Wideband Pixel-Based Fluid Antenna System: An Antenna Design for Smart City
Baiyang Liu, Tuo Wu, Kai‐Kit Wong, Hang Wong, Kin‐Fai Tong
Abstract
Smart cities demand versatile antenna systems supporting heterogeneous wireless applications across diverse propagation environments. This paper presents a wideband pixel-based fluid antenna system (PB-FAS) designed as a general-purpose antenna solution for smart city infrastructures, addressing fundamental challenges in wideband operation, spatial adaptability, interference mitigation, and scalable deployment. The proposed PB-FAS integrates parasitic elements for enhanced bandwidth (6.0-7.0 GHz) and a compact 6-PIN-diode pixel surface enabling 64 distinct fluid states, achieving optimal cost-performance balance. An integrated FPGA-based control system provides microsecond-level reconfiguration for real-time channel adaptation. We establish a rigorous exact spatial geometry (ESG) channel model capturing state-dependent antenna responses across near-field and far-field regions, providing a unified theoretical foundation for interference mitigation analysis. Comprehensive validation through full-wave electromagnetic simulations, anechoic chamber measurements, and experimental two-source 16-QAM communication tests demonstrates up to 11 dB SINR improvement and 13.2% EVM reduction through hardware-level spatial diversity, confirming the system’s effectiveness as a scalable, cost-effective solution for next-generation smart city wireless infrastructures ranging from IoT sensor networks to high-capacity backhaul links.