SRR and DGS-Based Highly Isolated Four-Port MIMO Antenna for Mid-5G Band and High-5G Band

This manuscript proposed a compact four-port multiple input multiple output (MIMO) antenna based on four split-ring resonators (SRR) at the top and a defected ground structure (DGS) at the bottom of the substrate for 5G communication. SRRs are used to resonate at 4 GHz frequency in mid-5G band. A slot of “ + ” symbol is cut at the bottom (DGS) to enlarge the bandwidth. The proposed antenna also achieved a high-5G frequency band (26.8–29.8 GHz) (n257/n258 band) by four square-shaped ring slots at the ground plane. It further enhances the bandwidth in mid-5G band (2.9–6 GHz) (n74/n75/n76/n77/n78 band) and helps to achieve a high degree of isolation between each radiating element (over 40 dB) at both the 5G bands. The size of the proposed MIMO antenna is 60 mm × 60 mm × 1.6 mm. It achieves a maximum gain of 4.59 dB, 4.32 dB at the mid-5G and high-5G band, respectively. The maximum radiation efficiencies achieved are 89%, 81% at the mid-5G and high-5G band, respectively. The diversity functionality of the antenna is also outstanding as the value of ECC is 0.01–0.42, DG is 9.6–10 dB, and TARC is less than − 10 dB measured in both the bands. The entire performance of the proposed antenna is practically verified, discussed and presented.