基于时域抽样法的FDTD近远场变换  

FDTD Near to Far Field Transformation Based on Time-domain Sampling

作　　者：蒋长宏[1] 张云华[2] 

机构地区：[1]中国科学院研究生院,北京100049 [2]中国科学院空间科学与应用研究中心,北京100080

出　　处：《计算机仿真》2007年第10期103-106,共4页Computer Simulation

摘　　要：提出一种基于时域抽样法的近远场变换算法以改善经典时域近远场变换算法计算量大、计算速度慢的缺点。时域抽样法是基于这样一个事实:在时域近远场变换过程中不需要与时域有限差分计算同样的时间精度。在近远场变换前先对时域近场数据进行采样以减少数据的冗余,然后用改进后的算法进行近远场变换计算从而达到减少数据量、提高计算速度的目的。为验证本算法,以计算七元八木天线远场方向图为例进行算法说明,并与经典时域法进行比较,结果表明本算法在保证与经典法具有同样精度的前提下,减少了90%数据存储空间,同时提高计算速度80%。应用本算法可以为天线仿真优化设计、雷达散射截面(RCS)计算等提供一种快速的时域计算方法。A new algorithm： FDTD near-to far-field transform is proposed based on time-domain sampling to improve the classical time-domain near-to far-field calculation which consumes too much memory and CPU times.The new algorithm based on a fact of that it doesn＇t need such a fine time interval in time-domain near-to farfield calculation as finite-difference time-domain calculation.In order to reduce the memory storage and save the CPU time,first sampling the time-domain near-field data to reduce the data redundancy before the near-to far-field calculation,and using the improved algorithm to calculate the far-field pattern.To verify this algorithm,the new algorithm is compared with the classical method by calculating the far-field pattern of 7-element Yagi-Uda antenna,the result shows that the new algorithm has the same accuracy as the classical method,at the same time it can reduce the memory storage by 90% and save the CPU time by 80%.It will be a fast time-domain method in antenna optimization and radar cross section（RCS） calculation.

关 键 词：时域有限差分 近远场变换 八木天线 时域抽样 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]