O型同轴慢波器件的纵向模式选择研究

Selection of longitudinal mode for O-type coaxial slow-wave devices

利用S参数理论,研究了O型同轴慢波结构中最低工作模式对应各纵模的频率、场分布和Q值,并分析了慢波结构周期数对纵模的数目及各纵模Q值的影响。在此基础上提出在O型同轴慢波器件中使用同轴引出结构,可减少慢波结构周期数,不但使器件结构更为紧凑,还可避免纵模竞争,从而提高器件效率、稳定产生微波频率。最后利用PIC方法对理论分析进行了模拟验证。

By using the method of S-parameter, The frequency, field distribution and Q-factor of longitudinal modes in coaxial slow-wave structure（SWS） are investigated, and the influence of the period-number of SWS on the mode number and Qfactor of longitudinal modes are analyzed. It is proposed that the introduction of a well designed coaxial extractor to coaxial SWS devices can help to achieve the longitudinal mode selection and reduce the period-number of the SWS, which not only can make the devices more compact, but also can avoid the destructive competition between various longitudinal modes, therefore can enhance the efficiency and stabilize the frequency.