A Survey of Pinching-Antenna Systems (PASS)

TL;DR

This survey comprehensively reviews the principles, designs, applications, and performance analysis of pinching-antenna systems (PASS), highlighting their potential for flexible reconfiguration and stable links in next-generation wireless networks.

Contribution

It provides a detailed overview of PASS architectures, recent design innovations, performance insights, and discusses open challenges for future research.

Findings

PASS enables large-scale antenna reconfiguration.

PASS improves line-of-sight link stability and mitigates blockage.

Performance analysis shows significant gains in wireless sensing and communication.

Abstract

The pinching-antenna system (PASS), recently proposed as a flexible-antenna technology, has been regarded as a promising solution for several challenges in next-generation wireless networks. It provides large-scale antenna reconfiguration, establishes stable line-of-sight links, mitigates signal blockage, and exploits near-field advantages through its distinctive architecture. This article aims to present a comprehensive overview of the state of the art in PASS. The fundamental principles of PASS are first discussed, including its hardware architecture, circuit and physical models, and signal models. Several emerging PASS designs, such as segmented PASS (S-PASS), center-fed PASS (C-PASS), and multi-mode PASS (M-PASS), are subsequently introduced, and their design features are discussed. In addition, the properties and promising applications of PASS for wireless sensing are reviewed. On this basis, recent progress in the performance analysis of PASS for both communications and sensing is surveyed, and the performance gains achieved by PASS are highlighted. Existing research contributions in optimization and machine learning are also summarized, with the practical challenges of beamforming and resource allocation being identified in relation to the unique transmission structure and propagation characteristics of PASS. Finally, several variants of PASS are presented, and key implementation challenges that remain open for future study are discussed.