摘要
指出了只有针对具有特定频率和波矢的一列电磁波定义能速才有明确意义,并对此作些说明和论证.通过计算无界线性介质和典型传输线中电磁波的平均能速和相速,得出结论:当电磁波在线性介质中以横电磁波(TEM)模式传播时,其平均能速总是等于相速;若在传输线中以横电波的mn模(TEmn)或横磁波的mn模(TMmn)传输时,其平均能速在波阵面上各点的大小不同,且都小于相速和真空光速.
It was pointed out that the definition of energy velocity has clear meaning only for a ray of electromagnetic waves with definite frequency and wave vector.Then,some explanation and proof were provided.By calculating the average energy velocities and the phase velocities of electromagnetic waves in boundless linear media and typical transmission lines,it arrives at the conclusion that：when the electromagnetic wave propagates through linear media by TEM mode,the average energy velocity equals the phase velocity;if electromagnetic waves are transmitted by the TEmn mode or TMmn mode through a transmission line,the average energy velocity is variable on the wave front,and it is always lower than the phase velocity or the speed of light in the vacuum.
出处
《广东工业大学学报》
CAS
2012年第1期1-4,共4页
Journal of Guangdong University of Technology
基金
国家自然科学基金资助项目(60671060)
广东工业大学教育教学改革重点项目(2010Z015
2010Z019)
关键词
一列电磁波
能速
相速
传输线
传输模式
a ray of electromagnetic waves
energy velocity
phase velocity
transmission lines
transmission mode
