Broadband L-Probe-Fed Pixel-Based Reconfigurable Antenna for High-Speed Fluid Antenna Systems

In this paper, we propose a broadband L-probe-fed pixel-based reconfigurable antenna (PRA) that can be applied to Fluid Antenna Systems (FASs) with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu$</tex> s fast switching speeds, and we refer to this PRA as a PRA-FAS. The FAS concept can be used to enhance wireless system performance, and PRAFAS has been demonstrated as one of the only FAS antenna designs that can achieve the required packet-level FAS switching speeds. In this proposed PRA-FAS design, we employ an Lshaped probe for feeding to address the limited bandwidth of previous PRA-FAS designs when there are a large number of reconfigurable states. Combined with optimized reconfigurable pixel connections, capacitive coupling is generated, thereby extending the bandwidth. Our proposed L-probe-fed PRA-FAS operates at 2.4 GHz and features 12 reconfigurable states, with a bandwidth of 8.3 %, and equivalent to FAS with 12 ports across <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.5 \lambda$</tex> space. Simulation and measurement results indicate that the 12 states of the designed PRA-FAS within the bandwidth generally meet the pattern correlation requirements of the approximate Bessel relationship raised by FAS.