Uma investigação sobre o emprego de ressonadores líquidos em antenas patch retangulares

Abstract

This study investigates, through numerical simulations, the influence of resonators using certain liquids (distilled water, deionized water, saline water, and glycerin) and some

geometric solid shapes (rectangular parallelepiped, convex hemisphere, concave hemi- sphere, convex cylinder cap, and concave cylinder cap) on the performance of rectangular

patch antennas, which utilize FR-4, Rogers RO4725JXR, and RT-Duroid 6010LM sub- strates. The results of the numerical simulations show that the use of liquid resonators

can significantly alter the performance of rectangular patch antennas in terms of elec- tromagnetic performance parameters obtained from radiation and polar diagrams. For

example, liquid resonators have a greater impact on rectangular patch antennas using low-quality substrates (FR-4) compared to those using higher-quality substrates (Rogers

RO4725JXR and RT-Duroid 6010LM). The numerical results also show that the geomet- ric shape adopted by the resonator is also relevant in determining the liquid resonator’s

impact. Finally, the numerical results indicate that liquid resonators based on deionized

and distilled water exhibit the best performance, while sea water presents the worst re- sults due to its high conductivity. The use of glycerin in liquid resonators showed good

results compared to saline water, despite presenting impedance mismatch in some cases. The presented analyses indicate that the use of liquid resonators can considerably alter the behavior of a rectangular patch antenna and, consequently, significant improvements are observed when the quality of the employed substrate is low.