多腔回旋速调管中的调制腔采用内外腔同轴结构,对回旋电子注角向群聚起着关键作用.用场匹配理论及HFSS软件对调制腔冷腔特性进行了研究,对多种输入结构、耦合缝尺寸和方位、腔体长度、半径进行了模拟.分析表明,耦合狭缝中心线与输入波导轴线成45°,耦合缝长度达到0.72时,内外腔储能比值达到41.65;耦合缝尺寸对腔体Q值影响较大,但并非呈简单线性关系,并且Q值对缝长的变化比缝宽的变化要敏感得多;而狭缝尺寸变化对谐振频率的影响不大;计算了内外腔储能,得到了模式转换效率高、内外腔储能比高、性能优良的调制腔.

Modulator cavity of multi-cavitys Gyroklystron transforms the TE₄₁₁ mode in out cavity to TE₀₁₁ mode in inner resonant cavity through 4 slots,TE₀₁₁ mode is used to modulate the transverse velocity of gyroelectron beam.In this paper,an analysis of cold cavity is presented,HFSS code is used to simulate couple of structure variety accurately and revise approximate analysis.It shows ratio of inner cavity's energy storage to that of outer cavity is 41.65,when angle between coupling slots' midline & waveguide axis is 45°.Length of slots affects Q factor greatly while resonance frequency is insensitive to it,moreover,Q factor relate with length of slots more sensitive than width of them.Energy storage in coaxial cavity has been calculated.Based on a large number of calculations and simulations,the optimal modulator cavity meeting the requirement is designed.