Movable antennas (MAs) have emerged as a promising technology for wireless sensing by reconfiguring antenna positions to exploit additional spatial degrees of freedom (DoFs). This paper investigates a robust movable antenna placement strategy for near-field wireless sensing to minimize the worst-case squared position error bound (SPEB). By temporarily relaxing the minimum inter-element spacing constraint, we first establish the optimality of centro-symmetric antenna position distribution, which simplifies the identification of the worst-case source, locating it at the array broadside on the Rayleigh boundary. Moreover, by leveraging moment-based analysis with the Richter-Tchakaloff theorem, we derive a closed-form optimal solution with three points supported on the center and two edges of the array. Guided by this structural insight, we finally develop an efficient three-point discrete deployment strategy to ensure the minimum inter-element spacing. Simulations demonstrate that the proposed design consistently outperforms conventional fixed antenna arrays and matches the exhaustive search benchmark at negligible computational complexity.

翻译：可移动天线（MAs）通过重新配置天线位置以利用额外的空间自由度（DoFs），已成为一种极具前景的无线传感技术。本文研究了一种用于近场无线传感的鲁棒可移动天线部署策略，旨在最小化最坏情况下的平方位置误差界（SPEB）。通过暂时放宽最小阵元间距约束，我们首先建立了中心对称天线位置分布的最优性，这简化了最坏情况信源的识别，将其定位在阵列法线方向上的瑞利边界处。此外，通过利用基于矩的分析与Richter-Tchakaloff定理，我们推导出了一个具有闭式解的最优方案，其支撑点位于阵列的中心和两个边缘。基于这一结构洞见的指导，我们最终开发了一种高效的三点离散部署策略，以确保最小阵元间距。仿真结果表明，所提出的设计始终优于传统的固定天线阵列，并且以可忽略的计算复杂度达到了穷举搜索基准的性能。