[分享]Time Domain Analysis Using TimeFEKO

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Time Domain Analysis Using TimeFEKO u!D?^:u=)  
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图片:timefeko_thumbnail_small.jpg

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http://www.feko.info/feko-product-info/technical/special-module-and-feature-articles/timefeko KX~ uE6rX  
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Brief description on how TimeFEKO can be used to get time-domain information from FEKO. O~qRHYv  
FEKO is based on a frequency domain formulation. Time-domain information can however be obtained by applying Fourier Transforms on broadband frequency-domain data. The specification of time-domain pulse shapes and the required frequency domain simulations is automated by the TimeFEKO module. Z0Sqw  
Available Pulse Forms -Ct+W;2  

• Gaussian 6<W^T9}v@/  
  
• Ramp )q_,V"  
  
• Double exponential !QwB8yK@  
  
• Triangle. :;Z/$M16B  
  

Example: <~uzHg%Y  
The time domain response of the mono-static scattered electric field (Ez) is to be determined for a Gaussian pulse illuminating a cube along the x-axis. YaS!YrpI  
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Surface currents at 250 MHz. C'[4jz0xF  
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图片:TIMEFEKO_model.gif

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feko能够设置高斯普？ g6T /k7a  
那的确很爽，能不能设置锥面柱的激励呢？

引用第2楼ham119804于2008-11-09 23:19发表的 : mnM!^[|z  
feko能够设置高斯普？ .v3~2r*&  
那的确很爽，能不能设置锥面柱的激励呢？

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不是很清楚....锥面柱的激励 3K57xJzK  
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但是這是在時域下才可以做.

*.tim input file 跟 Defining the pulse form j7vp@l6`L  
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25 The program TIMEFEKO \k{UqU+s  
25.1 Description l%?D%'afN  
With the program TIMEFEKO electromagnetic scattering problems can be solved in the m8q3Pp  
time domain. It is based on the program FEKO (that does the relevant calculations in the $ePBw~yu  
frequency domain) and an FFT algorithm (that transforms the data to the time domain). Ri@`sc{n  
For the excitation a number of different pulses have been pre-defined and stored in the +6=2B0$ r  
function library (see section 25.3.1). ,1"w2,=  
The program TIMEFEKO is constructed in such a way that all the data in the output )19As8rL/o  
file (*.out) from FEKO is transformed, i.e. in the input file the cards have to be specified idLysxN  
in the correct way to ensure that the correct data is transformed. Information on the ^ $M@yWX6  
correct card definitions is given in the following section. |=7ouFl  
The program TIMEFEKO uses two input files,10 that have to be created by the user. K; 7o+Xr  
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25.3 The *.tim input file 5YlY=J  
In the file *.tim the pulse form, position and the point in time are assigned. This file Kp+Lk  
consists of a number of sections which are optional at present. [/}y!;3iXM  
• Set the pulse form with characteristic value and the time shift. ^rI<}cfR  
• Set the value of the highest frequency and the sampling points. Md9b_&'  
• Set the normalisation (normalise time to the speed of light). . mDh9
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• Set whether the output is written to the output file. l^s\^b
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• Set the time points. *RQkL'tRf  
In the *.tim file, empty or comment lines (starting with **) are allowed. The parameters Zc"Vf]:  
need not be entered in any particular column, but they have to be in the correct order. l:O6`2Z  
The keywords used in the *.tim file exist in German and English (for example ANREGUNG &R54?u^A  
and EXCITATION). Both versions of each keyword will be given in the discussion below. { jnQoxN  
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25.3.1 Defining the pulse form oJ cR)H  
The assignment of the pulse form is necessary. Each pulse has a predefined 5} 9}4e  
particular characteristic parameters. The parameters must be assigned absolute 6t0!a@t  
and not normalised values. The amplitude factor u0 is 1. It can be changed D:9/;9V  
Ax card (in the file *.pre) with the appropriate amplitude value. xS) njuq4  
Time shifting t0: indicates the time (in seconds) that the pulses are delayed 2 0Xqs,  
in Figure 25-1). The time shift should be such that the excitation of the (o/HLmr@Y  
t = 0 is approximately 0. Since both the time and frequency domain data 47R4gs#W  
this is not strictly required, but it simplifies working with the results. Y"GU"n~  
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1. Gaussian pulse GAUSS / GAUSS (see Figure 25-2) }s_'
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Example: Th&* d;  
** Pulse form ESk<*-  
GAUSS V0Cz!YM_3  
** t0 Exponent a 9]AiaV9  
2.0E-08 3.0E+08 y9?~^pTx  
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2. Triangular pulse DREIECK / TRIANGLE (see Figure 25-3) qc}r.'p  
Example: -_bHLoI  
** Pulse form >^#OtFHuT)  
TRIANGLE lMu}|d  
** t0 Impuls Duration T B
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2.0E-08 1.0E-08 5:mS~  
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3. Double exponential pulse DEXP / DEXP (see Figure 25-4) Lw 7,[?,Z  
Example: #On EQ:  
** Pulse form ,?"cKdiZ  
DEXP _~aFzM
 
** t0 T tau1 tau2 D|W^PR:@h  
0.0 10.0E-09 5.0E-9 10.0E-9 -jc8ku3*  

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4. Ramp pulse RAMPE / RAMP (see Figure 25-5) 6&o9mc\I  
Example: $MF U9<O  
** Pulse form =Rl?. +uE  
RAMP IL?mt2IQ>  
** t0 Impuls Duration T tau1 tau2 'iM;e K  
20.0E-09 15.0E-09 5.0E-09 10.0E-09 Ih*}1D)7  
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5. Double exponential impulse (second type) DBLEXP / DBLEXP (see Figure 25-6) <$#b3F"I  
Example: ,6,sz]3-  
** Impulse form >E;-asD  
DBLEXP -c-#1_X5  
** Time. t0 Parameter tau1 Parameter tau2 ?dJ-g~  
20.0E-9 70.0E-9 5.0E-9

开始还认为是时域积分方程求解，原来傅氏变换来的

如果能把fdtd的功能加入进来 SH>L3@Za  
估计用的人会更多

引用第5楼cem-uestc于2008-11-10 16:28发表的 : yWI30hW  
开始还认为是时域积分方程求解，原来傅氏变换来的

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感謝 cem-uestc 的關注... g)7~vm2/,
 
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目前是 傅氏变换来.... 沒錯.... 頻域的東西就是如此.... 但是至少讓使用者可以轉到時域下去觀看他想看的問題. )!+M\fT  
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目前還沒 FDTD Code 加入.這是明確的....以後也許會有...

這是明確的....以後也許會有... C3K":JB  
webhugo 语法有问题  哈哈

引用第8楼ham119804于2008-11-11 09:59发表的 : g_JSg
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這是明確的....以後也許會有... wu.>'v?y  
webhugo 语法有问题  哈哈 [表情]

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抱歉..也就是說 ....  目前僅有 MOM, FEM, UTD, PO, GO, MLFMM, GA ... xC9?Wt'  
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但是沒有 FDTD Code..... wzF%R{;  
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目前想要看  Time Domain 僅能透過 Fourier Transforms ... (跟 網路分析儀一樣...都是需透過轉換) 'A,)PZL9i  
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FEKO is based on a frequency domain formulation. Time-domain information can however be obtained by applying Fourier Transforms on broadband frequency-domain data.