为了减小常规L波段高功率微波测量接收天线的结构尺寸及增益，设计了一种基于轴向缝隙馈电的小型化同轴扩张型天线。通过理论分析和数值模拟，选择了较优的结构尺寸，得到天线的增益及方向图特性：在1.3~1.6 GHz范围内，增益从-2.0 dBi变化至0.8 dBi；天线最大辐射方向在物理结构轴向。基于矢量网络分析仪E8362B的天线特性测量结果与数值计算结果基本一致：工作频率从1.3~1.6 GHz变化时，增益从-2.3 dBi变化至1.2 dBi；E面方向图主瓣宽度大于60°，轴向轴比大于35 dB，结果表明设计的天线能够满足L波段高功率微波测量天线低增益小型化要求。

In order to reduce the structure size and the gain of the high power microwave measurement receiving antenna, an expanded coaxial line small size antenna at L-band is investigated and designed. The more superior structure size is chosen by theoretical analysis and numerical calculation. The character of the gain and the pattern shows that, with the frequency varying from 1.3 to 1.6 GHz, the gain increases from -2 to 1.2 dBi linearly. The width of the radiation beam is smooth and more than 60°.And the axial ratio is more than 35dB. The gain and the radiation pattern of the antenna are calibrated with the Agilent E8362B network analyzer, and the calibrated results agree with the simulation. The results shows that the design of antenna can satisfy the requirements of low gain and small size to the L-band high power microwave measurement.