Dual-band Massive MIMO Antenna design with enhanced isolation and higher efficiency for 5G Smartphone Application

Abstract

In this work, an F-shaped dual-band 8-component multiple-input multiple-output (MIMO) antenna is proposed for a smartphone application. The antenna setup is made over a 140x70x1mm FR-4 substrate backed by a copper ground plane. The operating frequency range of the antenna units is 3.4 GHz - 3.6 GHz and 5.3GHz – 5.7GHz. The antenna units are fed by 50-ohms Microstrip patch lines. The overall thickness of the antenna setup is 6mm. All the antenna units are placed on the long edges of the frame of the smartphone in a face-to-face and back-to-back configuration. Shorter edges can be utilized for other antennas. To maintain lower mutual coupling, defected ground structure (DGS) has been used between two closely placed antenna components. Antenna unit's optimal positions are found using characteristic mode analysis (CMA). The bandwidth (<−6dB) is 280 MHz and 1400 MHz, in 3.5 GHz frequency band and 5.5 GHz frequency band respectively. The envelop correlation coefficient is less than 0.015 in both operating bands between any two antennas. The total efficiency in the lower band (3.4GHz – 3.6GHz) is above 60% and in the higher band (5.3GHz -5.7 GHz) is above 75%.