为深入研究高功率微波(HPM)作用下介质窗沿面击穿破坏的物理机制，探索提高闪络场强阈值的方法和途径，开展了介质窗表面矩形刻槽抑制电子倍增的理论与试验研究。首先根据动力学方程建立了介质窗表面电子倍增模型并分析了介质窗槽内电子运动轨迹，考虑了矩形槽结构对表面微波电场的影响，理论分析表明在闪络击穿的起始和发展阶段矩形槽可有效抑制电子倍增。在S波段(2.86 GHz，脉宽1 μs)下开展了介质窗表面矩形刻槽的击穿破坏试验，试验结果发现表面矩形刻槽可大幅度提高微波传输功率，在槽深(1.0 mm)一定时不同的刻槽宽度(0.5 mm和1.0 mm)对应的微波功率抑制范围不同。采用PIC-MC仿真模拟槽内倍增电子的时空演化，仿真结果很好地验证了试验现象。

Dielectric window is an important component of high power microwave (HPM) generation device. However, breakdown easily occurs on vacuum/dielectric interface with the development of HPM device. Surface breakdown limits the generation and transmission of HPM, and becomes the bottle neck of HPM technology development. For further understanding the breakdown mechanism and improving the threshold, the theoretical and experimental investigation of multipactor suppressed in rectangular grooves simulation model is built in this paper. From the dynamic analysis and PIC simulation, the movement of multipactor electron in grooves is obtained and the physical process of rectangular grooves suppression breakdown is simulated. Breakdown experiments of polytetrafluoroethylene (PTFE) under an S-band (2.86 GHz) HPM are conducted, and the obtained results correspond to the suppression theory.