基于基因设计超散射体的巨量旋转微多普勒
Giant Rotational Meta-Doppler from Genetically Designed Superscatterers
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中文总结 AI 辅助
该研究通过协方差矩阵自适应遗传算法优化磁电阵列，设计出基因定制超散射体，实现巨量旋转微多普勒响应，提升了慢速运动的雷达探测性能。
中文摘要 AI 辅助
刚体与波相互作用时，其运动将留下光谱特征，其中多普勒频移是主要贡献项。由于任何运动都可分解为平移和旋转分量，旋转多普勒能提供关于物体动力学的额外信息。在电磁领域，旋转物体通常会产生旋转多普勒（或微多普勒）信号，该信号由散射过程的对称性和空间结构决定。对于亚波长或尺寸与波长相当的物体，其响应通常由最低阶偶极散射通道主导，因此主导光谱分量通常出现在角频率的两倍处。本文引入人工设计旋转微多普勒的概念，通过设计一种紧凑的强散射结构，该结构通过高阶多极共振级联工作，从而产生巨量增强效应。利用协方差矩阵自适应遗传算法，在GHz频段优化由强耦合电谐振器和磁谐振器组成的磁电阵列，以最大化微多普勒频率。与超散射体中针对特定入射角和偏振的常规高阶多极设计不同，本文方法在雷达相关条件下针对旋转叶片联合优化了激励和散射。所得阵列表现出巨量旋转超微多普勒响应，超过偶极极限两个数量级，并将数十赫兹的旋转映射到千赫兹范围。除基础意义外，该映射具有实用价值，因为它将转子微多普勒信号移至远高于慢速运动雷达杂波的位置，从而提升了慢速运动的可探测性。
英文摘要
The motion of a rigid body interacting with a wave leaves spectral signatures, with the Doppler shift as the dominant contribution. Since any motion can be decomposed into translational and rotational components, rotational Doppler provides additional information about the object's dynamics. In the electromagnetic domain, rotating objects generally produce rotational Doppler, or micro-Doppler, signals determined by the symmetry and spatial structure of the scattering process. For objects that are subwavelength or comparable in size to the wavelength, the response is typically dominated by the lowest dipolar scattering channel, so the leading spectral component commonly appears at twice the angular frequency. Here, we introduce the concept of artificially engineered rotational micro-Doppler by designing a compact, strongly scattering structure that operates through a high-order multipolar cascade of resonances, thereby producing a giant enhancement. Magneto-electric arrays composed of strongly coupled electric and magnetic resonators are optimized in the GHz range using a covariance matrix adaptation genetic algorithm to maximize the micro-Doppler frequency. Unlike conventional higher-order multipole designs used in superscatterers for a specific angle of incidence and polarization, our approach jointly optimizes excitation and scattering under radar-relevant conditions for a rotating blade. The resulting arrays exhibit a giant rotational meta-micro-Doppler response, exceeding the dipolar limit by two orders of magnitude and mapping rotations of tens of hertz into the kilohertz range. Beyond its fundamental significance, this mapping has practical value because it shifts rotor micro-Doppler signatures well above slow-moving radar clutter, thereby improving the detectability of slow motion.
