In this article, for the first time, the shielding of orbital angular momentum (OAM) waves by a cavity with apertures is evaluated. This is particularly interesting because the distinguishing feature between the OAM modes is their phase distribution in space, and, hence, shielding effectiveness is a mode-dependent phenomenon. A perfectly electrically conducting cavity with multiple apertures and two OAM antennas, inside and outside the cavity, is investigated using a method of moments based tool. The behavior of OAM waves is analyzed by comparing the transmission between the OAM arrays for different cases, including their field patterns in front of and behind the apertures. The effects of the orientation and position of the transmitting antenna, the rotation, size, and form of the apertures and different cavities are explored. Additionally, the effect on the distance and the orientation angle of the outer antenna are studied. It is shown that the propagation of OAM waves through apertures is possible and that the resulting signal loss is similar to the loss of a plane wave or the field of a monopole. It is also shown that certain OAM waves penetrate the apertures better than others.

中文翻译：

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带孔径空腔对轨道角动量波的屏蔽


在本文中，首次评估了带有孔径的腔体对轨道角动量（OAM）波的屏蔽。这是特别有趣的，因为 OAM 模式之间的区别特征是它们在空间中的相位分​​布，因此，屏蔽有效性是一种依赖于模式的现象。使用基于矩的工具方法研究了具有多个孔径的完美导电空腔以及空腔内部和外部的两个 OAM 天线。通过比较不同情况下 OAM 阵列之间的传输（包括孔径前后的场模式）来分析 OAM 波的行为。探讨了发射天线的方向和位置、孔径和不同腔体的旋转、尺寸和形式的影响。此外，还研究了外天线对距离和方向角的影响。结果表明，OAM 波可以通过孔径传播，并且产生的信号损失类似于平面波或单极子场的损失。研究还表明，某些 OAM 波比其他波更好地穿透孔径。