaluate the radiation effect of the antenna. The experimental results show that, compared with the exponential TEM horn antenna, after the distributed impedance matching structure is loaded, the antenna low-frequency bandwidth is widened by 330 MHz, the peak-to-peak value of the antenna main axis radiated electric field is increased by 10%, and the feed efficiency is increased by 17%.