Effective area reduction & surface waves suppression of a novel four-element MIMO antenna exclusively designed for dual band 5G sub 6 GHz (N77/N78 & N79) applications

The current work proposes a novel single and 4-element multiple input multiple output antenna with effective area reduction and surface wave suppression for 5G sub 6 GHz applications. The proposed 4-element antenna system is built with a modified 58 × 58 mm² low cost FR4 material with a dielectric constant of 4.4. Working bands for full substrate MIMO antenna are 2.86–4.07 GHz and 5.32–5.58 GHz, with isolation values of 12 dB. The removal of unwanted substrate from the entire substrate results in high isolation values. The isolation is improved to 17.6 dB after the reduction of substrate material area. Due to the defected substrate the proposed antenna can easily attached to the electronic components and mounted. The proposed 4-element design includes the dual bands 3.15–3.81 GHz (N77/N78) and 4.31–4.75 GHz (N79). The advantages of a defected substrate over a full substrate are effective area reduction and surface wave suppression. In addition, good impedance matching is achieved in sub-6 GHz applications. The efficiency and gain values are simulated, and are greater than 75% and minimum of 3.5 dBi in both the bands respectively. The 3D radiation patterns and 2D patterns are simulated, and the 2D patterns are validated using measured results. The proposed 4-element design’s diversity performance is evaluated using the metrics ECC, DG, CCL, TARC, and MEG. A high degree of agreement can be found between simulated and measured outcomes. Hence, the proposed antenna is well suited for 5G cellular wireless application.