Angular sensing capability is realized using highly reconfigurable pixel antenna (HRPA) with joint radiating aperture and feeding ports reconfiguration. Pixel antennas represent a general class of reconfigurable antenna designs in which the radiating surface, regardless of its shape or size, is divided into sub-wavelength elements called pixels. Each pixel is connected to its neighboring elements through radio frequency switches. By controlling pixel connections, the pixel antenna topology can be flexibly adjusted so that the resulting radiation pattern can be reconfigured. However, conventional pixel antennas have only a single, fixed-position feeding port, which is not efficient for angular sensing. Therefore, in this work, we further extend the reconfigurability of pixel antennas by introducing the HRPA, which enables both geometry control of the pixel antenna and switching of its feeding ports. The model of the proposed HRPA, including both circuit and radiation parameters, is derived. A codebook is then defined, consisting of pixel connection states and feeding port positions for each sensing area. Based on this codebook, an efficient optimization approach is developed to minimize the Cram\acute{\mathrm{\mathbf{e}}}r-Rao lower bound (CRLB) and obtain the optimal HRPA geometries for angular sensing within a given area. Numerical results show that the HRPA reduces the angle estimation error by more than 50% across the full three-dimensional sphere when compared with a conventional uniform planar array of the same size. This demonstrates the effectiveness of the proposed approach and highlights the potential of HRPA for integrated sensing and communication systems.

翻译：角度感知能力通过具有联合辐射孔径与馈电端口重构功能的高可重构像素天线实现。像素天线代表了一类通用的可重构天线设计，其辐射表面（无论形状或尺寸）被划分为称为像素的亚波长单元。每个像素通过射频开关与其相邻单元连接。通过控制像素连接，可灵活调整像素天线的拓扑结构，从而实现辐射方向图的重构。然而，传统像素天线仅具有单一固定位置的馈电端口，这对于角度感知并不高效。因此，本研究通过引入高可重构像素天线进一步扩展了像素天线的可重构性，该天线同时支持像素天线的几何结构控制与馈电端口切换。文中推导了所提高可重构像素天线的模型，涵盖电路参数与辐射参数。随后定义了一个码本，其中包含每个感知区域对应的像素连接状态与馈电端口位置。基于该码本，开发了一种高效的优化方法以最小化克拉美-罗下界，并在给定区域内获得用于角度感知的最优高可重构像素天线几何构型。数值结果表明，在完整三维球面范围内，与相同尺寸的传统均匀平面阵列相比，高可重构像素天线将角度估计误差降低了50%以上。这证明了所提方法的有效性，并凸显了高可重构像素天线在集成感知与通信系统中的潜力。