A recent study proposed a technique to mitigate the far-field emission and susceptibility of printed circuit boards (PCBs) with the use of a suspended metal loop. This article provides, with the help of the small-loop theory, a methodology to analytically predict and further estimate the electromagnetic field (EMF) distribution and level at very large distances from the emitting PCB (as is the case for CISPR radiated emission measurements up to 10 m test distances), where full-wave simulations and experiments are very challenging (if not impossible as a practical matter). The suitability of the methodology was assessed for various radiator size and frequency as well as the loop radius and configuration with respect to the emitting PCB. As proof-of-concept, full-wave simulations and measurements have been performed. The root-mean-squared error (RMSE) was considered as the measure of the accuracy between the analytical and full-wave numerical results. It has been demonstrated that, whatever the loop radius and/or position with respect to the radiating integrated circuit (IC), the proposed methodology can approximate the far-field EMFs with low RMSE values. Moreover, as far as the emitting IC is concerned, independently of its size and radiating frequency (except near the loop resonance), a good precision was achieved with the analytical model compared to the full-wave numerical analysis. Furthermore, the approach was found to be effective not only on-axis but also off-axis of the suspended conductor loop. Apart from the required computational power for full-wave simulations, thanks to the proposed methodology, it is possible to significantly reduce the huge difference in computational time for numerical (≫\gg30 min, depending on the distance) and analytical (<< few seconds, independently of distance) analyses.

中文翻译：

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通过将闭合导体环放置在芯片附近来估计远场衰减的分析方法


最近的一项研究提出了一种通过使用悬挂金属环来减轻印刷电路板 (PCB) 的远场发射和敏感性的技术。本文借助小环路理论提供了一种方法，用于分析预测并进一步估计距发射 PCB 很远距离处的电磁场 (EMF) 分布和水平（CISPR 辐射发射测量的情况就是如此）至 10 m 测试距离），其中全波模拟和实验非常具有挑战性（如果在实际情况下并非不可能的话）。该方法的适用性针对各种散热器尺寸和频率以及与发射 PCB 相关的环路半径和配置进行了评估。作为概念验证，已经进行了全波模拟和测量。均方根误差（RMSE）被认为是解析分析结果和全波数值结果之间精度的衡量标准。已经证明，无论环路半径和/或相对于辐射集成电路 (IC) 的位置如何，所提出的方法都可以近似具有低 RMSE 值的远场 EMF。此外，就发射IC而言，无论其尺寸和辐射频率（环路谐振附近除外），与全波数值分析相比，该分析模型获得了良好的精度。此外，我们发现该方法不仅在悬置导体环的轴上有效，而且在离轴上也有效。 除了全波模拟所需的计算能力之外，由于所提出的方法，可以显着减少数值（≫\gg30 分钟，取决于距离）和分析（<<）计算时间的巨大差异几秒钟，与距离无关）分析。