Parasitic-Mode-Suppressing Method in TM310-Mode Cylindrical Resonator for High Power Multi-beam Klystron
高功率多注速调管TM310模圆柱形谐振腔杂模抑制方法

A new parasitic-mode-suppressing method for TM310 mode (operating mode) cylindrical resonator is presented in this paper. In order to suppress TM020 mode, a receiving-antenna is set into the resonator, and then the expression for frequency offset is derived based on the electromagnetic theory. Furthermore, two conclusions can be obtained from the formula: frequency offset of a mode only depends on the mode’s electric field in the position of the receiving-antenna; setting the antenna suitably can make frequency offsets of TM310 mode and TM020 mode differently, so the frequency interval between TM310 mode and TM020 mode may be enlarged, which helps avoid the interference of TM020 mode in the TM310 mode resonator. On the other hand, short-circuit- pole-array set into the resonator is used to suppress the TM+310 mode. By means of CST-MWS, this kind of resonator in X-band is simulated, which shows the availability of the parasitic-mode-suppressing method.