在微波技术向太赫兹波段推进过程中,人们关注的核心问题是器件的频率、效率或功率问题。文章从Maxwell方程出发,对两腔微波振荡器的束流动力学与束-波转换效率进行了讨论。在经典力学框架内,把电子相位运动方程化为摆方程;从系统的相平面特征出发,讨论了器件的接受度和束-波转换效率。结果表明,当相空间密度均匀分布时,相面积越大束流越强,功率越高;而能散越大束-波作用越强,转换效率越高。 In the microwave technology to promote the terahertz band, people are concerned about the core issue is the frequency of the device, efficiency or power problems. Starting from the Maxwell equation, the article discusses the beam dynamics and the beam-to-wave conversion efficiency of a two-cavity microwave oscillator. In the framework of classical mechanics, the electronic phase motion equation is transformed into a pendulum equation. Based on the phase-plane characteristics of the system, the acceptability of the device and the beam-to-wave conversion efficiency are discussed. The results show that when the phase space density is uniformly distributed, the larger the phase area is, the stronger the beam current is, and the higher the power is, and the larger the beam-to-beam effect is, the higher the conversion efficiency is.