Quad-port octagon slotted high isolation MIMO antenna for GSM1800 to X-band wireless applications

This research article outlines the evolution of an octagon slotted quad port MIMO antenna with enhanced isolation in 1.71–12 GHz band, which includes GSM1800 to X-bands. This MIMO is printed on an FR4 material substrate of area 78 × 78 mm2 (0.343λ0 × 0.343λ0), where λ0 is calculated at lower cut off frequency, and 2 mm (0.009λ0) inter-element separation between the radiators. It has four octagon slotted circular radiating elements placed orthogonally. The isolation of the presented MIMO design is enhanced by the introduction of decoupling networks. The performance characteristics are S11 ≤ – 10 dB in the range 1.32–12.10 GHz, S21 ≤ – 21.94 dB, and S31 ≤ – 20 dB. The peak gain is 6.2 dBi, maximum efficiency is 96%. The diversity characteristics of the proposed design are ECC ≤ 0.03, MEG ratio ≈ 1, TARC ≤  − 10 dB, CCL < 0.35 bps/Hz, and DG ≤ 10. The design is verified and the measured results are consistent with simulated results.