设计了一种工作在Ku波段的低磁场同轴相对论返波管。器件工作在同轴TM01近π模式, 采用两段式慢波结构构型, 在前后段慢波结构中分别主要进行电子束调制与能量提取, 以实现高效率工作。通过设计非对称反射腔, 引入电子束预调制, 进一步加深电子束调制深度, 提高了束波互作用效率。通过调节慢波结构中间漂移段长度, 进一步优化器件内部场分布, 提取段慢波结构处轴向电场强度得到显著增强, 器件工作效率可提升至35%。最终, 当磁场强度0.6 、二极管电压490 V、二极管电流7.5 A时, 获得1.27 GW微波输出, 效率约35%, 微波频率为14.7 GHz。

A Ku band coaxial relativistic backward wave oscillator (RBWO) with low magnetic field is presented in this paper. This RBWO works at coaxial TM01 π-mode which contains two-segment slow wave structures (SWSs). The first segment SWS mainly modulates the intense electron and the second one mainly extracts the microwave energy. By introducing pre-modulate using an asymmetry reflector, the modulation depth is improved. By optimizing the length of the drift between SWSs, the field distribution is optimized and the axial electric field intension of the extract SWS is farther improved. The efficiency of the RBWO is improved. Finally ,when the magnetic field is 0.6 T, the diode voltage is 490 kV, the diode current is 7.5 kA, a 1.27 GW microwave is obtained with an efficiency of 35% and a frequency of 14.7 GHz.