High-Performance Eight-Port MIMO Antenna for Sub-6 GHz 5G Smartphones

This paper presents a compact multiple-input multiple-output (MIMO) antenna design for 5G cellular applications.The array consists of four identical compact antenna elements capable of providing extensive radiation coverage and diverse functionalities.Each element utilizes a dual-polarized diamond-ring slot resonator, fed by two microstrip feed lines, operating at 3.4 GHz, making it ideal for the 5G band.This paper emphasizes the importance of achieving desirable isolation between adjacent elements and demonstrates simple but effective decoupling techniques.To achieve this, we incorporate parasitic elements, neutralization lines (NL), a defected ground plane, and arrange the radiating elements at varying orientations relative to each other.This antenna provides a bandwidth of 400 MHz (3.15-3.7 GHz), delivering high-gain patterns with minimal ECC/TARC.Experimental measurements confirm the reliability of the MIMO array by implementing it on a smartphone board, which closely matches the expected performance characteristics.