X波段GW级长脉冲高功率微波源的设计与实验

通过理论分析指出,单模相对论返波振荡器内的平均场强正比于其工作频率,工作在高频段难以实现长脉冲运行。采用电磁场仿真方法,比较了X波段单模和过模慢波结构的场分布特点,结果表明:增加过模比能有效减小慢波结构表面的射频场强,但由于场分布变化导致场强的减小与过模比的增加相比并不显著。利用过模比约为3的慢波结构设计了一种X波段长脉冲高功率微波源。实验中,在单次运行条件下,输出微波功率达到2 GW、脉宽80 ns;在20 Hz重复频率运行条件下,输出微波功率达到1.2 GW、脉宽100 ns。器件产生的微波频率为9.38 GHz,主模为TM01,效率约24%。微波窗口和慢波结构表面的射频击穿是目前实验中限制微波功率和脉宽增加的关键因素。

Design and experiment of X-band long-pulse high power microwave source

The difficulties in producing long pulse high-power microwave (HPM) with relativistic backward wave oscillators (RBWOs) are analyzed theoretically. The field distributions of a single-mode slow-wave structure (SWS) and an overmoded SWS with the overmode ration of about 3 are calculated and compared, which indicates that the latter can effectively reduce the RF-field on SWS surface under the same energy storage, but the reduction is not as notable as the increase of the overmode ration due to the change of field distribution. An X-band long pulse HPM source using an SWS with the overmode ration of 3 is designed and investigated experimentally. The devices generates 2 GW microwave power with pulse duration of 80 ns at single shot mode, and 1.2 GW microwave power with pulse duration of 100 ns