对电磁波从辐射近区到远区特性的分析
ANALYSIS OF THE CHARACTERISTICS OF ELECTROMAGNETIC WAVE RADIATION FROM THE NEAR ZONE TO THE FAR ZONE
肖儿良 1刘婉 1周征洋 1艾聪1
作者信息
- 1. 上海理工大学光电信息与计算机工程学院,上海 200093
- 折叠
摘要
在大学物理关于电磁波辐射的教学中,重点讲解了电磁场在辐射近区和远区的特点.同学们认识到,对电偶极辐射,在辐射源附近,电场是与静场类似的纵波,而在远离辐射源的区域电磁波是横波.电场是怎样从纵波过渡到横波的呢?这个过渡区较为复杂,一般教科书上都没有仔细讲解,但这又是同学们非常关注的一个问题.因此,本文对电偶极、磁偶极和电四极辐射作了较完整的分析,并详细计算了电偶极辐射的电场从近区到远区的过程中,电场的纵向分量与横向分量的比值的变化,清晰地显示了从近场到远场的过渡过程.
Abstract
In the teaching of electromagnetic wave radiation in university physics,the focus is on explaining the characteristics of the electromagnetic field in the near and far zone of radia-tion.Students realize that in the case of electric dipole radiation,the electric field is a longitu-dinal wave similar to a static field near the radiation source,while in the region far from the radiation source,the electromagnetic wave is a transverse wave.How does the electric field transition from a longitudinal wave to a transverse wave?This transition zone is quite complex and is generally not explained in detail in textbooks.However,this is a question that students are very concerned about.Therefore,this article provides a detailed analysis of electric dipole,magnetic dipole,and electric quadrupole radiation,and calculates in detail the change in the ratio of the longitudinal component to the transverse component of the electric field during the process of electric dipole radiation from the near zone to the far zone,clearly showing the tran-sition process from the near field to the far field.
关键词
电磁波辐射/纵场/横场Key words
electromagnetic wave radiation/longitudinal wave/transverse wave引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据