Dual-band eight-element antenna array for 5G smartphone applications

In this work, an eight-antenna array operating in 3.5 GHz band (3300-3700 MHz) and 5 GHz band (4600-5300 MHz) for 5G smartphone applications is presented. The eight-antenna array formed by four dual-antenna units is placed along the two long frames of the smartphone symmetrically. Each dual-antenna unit consists of two natural-high-isolation antennas with a spacing of only 3 mm, one is a folded loop antenna and the other is an opened slot antenna. Therefore, without any decoupling structure, isolation obtained is at least 11 dB. The efficiency of all antennas is higher than 52% in the operating bands, and the envelope correlation coefficient (ECC) values do not exceed 0.17 between all elements.