時域求解微帶天線不同設置對VSWR的影響
天線微帶設置影響CST時域求解微帶天線時，為什么solver setting中不同的Accuracy得到的VSWR不同呢？出現這種情況可能是什么原因呢？
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Accuracy of the calculated S-Parameter
The S-parameters can only be as accurate as the signals they were calculated from. This means that, theoretically, the S-parameters are only exact if the time signals have entirely come down to zero. Otherwise, information about the system will be lost that would be needed for exact transfer functions.
However, in the simulation, the time signals will never come down. Even when the fields have been propagated entirely through the structure, numerical errors will prevent the signals from reaching zero. At this time, where the signals contain only numerical noise, the simulation should stop because the signals contain no further information about the system. Therefore, a criterion must be found to decide when numerical noise starts to dominate. Also, this criterion should be variable to save simulation time if a lower accuracy is needed.
能把不同的結果放上來大家看看嘛
之前密碼想不起來了，今天終于試出來了，附件中是分別設置為30dB和40dB得到的不同結果，期待大俠解答！
Let see these figures:
-30 dB Accuracy
-40 dB Accuracy
It is quite clear that both of the simulations have the same resonance frequencies at about 4 GHz, 8 GHz, 10 GHz, and 18 GHz and nearly the same S11 level through the whole frequency range. Therefore, the different accuracy level does not affect the simulation results on the electro-magnetic properties.
However, the second figure (-40 dB accuracy) has much "smoother" S11 curve than the first one (-30 dB accuracy) from 4 GHz to 7 GHz. Furthermore, the higher accuracy criterion simulation means lower numerical noise level then improve the S11 resonance performance at 4 GHz and 10 GHz.
According to the above, higher accuracy level need longer field analysis time for the energy to be degraded to the noise level. So, if you check the slover log you should notice that the -40 dB accuracy simulation takes longer duration than -30 dB accuracy simulation.
長見識了，謝解答
域求解微帶天線時，為什么solver setting中不同的Accuracy得到的VSWR不同呢？出現這種情況可能是什么原因呢？
如果你把網格再加密的話，采用自適應網格的話，將會得到不同的VSWR，不同的網格設置和精確度肯定得到不同的VSWR，關鍵是看VSWR的差異，如果變化比較小，那就說明誤差已經很小了。
仿真的誤差分析在CST的初級教程里面講的很清楚，建議樓主查找資料看看。
恩，明白了，多謝解釋哈
好的，多謝，正在補這些基礎知識
