提出了X波段双频两段式同轴相对论返波振荡器的物理模型,推导了该结构在冷腔时的TM0n模式色散方程,数值求解了两段式同轴波纹慢波结构TM01模色散曲线;用粒子模拟软件对其结构和电磁参数进行分析研究,优化得到的结构参数为第一、二段分别为10个和4个周期数,周期长度分别为0.50 cm和 0.73 cm,波纹幅值分别为0.13 cm和0.21 cm,平均半径为2.9 cm,同轴间隙为2.1 cm。结果表明:在环形相对论电子注电压为510 kV、电流为9.4 kA,引导磁场为0.7 T的条件下,器件得到了X波段稳定的高功率双频微波输出,其平均功率约为0.75 GW,平均功率效率为15.6%。

Physical model for the X-band dual-frequency coaxial relativistic backward wave oscillator(RBWO) was suggested. The dispersion equation and the dispersion properties of the coaxial SWS were numerically investigated. The properties of dual-frequency RBWO were investigated and optimized with electromagnetic simulation method. The optimized parameters are as follows: corrugation period numbers are 10 and 4,corrugation periods are 0.50 cm and 0.73 cm,and corrugation amplitudes are 0.13 cm and 0.21 cm for the first and the second sections respectively. The average radius of slow wave structure is 2.9 cm. The results show that steady dual frequencies microwave power outputs are generated with operating voltage of 510 kV,beam current of 9.4 kA and external guiding magnetic field intensity of 0.7 T. The microwave frequencies are 9.367 GHz and 9.717 GHz. The averaged output power is 0.75 GW with efficiency of 15.6%. The power difference is about 0.14 dB.