[1]周百新,王思聪.利用FDTD与传输方程混合计算散射系数的方法[J].南京师范大学学报(工程技术版),2006,06(03):014-17.
　ZHOU Baixin,WANG Sicong.A Method to Calculate Scattering Parameters in Combination with FDTD Simulation and Transmission Equation[J].Journal of Nanjing Normal University(Engineering and Technology),2006,06(03):014-17.
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利用FDTD与传输方程混合计算散射系数的方法
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南京师范大学学报（工程技术版）[ISSN:1006-6977/CN:61-1281/TN]

卷:
06卷
期数:
2006年03期
页码:
014-17
栏目:
出版日期:
2006-09-30

文章信息/Info

Title:
A Method to Calculate Scattering Parameters in Combination with FDTD Simulation and Transmission Equation
作者:
周百新;王思聪;
南京师范大学电气与自动化工程学院, 江苏南京210042
Author(s):
ZHOU Baixin; WANG Sicong
School of Electrical and Automation Engineering,Nanjing Normal University,Nanjing 210042,China
关键词:
FDTD(时域有限差分);  传输方程;  散射系数;  存储量;  仿真时间
Keywords:
FDTD ( Fin ite-D ifference T im e-Dom ain) ;  transm ission equa tion;  sca tter ing param ete rs;  storag e space;  simu lation tim e
分类号:
TN811
摘要:
利用FDTD(F in ite-D ifference Tim e-Domain)方法分析天线等无耗传输线馈电问题的散射系数时,为了得到输入电压和反射电压的时域信号,必须将FDTD仿真程序重复运行两遍.这对计算域较大的问题来说要花费很长的仿真时间和占用较大的存储容量,而实际散射系数中用到的端口输入电压与激励信号在时域波形上必须完全一致,只不过因为输入端口取样位置的不同,输入电压相对于激励信号在时间上有所延迟.对于无耗传输线其反射电压的最大值与输入电压的最大值应该相等.因此,利用已知的输入电压取样位置和电磁波的传输速度,并结合无耗传输线的波动方程(电报方程),可以从理论上推导出输入电压的时域波形和表示方程.这样在计算散射参数时就不需要用FDTD仿真来获得输入信号,而只需要进行一次FDTD运算获得所需的反射信号即可.在此不仅推导出了无耗传输线上任意一点电压、电流的时域表达式,还利用它计算出了微带线馈电的矩形贴片天线和低通滤波器的散射参数,并与二次FDTD仿真获得的结果进行了对比,二者结果完全一致.但使用此方法使仿真时间和存储量都节约了一倍.
Abstract:
The FDTD sim ulation procedure must be run tw ice when it is used to calcu late the scatter ing param eters o f the antenna and othe r objects fed w ith the lossless transm ission line in order to obtain the tim e dom a in input vo ltage and output vo ltage distribution. Therefore, the larger the FDTD com putationa l dom ain is, the larger the sim ulation tim e and sto rage space is required. H owever, the input vo ltage distr ibution is only the vo ltage exc itation source delayed in tim e. On the lossless transm ission line, the re flection vo ltage is equal to the input vo ltage in the am plitude, so a fo rmu lation and the distr ibution of the input vo ltag e in tim e dom a in can be found in theo ry by using the distance from the observe po int to the exc itation source, electrom agne tic field propagating speed and the transm ission equation ( or te leg raph equation). The FDTD simu lation program needn’ t been run to obta in the inpu t vo ltage when the sca-t ter ing param eters are ca lcu la ted. In th is m e thod, the FDTD prog ram is on ly run once to ob tain the re flection vo ltage d istribution in tim e. This paper no t on ly g ives out the tim e dom a in equation of the input voltage and current on a po int of the lo ssless transm ission line, but a lso ca lculates the sca tter ing param eters o f a patch antenna and a low - pass fi-l ter w ith them ethod. The num erica l experim ents have shown that the m ethod in this pape r is in good agreem ent w ith that from the tw ice‘ s FDTD s imu lation. The storag e space and the sim ulation tim e are a ll reduced even to a half as usual.

参考文献/References:

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[ 2] TAFLOVE A, UMASHANKAR K R. The fin ite difference time doma in m ethod for electrom agne tic scattering and interaction prob lem s[ J]. J E lec trom agnW av es and App,l 1987, 1( 3) : 243-267.
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[ 4] SHEEN D M, SAM IM ALL. Applica tion o f the three-dim ensional finite-difference tim e-dom ain m ethod to the ana lys is o f planarm icrostr ip c ircuits[ J]. IEEE Trans onM icrow ave Theory and Tech, 1990, 38( 7): 849-857.

备注/Memo

备注/Memo:
基金项目: 南京师范大学” 211“学科建设经费资助项目( 1843202529 ).
作者简介: 周百新( 1957-) , 女, 副教授, 主要从事电子技术应用和电磁场的数值计算等方面的教学与研究.E-m ail:zhoubaix in@ n jnu. edu. cn
更新日期/Last Update: 2013-04-29