Reconfigurable Water-Based End-Fire Antenna with Directional Radiation Patterns
Shun Lu, Guowen Ding, Xinyao Luo, Shen‐Yun Wang · 2024
This paper proposes a water-based end-fire antenna designed to achieve an end-fire radiation pattern and offer pattern reconfigurability. The design employs a monopole as the resonant element and introduces a parasitic unit to reflect energy towards the edge, thereby achieving an end-fire effect and enabling beam steering at 30° intervals. The antenna leverages the unique properties of water, including its fluidity, transparency, and reconfigurability. The operating frequency range spans from 3.16 to $4.74 \mathrm{GHz}\left(\mathrm{S}_{11}{\lt}-10 \mathrm{~dB}\right.$), with a relative bandwidth of $\mathbf{4 0 \%}$. Injecting pure water into six adjacent plastic tubes generates 12 distinct operational states, with a maximum gain of 6.372 dB and a stable end-fire radiation mode. The antenna is compact in size and utilizes a singleport coaxial feed mechanism, ensuring simplicity and efficiency.