多注速调管TM_(310)模光子晶体谐振腔研究

The Study of TM_(310) Mode Photonic Crystal Cavity for Multi-Beam Klystron

研究了适用于多注速调管的TM310模光子晶体谐振腔,发现在此类谐振腔的缺陷中心放置单层光子晶体结构能抑制与主模临近的杂模。进一步研究发现,为了易于工程实现,在不采用光子晶体谐振腔的前提下,在谐振腔中放置单层光子晶体结构,亦能抑制与主模临近的杂模,并能增大主模与非工作模式的频率间隔。利用HFSS软件对X波段此类谐振腔进行了模拟计算,验证了该方法的有效性。

Three problems were studied for the coaxial output cavity operating at TM410 mode for multiple-beam klystron,which were the higher external Q-factor,the worse field distribution symmetry,and the small frequency interval between operating mode TM410 and neighboring modes.In order to resolve these problems,a coaxial output cavity with metallic rings and shorting bar is presented.Setting the shorting bar suitably can not only decrease external Q-factor,but also make field distribution uniform.Furthermore,inserting the metallic rings can enlarge frequency interval between operating mode and neighboring modes.This kind of coaxial output cavity in X-band operating at TM410 mode was modeled and simulated by CST-MWS.The frequency interval between TM410 mode and neighboring modes is enlarged to more than 1.3 GHz,the external Q-factor is diminished 42.7%(from 540.4 to 309.6),and the symmetry of the field distribution of TM410 mode is improved.