In this work, to characterize the radiated emission from electronic circuits in shielding enclosure, an improved electric dipole-based source reconstruction method (SRM) is developed. Moreover, by resorting to this reconstructed equivalent source, the estimation of electromagnetic interference (EMI) between different circuit modules in the enclosure can be conveniently and accurately evaluated. Different from the free-space SRM, the equivalent dipoles of the proposed SRM are directly placed over the shielding box enclosed circuit board, and the numerical Green’s function (NGF) is developed to bridge the connection between the equivalent dipoles and the planar scanned magnetic near-field. With the NGF strategy, the effects of surrounding environments (including the presence of substrate, ground plane, and shielding enclosure) are inclusively considered, which makes the proposed SRM valid for any complex EM environments in theory. Since the proposed SRM also has the capability of reproducing the radiated emission inside the shielding enclosure, it is critically helpful to evaluate the EMI between different circuit modules inside the shielding enclosure. To reach this aim, the Rayleigh-Carson Reciprocity theorem is referred, in which the original EM coupling problem is decomposed into the “forward problem” and “reverse problem.” A Huygens box enclosing the victim circuit module is built and the EM fields on the box are obtained using the reconstructed dipoles in both problems. Then the EMI can be calculated accordingly. Therefore, the novelty and merits of the proposed approach are threefold: 1) the physically-based equivalent dipole model considers the interactions between the radiation sources and the surrounding objects, leading to the accurate prediction of radiated emissions both outside and inside the enclosure; 2) due to the utilization of the NGF, there is no approximation involved in the solution of the dipole’s radiation, thus improving the calculation precision; and 3) the near-field coupling between multiple electronic circuit modules inside the shielding enclosure can be identified precisely, which is useful for diagnostics of radiation sources. The effectiveness of this algorithm is verified by representative numerical examples.

中文翻译：

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基于数值格林函数的屏蔽罩电子线路源重构及其在电磁干扰估计中的应用


在这项工作中，为了表征屏蔽外壳中电子电路的辐射发射，开发了一种改进的基于电偶极子的源重建方法（SRM）。此外，利用这种重构的等效源，可以方便、准确地评估外壳内不同电路模块之间的电磁干扰（EMI）。与自由空间SRM不同，所提出的SRM的等效偶极子直接放置在屏蔽盒封闭的电路板上，并且开发了数值格林函数（NGF）来桥接等效偶极子和平面扫描磁近场之间的连接。 -场地。通过 NGF 策略，周围环境（包括基板、接地平面和屏蔽外壳的存在）的影响被全面考虑，这使得所提出的 SRM 在理论上适用于任何复杂的电磁环境。由于所提出的 SRM 还具有再现屏蔽外壳内辐射发射的能力，因此评估屏蔽外壳内不同电路模块之间的 EMI 至关重要。为了达到这个目的，引用了瑞利-卡森互易定理，将原来的电磁耦合问题分解为“正向问题”和“逆向问题”。构建了一个封闭受害电路模块的惠更斯盒，并使用两个问题中的重建偶极子获得了盒上的电磁场。然后可以相应地计算EMI。 因此，该方法的新颖性和优点有三个：1）基于物理的等效偶极子模型考虑了辐射源与周围物体之间的相互作用，从而可以准确预测外壳外部和内部的辐射发射； 2）由于NGF的利用，偶极子辐射的求解不涉及近似，提高了计算精度； 3）可以精确识别屏蔽外壳内多个电子电路模块之间的近场耦合，这有助于辐射源的诊断。通过有代表性的数值算例验证了该算法的有效性。