TM610高次模圆柱谐振腔的模拟研究

 根据电磁场理论设计了S波段TM610高次模圆柱谐振腔。运用HFSS，ISFELD3D， CST-MS及MAFIA软件计算了该谐振腔中TM₆₁₀及其附近模式的电磁场分布、谐振频率及模式间隔。计算表明：TM₆₁₀模式的电磁场集中在漂移管头周围的区域，谐振腔中心处无电磁场分布。根据TM₆₁₀模式的特点，采取了在腔中心放置铁氧体微波吸收材料的方法来抑制杂模。HFSS模拟表明：腔内吸收材料可消除TM₅₁₀模式外大部分杂模的影响。采用了在主谐振腔外加耦合吸收腔的方法来抑制TM₅₁₀模式，该吸收腔基模TM₀₁₀的谐振频率等于TM₅₁₀的谐振频率。模拟表明：TM₅₁₀模式的大部分能量可以被吸收腔内的铁氧体材料衰减掉，Q值从15 604下降到571。

Simulation of TM610 higher-order mode cylindrical cavity

An S-band cylindrical cavity works on TM_(610) higher-order mode was designed on the basis of electromagnetic the-ory.Electromagnetic field distribution,frequency and mode spacing of TM_(610) mode and its adjacent modes were calculated by using HFSS,ISFELD3D,MAFIA and CST-MS.Simulation results indicate that the electromagnetic field of TM_(610) mode distributes in the section around drift tube,and there is no electromagnetic field in the center of the cavity.A ferrite RF absorber was set in the center of the cavity to suppress the non-work modes based on the characteristic of TM_(610) mode.Simulation results of HFSS show that most non-work modes are eliminated by RF absorber except the TM_(510) mode.An absorption cavity coupled to the main cavity was used to suppress the TM_(510) mode.Simulation results show that the absorption-cavity attenuated most energy of TM_(510) mode,and the Q value decreased from 15 604 to 571.