Time-domain nature of group delay

作     者：王建武 冯正和 Wang Jian-Wu;Feng Zheng-He

作者机构：Department of Electronic EngineeringTsinghua University Air-force Air-born Academy 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2015年第24卷第10期

页      面：36-40页

核心收录：

学科分类：07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 070104[理学-应用数学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0701[理学-数学] 

基　　金：Project supported by the National Basic Research Program of China(Grant No.2013CB329002) the National Natural Science Foundation of China(Grant No.61371012) 

主　　题：energy center group delay time domain superluminality 

摘      要：The characteristic of group delay is analyzed based on an electronic circuit, and its time-domain nature is studied with time-domain simulation and experiment. The time-domain simulations and experimental results show that group delay is the delay of the energy center of the amplitude-modulated pulse, rather than the propagation delay of the electromagnetic field. As group velocity originates from the definition of group delay and group delay is different from the propagation delay, the superluminaiity or negativity of group velocity does not mean the supeduminal or negative propagation of the electromagnetic field.