Meta Fluid Antenna: Architecture Design, Performance Analysis, and Experimental Examination

Fluid antenna systems (FASs) have recently emerged as a promising solution for sixth-generation (6G) ultradense connectivity. These systems utilize dynamic radiating and/or shaping techniques to mitigate interference and improve spectral efficiency without relying on channel state information (CSI). The reported improvements achieved by employing a single dynamically activated radiating position in fluid antenna multiple access (FAMA) are significant. To fully realize the potential of FAMA in multiuser multiplexing, we propose leveraging the unique fast-switching capabilities of a single radio frequency (RF)-chain meta-fluid antenna structure to achieve multiactivation. This allows for a significantly larger set of independent radiating states without requiring additional signal processing. Simulations demonstrate that multiactivation FAMA enables robust multiuser multiplexing with a higher signal-to-interference ratio (SIR) under various Rayleigh-fading environments compared to other single RF-chain technologies. We further show that the SIR can be optimized within a 15μ s timeframe under a multiuser Rayleigh-fading channel, making the proposed scheme highly suitable for fast-changing wireless environments. Verified through the theoretical Jakes' model, full 3-D electromagnetic (EM) simulations, and experimental validation, multiactivation FAMA enables effective CSI-free, multiuser communication, offering a scalable solution for high-capacity wireless networks.