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因孔缝的存在屏蔽腔防护性能在谐振点处被大幅度弱化,现有文献多单以屏蔽效能(SE)作为测算点,对于电磁能量与PCB上MSL耦合而产生感应电流(Current)的计算没有给予足够关注。有鉴于此,建立内置带MSL的PCB开缝壳体等效计算模型,在模型有效性验证后,使用有限元法研究平面波激励下,MSL端接负载、孔缝尺寸、PCB尺寸及位置等参数变化对SE和Current的影响。结果表明:Current和SE虽然幅值变化不同,但曲线走势具有一定的对称性,尤其是谐振频点处;负载取值不同对结果没有影响;孔缝长宽尺寸变化对第二谐振有明显影响,取值增大频点左移是共性,且受长度影响更明显;PCB长宽尺寸增加,第一谐振左移是共性,且频移幅度受宽度影响更大,PCB宽度越大,第二谐振被激发出的可能性也变大;PCB等值靠近左壁,第一谐振等频右移,第二谐振等频左移。
Due to the presence of holes, the shielding performance of the shielding cavity is greatly weakened at the resonance point. In the existing literature, the shielding effectiveness (SE) is taken as the calculation point only. The calculation of the induced current (Current) due to the electromagnetic energy coupling with the MSL on the PCB Did not give enough attention. In view of this, the built-in calculation model of PCB slotted shell with built-in MSL is established. After validating the model, finite element method is used to study the parameters of MSL termination load, aperture size, PCB size and position under plane wave excitation Impact of changes on SE and Current. The results show that although the current and SE vary in amplitude, the trend of the curve has a certain symmetry, especially at the resonance frequency; the different load values have no effect on the result; the change of the slot length and width has a significant effect on the second resonance , The value of the increase of frequency shift to the left is common, and more affected by the length; PCB length and width dimensions increase, the first resonance left shift is common, and the frequency shift amplitude greater impact by the width, the greater the PCB width, the second The possibility of resonant excitation is also greater; PCB equivalent value near the left wall, the first resonant frequency shift right, the second resonant frequency shift left.