中文摘要：

采用理论分析和粒子模拟相结合的方法，对连续电子注通过平板矩形光栅产生毫米波段史密斯一帕塞尔（SP）超辐射机理进行了研究，研究结果表明：选择恰当的电子注与光栅尺寸参数，光栅表面慢波将与电子注互作用，使电子注产生群聚，群聚的电子束团将在光栅表面产生史密斯－帕塞尔超辐射，其辐射频率为电子注与光栅表面慢波互作用同步点频率的整数倍，其辐射角度方向与史密斯－帕塞尔公式所预期的基本一致，表面慢波由于光栅的有限长度也能在其端头以一定的形式辐射出去。

英文摘要：

In combinating the theoretical analyses with Particle-in-Cell （PIC） simulations, the physical mechanisms of millimeter band superradiant Smith-Purcell（SP） radiation of continued electron beam passing the planar rectangular grating was studied. The results show that the interactions of surface slow wave with the electron beam occur with the suitable pa- rameters of electron beam and grating, which results in the bunching of electron beam. The super radiation of SP will be produced on the surface of gating due to the bunched electron beam. The radiation frequency is the integral times of synchronous point＇s frequency of surface wave and electron beam interaction. The radiation angle is in agreement with the SP theory and the slow wave can be radiated at the both ends of grating as the finite lengths.