Pinching-antenna systems have emerged as a novel and transformative flexible-antenna architecture for next-generation wireless networks. They offer unprecedented flexibility and spatial reconfigurability by enabling dynamic positioning and activation of radiating elements along a signal-guiding medium (e.g., dielectric waveguides), which is not possible with conventional fixed antenna systems. In this paper, we introduce the concept of generalized pinching antenna systems, which retain the core principle of creating localized radiation points on demand, but can be physically realized in a variety of settings. These include implementations based on dielectric waveguides, leaky coaxial cables, surface-wave guiding structures, and other types of media, employing different feeding methods and activation mechanisms (e.g., mechanical, electronic, or hybrid). Despite differences in their physical realizations, they all share the same inherent ability to form, reposition, or deactivate radiation sites as needed, enabling user-centric and dynamic coverage. We first describe the underlying physical mechanisms of representative generalized pinching-antenna realizations and their associated wireless channel models, highlighting their unique propagation and reconfigurability characteristics compared with conventional antennas. Then, we review several representative pinching-antenna system architectures, ranging from single- to multiple-waveguide configurations, and discuss advanced design strategies tailored to these flexible deployments. Furthermore, we examine their integration with emerging wireless technologies to enable synergistic, user-centric solutions. Finally, we identify key open research challenges and outline future directions, charting a pathway toward the practical deployment of generalized pinching antennas in next-generation wireless networks.

翻译：夹持天线系统作为一种新颖且具有变革性的柔性天线架构，已为下一代无线网络所采用。通过实现在信号引导介质（如介质波导）上动态定位和激活辐射单元，该系统提供了前所未有的灵活性与空间可重构性，这是传统固定天线系统无法实现的。本文介绍了广义夹持天线系统的概念，其保留了按需创建局部辐射点的核心原理，但可在多种物理环境中实现。这包括基于介质波导、泄漏同轴电缆、表面波导结构及其他类型介质的实施方案，采用不同的馈电方法与激活机制（如机械式、电子式或混合式）。尽管物理实现方式各异，它们均具备根据需要形成、重定位或停用辐射点的固有能力，从而实现以用户为中心的动态覆盖。我们首先阐述了典型广义夹持天线实现的基础物理机制及其对应的无线信道模型，重点分析了其相较于传统天线独特的传播特性与可重构特性。随后，我们回顾了从单波导到多波导配置的若干代表性夹持天线系统架构，并讨论了针对这些柔性部署的先进设计策略。此外，我们探讨了其与新兴无线技术的融合，以实现协同的、以用户为中心的解决方案。最后，我们指出了当前面临的关键开放性研究挑战，并展望了未来发展方向，为广义夹持天线在下一代无线网络中的实际部署规划了技术路线。