An Eleven-State Pixel-Reconfigurable Beamforming Network for Fluid Antenna Systems Across 0.5λ
Jichen ZHANG, Junhui Rao, Zhaoyang Ming, Yijun Chen, Alikhan Umirbayev, Frankie Chiu, Ross Murch · Rare & Special e-Zone (The Hong Kong University of Science and Technology) · 2026
In this paper, a novel pixel-reconfigurable beamforming network (PRBFN) for Fluid Antenna Systems (FASs), referred to as a PRBFN-FAS, is proposed to overcome the switching speed limitations inherent in conventional mechanically-reconfigurable FAS. Building on the insight that switching between reconfigurable radiation patterns is functionally equivalent to changing the physical antenna position, our novel approach employs beamforming, by utilizing a PRBFN connected to a multi-port antenna, to realize FAS. By optimizing the beamforming currents at the PRBFN outputs, the desired correlation characteristics across all radiation patterns can be achieved. To validate the concept, a PRBFN-FAS prototype with N=11 reconfigurable states is designed and fabricated at 2.6GHz, emulating an FAS with N=11 port positions uniformly distributed across W=0.5 wavelengths. Measurement shows good agreement with Bessel spatial correlation in Clarke's model across all states over a 7% bandwidth. Communication system experiments verify the superior performance of the PRBFN-FAS.