面向遮挡区域的近场波束聚焦的物理一致性评估
A Physically Consistent Assessment of Nearfield Beamfocusing into Occluded Regions
AI总结：
本文评估近场波束聚焦技术的合理性，发现部分遮挡区域视距策略更优，完全遮挡区域需物理一致的EM传播模型，艾里波束等复杂技术无明显优势。
AI中文摘要：
近期研究探索了针对辐射近场的复杂波束聚焦技术，部分研究表明艾里波束（Airy beams）等特定波束形状可实现电磁波（EM）在障碍物后方的高效传输。本文中，我们探究这类技术的额外复杂度是否具备合理性。我们区分了部分遮挡区域与完全遮挡区域：在常用艾里波束的部分遮挡区域，我们证明仅激活对接收端无遮挡视距（LoS）天线的简单视距策略接近最优，且复杂度远低于艾里波束，性能更优；在完全遮挡区域，我们指出精准波束聚焦需采用能捕捉衍射等传播效应的物理一致性电磁波传播模型，该模型可用后，最优波束聚焦策略存在闭式解，可直接计算。这些结果表明，艾里波束等复杂技术在面向遮挡区域的波束聚焦方面，相比更简单的替代方案几乎无优势。
英文摘要：
Recent work has explored elaborate beamfocusing techniques for the radiative nearfield, with some studies suggesting that certain beamshapes, such as Airy beams, can enable efficient electromagnetic (EM) wave transmission behind obstacles. In this letter, we ask whether the added complexity of such techniques is justified. We distinguish between partially and fully occluded regions. In the partially occluded region, where Airy beams are commonly employed, we show that a simple line-of-sight (LoS) strategy, which activates only antennas having an unobstructed view of the receiver, is near-optimal and outperforms Airy beams at substantially lower complexity. In the fully occluded region, we argue that accurate beamfocusing requires a physically consistent EM wave propagation model that captures propagation effects such as diffraction. Once such a model is available, however, the optimal beamfocusing strategy has a closed-form solution and can be computed directly. These results suggest that elaborate techniques, such as Airy beams, offer little benefit over simpler alternatives for beamfocusing into occluded regions.
