The evolution of wireless networks is driving new paradigms for consideration in upcoming generations. To this end, the 6G anticipates the development of several data-rate-hungry applications, in addition to a forecast growth in sensing-centric applications. Such an evolution, however, is unbalanced on the other side by the accentuated scarcity of spectrum, which opens up urgent needs to develop spectrum-efficient communication and sensing techniques. Due to the inability of the traditional multi-antenna schemes to enhance a wireless channel quality, increasing interest has been paid to wireless channel-altering schemes, such as reconfigurable intelligent surfaces and movable antennas. Recently, a new technique in this category, called pinching antennas (PAs), was introduced and tested. PA systems (PASS) are based on extending the reach of a base station by connecting its radio-frequency chains to long waveguides, on which one or many radiating antennas are pinched at custom positions of interest. Thus, such a technique can provide a means of overcoming several unfavorable channel conditions, such as the absence of a line-of-sight and increased free-space path loss. Importantly, such a channel-tuning feature can provide notable enhancements in terms of sensing, network coverage, data rate, and resilience against eavesdropping. In this work, we provide a comprehensive review of research on PASS, designed to meet various system design objectives, such as network coverage and data rate, information-theoretically secure transmission, sensing, integrated sensing and communication, and energy efficiency. A categorization of the surveyed work is established by comparing the various PASS schemes presented. Several takeaways are illustrated on the proposed schemes' potential and limitations, along with several directions forward discussed, in terms of future deployment and implementation.

翻译：无线网络的演进正推动着新一代通信范式的思考。为此，6G除预见了若干高数据速率应用外，还预测了以感知为中心的应用增长。然而，这种演进在另一方面却面临频谱资源日益稀缺的不平衡，从而催生了开发频谱高效通信与感知技术的迫切需求。由于传统多天线方案无法提升无线信道质量，可重构智能表面与可移动天线等无线信道调控方案日益受到关注。近期，该领域一项名为"钳形天线（PAs）"的新技术被提出并测试。钳形天线系统（PASS）通过将基站的射频链连接至长波导，并在波导上按需在特定位置夹持一个或多个辐射天线，从而扩展基站覆盖范围。该技术可有效克服多种不利信道条件，例如视距缺失和自由空间路径损耗增加。尤为重要的是，这种信道调谐能力可在感知、网络覆盖、数据速率及抗窃听鲁棒性方面实现显著提升。本文对PASS研究进行了全面综述，旨在满足多种系统设计目标，如网络覆盖与数据速率、信息论安全传输、感知、通感一体化及能量效率。通过比较现有各类PASS方案，建立了研究工作分类体系。本文揭示了所提方案的潜力与局限性，并从未来部署与实施角度讨论了若干发展方向。