Design of a Tri-band Reconfigurable Antenna Using Metamaterials for IoT Applications

Abstract This study investigates using a complementary six double hexagonal split ring resonator with a central rectangle-based metamaterial to develop a frequency-reconfigurable antenna. The antenna is used for wireless communication and is printed on an FR-4 dielectric with dimensions of (30 × 30 × 1.6) mm³, ε r = 4.3, and a tangent loss (tan ( σ )) of 0.025. the antenna is initially designed to operate at three frequencies (2.4, 3.6, and 3.7 GHz). Another frequency was added to the set after adding metamaterial to the substrate. The antenna size has been reduced by 16.67% to get the new dimensions of (25 × 25 × 1.6) mm³. The proposed antenna maintains a voltage standing waves ratio below 1.331 in all resonant frequencies, demonstrating its reliability and efficiency. Additionally, the proposed antenna exhibits a radiation efficiency ranging from 70 to 78.37%. The antenna operates in two modes: Mode 1 at 3.6 and 3.7 GHz, and Mode 2, a double-band mode, at 2.4 and 4.9 GHz. The proposed antenna offers many benefits, including its simple construction, minimal return loss, and frequency switching with the help of a positive intrinsic negative diode (SMP1340-079LF). The Results demonstrate that metamaterials reduce antenna size and increase operating frequencies.