回旋速调管加载损耗介质群聚腔的研究

 用模式场匹配理论建立了散射矩阵，数值模拟并分析了加载损耗介质层对群聚腔Q值、谐振特性以及群聚腔两端漂移段半径的大小对谐振特性的影响。研究表明：加载损耗介质在高频率下使群聚腔主要寄生模式EH₂₁₂和EH₃₁₁得到极大的抑制，对工作模式H₀₁模更有利；衰减常数随损耗层厚度的增加而迅速增加，Q值随介质厚度的增加迅速减小,因此在设计腔体时必须严格控制损耗材料厚度。最后为正在研制的回旋速调管设计了满足要求的低Q群聚腔，该腔冷测实验结果与计算结果基本一致。

Bunching cavity with dielectric absorber for gyroklystron

The bunching cavity with dielectric absorber for gyroklystron is studied by using the mode-matching technique to build scattering matrix. By the theoretical analysis and the numerical simulation, the effect of loss dielectric absorber on Q factor and resonance characteristic of bunching cavity , and the effect of side apertures on resonance characteristic are presented . The numerical simulation shows that the bunching cavity with loss dielectric absorber can bate parasitical EH212 mode and EH311 mode effectively, but profit H01 mode at 8 mm band. When the thickness of loss dielectric absorber increases, the quality factor Q will decrease. Cold-test shows that the simulation results are in good agreement with experimental results.