基于Vector Fitting的金属薄壳电磁脉冲屏蔽效能的计算

金属薄壳电磁脉冲屏蔽效能的计算是电磁兼容研究的基础。为评估金属薄壳电磁脉冲瞬态屏蔽效能,该文提出了一种任意波形激励情况下金属薄壳电磁脉冲时域响应的快速计算方法。该方法将金属薄壳频域屏蔽效能转移函数拟合为有理函数,根据拉氏逆变换性质,得到金属薄壳脉冲时域响应指数叠加的形式,从而采用递归卷积计算任意波形激励时金属薄壳的暂态屏蔽效能。该方法直接在时域内计算,避免了基于FFT(FastFourierTransformation)算法的时域频域转换;同时,采用递归卷积分格式,极大地提高了计算效率。通过与近似公式比较,证明了该方法比近似公式更为准确,计算速度更快。

Evaluation of EMP shielding effectiveness for metallic shells based on the vector fitting method

Many EMC problems require evaluation of the transient shielding effectiveness of the thin metallic shells. A fast time domain approach was developed to calculate the transient shielding effectiveness of thin metallic shells excited by an arbitrary waveform electromagnetic pulse. The frequency domain transfer function of the thin metallic shell is fit into a rational function using the vector fitting method, with the pulse response expressed as a sum of decay exponentials in the time domain from the inverse Laplace transformation. The transient shielding effectiveness excited by an arbitrary waveform can be easily obtained based on the recursive convolution formulation. The method is a time domain algorithm that does not require the time-consuming FFT analysis, and the recursive convolution can dramatically improve the calculational efficiency. The proposed approach is validated by numerical examples.