Failure-resilient wideband metal-driven antenna with minimal liquid for reconfigurable system integrity

This paper presents a wideband reconfigurable antenna employing an active feeding element to excite parasitic dielectric elements for pattern reconfiguration with minimal liquid volume. The design utilizes an FR4 substrate with a metallic rod as the active radiator and four diagonally placed liquid containers above a printed circuit board (PCB). The antenna excites a hybrid HEM 11δ mode, achieving a broad impedance bandwidth of 66.6% (3.2–6.2 GHz) and a peak gain of 6.7 dBi at (ϕ = 0°, θ = ± 45°) and (ϕ = 90°, θ = ± 45°). The antenna resonates within the WLAN frequency spectrum, covering the 3.6, 4.9, 5 and 5.9 GHz bands. The radiation pattern is reconfigurable through liquid manipulation, maintaining stable omnidirectional characteristics under liquid failure conditions. Parametric and mathematical analyses validate the interaction between active-metal and passive-liquid DRAs. The fabricated prototype shows excellent agreement with simulations, demonstrating a lightweight, cost-effective, and reliable solution for advanced wireless applications.