FDTD中色散介电常数的时域离散表达方法  

Discrete-Time Representation of Generalized Frequency-Dependent Permittivity within FDTD

作　　者：张晓光[1,2] 苏治国[3] 王忠青[1] 阮殿旭[1] 

机构地区：[1]中国矿业大学机电工程学院,江苏徐州221116 [2]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071 [3]爱尔兰国立都柏林大学电气,电子及机械工程学院,都柏林4

出　　处：《中国矿业大学学报》2010年第3期391-394,共4页Journal of China University of Mining & Technology

基　　金：中国博士后科学基金项目(20060390277);江苏省高技术研究项目(BG2007013);综合业务网理论及关键技术国家重点实验室开放课题项目(ISN10-10)

摘　　要：针对递归卷积方法只适合于随频率变化比较平滑的色散介电常数情况,提出一种可以把色散(频变)介电常数直接嵌入时域有限差分的算法(FDTD).将随频率变化的色散介电常数用Debye有理函数近似,修正后的离散冲激响应用非等步长的离散时域表达直接和FDTD算法进行卷积.结果表明:用此方法的仿真结果和用递归卷积方法仿真的结果进行比较后发现2种仿真结果吻合很好.表明该方法准确、稳定,适用于色散介电常数随着频率变化非常复杂的情况.Based on the recursive convolution method, which is only suitable for the dispersive media whose permittivity changes smoothly with the frequency, a direct algorithm incorpora- ting frequency-dependent permittivity into a finite difference time domain （FDTD） was presented. The frequency-dependent permittivity was approximated by a rational function Debye to obtain the simulation result. The same permittivity was represented as a non-uniform discretetime modified impulse response directly implementing a convolution in FDTD algorithm to obtain the simulation result. These two simulation results were compared and showed very good agreement. The proposed method is accurate and stable, and suitable for the case that the permittivity changing complex with frequency.

关 键 词：时域有限差分算法(FDTD) 非等步长 介电常数 卷积 

分 类 号：TN820[电子电信—信息与通信工程]