CST realized gain的計(jì)算問題

realized gain=gain * (1 - S11^2)
在CST里面, 假如頻率是470mhz, 我的天線模擬后的結(jié)果是
tot.effic是-15.03 dB, Directivity=2.205 dBi, Gain(IEEE)= -3.144 dB,
realized gain= -12.83 dB,(感覺比正常小很多)
S11=-3.0696 dB,
想請(qǐng)教一下大家,這個(gè)cst里面的realized gain是怎么求出來的啊,按照CST給的結(jié)果,應(yīng)該是tot.effic跟dir相加就得出來,但如果用公式,怎么也求不出來啊.
請(qǐng)哪位高人解答一下謝謝

rlzd gain是計(jì)及匹配情況的增益，因而要按照你給的第一個(gè)式子計(jì)算

謝謝你的回答,現(xiàn)在問題是,怎么也求不出CST給的答案.
現(xiàn)在初步懷疑它給的答案不正確,也有可能是我的計(jì)算方法錯(cuò).

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.
For example,
In my case,
Total Efficiency: -15.03 dB
Directivity: 2.205 dBi
Gain (IEEE): -3.144 dB
Realized Gain: -12.83 dB
Radiation Efficiency: -12.10
S11 for 470 MHz: -3.0696 dB
Realized Gain=Gain * (1 - S11^2)
You can see that, the Gain (IEEE) is not equal to Directivity + Radiation Efficiency.
If we use the gain calculated by the equation, then we can get the same realized gain shown in CST.