Next-Generation Reconfigurable Antenna Systems for 6G: Challenges, Architectures, and Vision

Reconfigurable antenna systems are a key technology for sixth-generation (6G) networks. They enable dynamic adaptation in frequency, spatial, and polarization domains. This paper presents a unified framework for fluid antennas, pinching antennas, electromagnetically reconfigurable antennas, graphene-based terahertz (THz) antennas, and stretchable or conformal arrays. Physical principles, architectural integration, and control mechanisms are discussed in detail. Representative 6G use cases are examined, including vehicular ultra-reliable low-latency communication (URLLC), THz backhaul in cell-free massive multiple-input multiple-output (CF-mMIMO) networks, satellite–terrestrial integration, and joint communication–sensing (JCAS). Architectural interactions with reconfigurable intelligent surfaces, holographic MIMO, and integrated sensing and communication platforms are outlined, along with their roles in multi-band operation, energy harvesting, and backhaul enhancement. Key implementation challenges are identified in channel modeling, hardware fabrication, control protocols, scalability, and standardization. The paper concludes by identifying potential research directions for advancing reconfigurable antenna technologies within the broader 6G ecosystem.