[已解决]关于CST realized gain的计算, CST提供的答案好像有问题~望有经验的人士解答一下,谢谢

realized gain=gain * (1 - S11^2) ;Vc|3  
Dw7Xy}I/  
在CST里面, 假如频率是470mhz, 我的天线模拟后的结果是 4bp})>}jB  
tot.effic是-15.03 dB, Directivity=2.205 dBi, Gain(IEEE)= -3.144 dB, }% q-9  
realized gain= -12.83 dB,  (感觉比正常小很多) H<n"[u^@E  
S11=-3.0696 dB, v*qbzW`  
L'S,=NYXY  
想请教一下大家,这个cst里面的realized gain是怎么求出来的啊,按照CST给的结果,应该是tot.effic跟dir相加就得出来,但如果用公式,怎么也求不出来啊. 4oH ,_sr  
>p@b$po  
请 .. D*[Jrq,  
)gSqO{Z  

未注册仅能浏览部分内容，查看全部内容及附件请先 登录 或 注册

引用楼主xiaosampson于2009-12-01 19:03发表的 关于CST realized gain的计算, CST提供的答案好像有问题~望有经验的人士解答一下,谢谢 : P}Ig6^[m\  
realized gain=gain * (1 - S11^2)
在CST里面, 假如频率是470mhz, 我的天线模拟后的结果是 SdlO]y9E  
tot.effic是-15.03 dB, Directivity=2.205 dBi, Gain(IEEE)= -3.144 dB, B1}i0pV,,  
realized gain= -12.83 dB,  (感觉比正常小很多) Wm
d@%K  
....... EcH
Zmf  

w@-G_-6W  
epnZGz,A  
rlzd gain是计及匹配情况的增益，因而要按照你给的第一个式子计算

引用第1楼drunkbear于2009-12-02 09:42发表的  :
rlzd gain是计及匹配情况的增益，因而要按照你给的第一个式子计算 |h $Gs2  

-!+i ^r
 
{@KLN<  
谢谢你的回答,现在问题是,怎么也求不出CST给的答案. +jrx;xwot  
=Jl\^u%H(x  
现在初步怀疑它给的答案不正确,也有可能是我的计算方法错.

I found out the problem. If the antenna includes the extra real components rather than antenna itself, the gain shown in CST is the gain for the antenna, not the gain to calculate the realized gain. O8hx}dOjA  
60~*$`  
z]g#2xD2  
MkVv5C  
For example, iJ58RY  
|8}y?kAC  
In my case, 
5%(  
>%6j-:S  
Total Efficiency: -15.03 dB 9hK8dJw  
>;G_o="X  
Directivity: 2.205 dBi rMG[,:
V  
;woK96"{t  
Gain (IEEE): -3.144 dB im<!JMI  
iU.` TqR7  
Realized Gain: -12.83 dB ;Uch  
GX19GI@k  
Radiation Efficiency: -12.10 0e>?!Z E  
K'8o'S_bF  
A["6dbvv  
S11 for 470 MHz: -3.0696 dB %zc.b  
&z3_N  
hK4ww"-  
Realized Gain=Gain * (1 - S11^2) f4<~_ZGr  
mKM[[l&A  
KX x+J}n  
You can see that, the Gain (IEEE) is not equal to Directivity + Radiation Efficiency. ;xTMOuI*  
Q +hOW-  
,^4"
e (  
If we use the gain calculated by the equation, then we can get the same realized gain shown in CST. >*/ |tL  
T\zn&6