设计了一种无外加引导磁场S波段相对论返波振荡器,采用阳极网提取电子,并设计了非均匀慢波结构。通过Karat 2.5维全电磁粒子模拟程序研究了器件内束-波作用的物理过程。典型模拟结果为:当二极管工作电压330 kV、电流2.83 kA时,器件在频率2.79 GHz处获得较高的微波输出,经27 ns后饱和,输出微波的功率达158 MW,效率约为16.8%。

An S-band relativistic backward wave oscillator without external guiding magnetic field has been investigated using the Karat 2.5D particle-in-cell simulation code. An anode foil is used to extract the electron beam and the non-uniform slow-wave-structure is designed for increasing the microwave output power of the device. Detailed beam-wave interaction pictures in the oscillator were presented. The simulation results show that a 2.79 GHz,158 MW high power microwave can be obtained when the beam energy is 330 kV and the beam current is about 2.83 kA. The oscillator starts to oscillate at 15 ns,and the nonlinear saturation of the device occurs at about 25 ns. The efficiency is about 16.8% after saturation.