Liquid-Based Reconfigurable $4\mathrm{x}4$ Butler Matrix for Enhanced Spatial Coverage
Sohail Iqbal, Muhammad Usman Khan, Wasif Tanveer Khan, Rifaqat Hussain, James Floyd Kelly, Akram Alomainy · 2024
In this paper, a novel design of liquid based reconfigurable Butler matrix is proposed. Based on proposed concept,$4\mathrm{x}4$butler matrix along with 4-element patch antenna is designed at 2.0 GHz frequency. Re-configurability in design is achieved by using liquid (water in this case) with the help of Polylactic Acid (PLA) structure using loading component method. 15 Liquid channels (having six sets of 5 channels each on both upper and lower sides) were filled in various combinations to vary progressive phase shift of output ports of Butler Matrix, by doing so, enhanced spatial coverage over the scale of$\pm 90^{\circ}$is achieved while maintaining a -10dB impedance bandwidth from 1.8 GHz to 2.2 GHz (400MHz). In contrast to other re-configurability approaches, the proposed approach offers a low profile, low cost, and compact size solution, making it highly suitable for radar and wireless communication and other tune-able devices applications in S-band.