AI 中文总结
本文针对流体天线阵列的互耦问题，提出感知互耦的稀疏端口选择框架，通过耦合多端口网络建模优化，提升了主瓣SNR与PSLL，证明设计中应利用互耦而非仅补偿。
AI 中文摘要
流体天线系统通过在限定区域内重新配置天线位置来获取空间自由度，该原理可扩展至波束成形：使用比候选天线位置少得多的射频馈源即可合成成形波束。然而，当候选天线位置密集排列时，电磁互耦会改变终端电压、感应电流与辐射场之间的关系，因此无互耦模型不再能描述硬件特性，可能会激活不合适的端口集合，导致合成方向图失真。本文提出一种感知互耦的框架，该框架将期望的波束幅度转换为与有限孔径兼容的复目标，并将完整天线阵列建模为耦合多端口网络，通过耦合电压-场响应选择激活端口及其源电压。未激活的候选端口仍作为网络的一部分并承载感应电流，所有对比设计均在相同源电压预算下通过同一电磁模型进行评估。数值结果表明，感知互耦的设计相比无互耦选择和固定阵列，可同时提升平均主瓣信噪比（SNR）和峰值旁瓣电平（PSLL），证明应在设计本身中利用互耦，而非仅在最终评估中对其进行补偿。
英文摘要
Fluid antenna systems obtain spatial degrees of freedom by reconfiguring antenna positions within a confined region, a principle that extends to beamforming: shaped beams can be synthesized using far fewer radio-frequency feeds than candidate antenna positions. When the candidates are densely arranged, however, electromagnetic mutual coupling changes the relationship among terminal voltages, induced currents, and radiated fields, so an uncoupled model no longer describes the hardware and may activate an unsuitable set of ports, distorting the synthesized pattern. This paper develops a mutual-coupling-aware framework that converts the desired beam amplitude into a finite-aperture-compatible complex target and models the complete antenna lattice as a coupled multiport network, selecting the active ports and their source voltages through the coupled voltage-to-field response. Inactive candidate ports remain part of the network and carry induced currents, and every compared design is evaluated through the same electromagnetic model under the same source-voltage budget. Numerical results show that the mutual-coupling-aware design improves both the average mainlobe signal-to-noise ratio (SNR) and the peak sidelobe level (PSLL) over coupling-unaware selection and a fixed array, demonstrating that mutual coupling should be exploited in the design itself rather than compensated only in the final evaluation.
