扁波导馈电的平板缝隙天线阵的带宽扩展

扁波导馈电的平板缝隙天线阵,除了馈电波导内部耦合增强以外,带宽也受到限制.文章从谱域角度分析了缝隙天线的内外场分布,在此基础上,得到了周期波导和金属波导中各模式场的功率/储能谱.计算了波导缝隙天线的Q值并分析其变化规律,解释了扁波导馈电带宽受限的原因是辐射波导内的驻波储能场增强造成的.提出了在缝隙两侧增加扼流槽的改进方案,并同样从谱域的角度分析了该方案对带宽改善的影响.将该方案应用于一个实际的SIW平板波导缝隙天线阵设计中,获得了8.1%的带宽.

On the Bandwidth of Planar Slot Antenna Array Fed by Low Waveguide

When planar slot antenna array is fed by low waveguide, the internal mutual coupling is strong and the bandwidth is limited. In this paper, the field of slot array is analyzed in spectrum domain, and the spectrums of radiation power and storage energy are calculated. The quality factor Q is analyzed. For the planar slot antenna array is fed by low waveguide, the reason of bandwidth limitation is caused by the increase of energy sorted in standing wave in the radiation waveguide. Adding chokes besides the radiation waveguide could extend the bandwidth, and this is proved in spectrum domain. This method is implemented in an SIW planar slot array, and the bandwidth is more than 8.1%.