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.

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.Thenumerical 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.