CST中材料參數的設定？

來源：edatop 更新時間：2024-09-07 閱讀：

我目前是在模擬PCB,
關於基底(substrate)的部份,選的材料是FR4 (Er =4.2 , loss tanget = 0.02),
想問的是在FR4材料裡,Material Parameter / Conductivity 這個頁面,
關於Tangent delta electric(我輸入0.02) ,針對 at frequency:?
想問這個頻率點要如何選取,我模擬的頻寬10G(0~10)
謝謝各位的幫忙 ^ ^！

,這邊有圖例0.0..

貌似是中心頻點吧，材料在不同頻率下的損耗角正切，我想可能是工作的中心頻點，小編查閱下幫助文檔看看有沒有解決方法，我也看一下

Electric conductivity frame
Electric conductivity: Activating this radio button defines a conducting material based on the model of a constant electric conductivity value.
Tangent delta electric: Activating this radio button offers the possibility to define different loss models based on electric tangent delta values.
Specification: Three different electric tangent delta specifications are available:
Const. Conductivity: This model corresponds to a material possessing a constant conductivity as mentioned above, but is defined by the input of an electric tangent delta value given at a specific frequency.
Const. fit tan delta: This specification is based on the model of a first order Debye dispersion, defined again by the input of an electric tangent delta value given at the defined frequency. As mentioned above, at this frequency point the real part of the permittivity equals the epsilon input on the Material Parameter - General page. Please note that a perfectly constant tangent delta does not exist in reality; however, the broadband behavior of this formulation represents an almost constant tangent delta curve.
Dispersion fit tan delta: The dispersion fit is based either on a constant conductivity or a General 1st order model. Now more than one tangent delta value may be defined for different frequency points by pressing the Dispersion List… button. Again, the real part of the permittivity is given by the epsilon input on the Material Parameter - General page. Please note that due to the frequency dependent material behavior the values correspond only at the center frequency.

Magnetic conductivity frame
Magnetic conductivity: Activating this radio button defines a conducting material based on the model of a constant magnetic conductivity value.
Tangent delta magnetic: Activating this radio button enables the input of a magnetic tangent delta value given at specific frequency.
Specification: Three different magnetic tangent delta specifications are available:
Const. Conductivity: This model corresponds to a material possessing a constant conductivity as mentioned above, but is defined by the input of a magnetic tangent delta value given at a specific frequency.
Const. fit tan delta: This specification is based on the model of a first order Debye dispersion, defined again by the input of a magnetic tangent delta value given at the defined frequency. As mentioned above, at this frequency point the real part of the permeability equals the mue input on the Material Parameter - General page. Please note that a perfectly constant tangent delta does not exist in reality, however, the broadband behavior of this formulation represents an almost constant tangent delta curve.
Dispersion fit tan delta: The dispersion fit is based either on a constant conductivity or a general 1st order model. Now more than one tangent delta value may be defined for different frequency points by pressing the Dispersion List… button. Again the real part of the permeability is given by the mue input on the Material Parameter - General page. Please note that due to the frequency dependent material behavior the values correspond only at the center frequency.

Frequency range frame
Fmin/Fmax: These text fields are for information purposes only. They show you the minimal and maximal chosen frequency. To change these values you may go into the frequency range settings in the main menu under Solver Frequency....

我也有看過Help裡面的手冊說明,都沒有說如何選取頻率點XD
可能就如小編所說的,取中心頻率點囉！
謝謝

不謝，一般情況下，我很少設置這個，所以不是很清楚，希望小編能給予解答下

我來說明下，主要針對這個選項的第二、三項第二項名為恒定損耗正切角，意義為模擬在整個頻段上的損耗正切角為恒定值，其實實際中這是不現實的，因此CST中也只是近似的將中心頻點處的損耗正切角值定位設定的值，其余頻帶內可能近似地向這個值靠攏（其實也考不攏，呵呵）。如下圖