Compact 8-Port Low-Profile Antenna Array for 5G Mobile Phones

A compact eight-element frame antenna array covering the 5G n79 frequency band (4.4-5.0 GHz) has been proposed in this paper. Considering the demands in the application of 5G ultrathin smartphones, the antenna unit has been miniaturized and designed with a low profile. Each antenna unit occupies a distance of 11.1 mm on the long edge, and the profile height of each unit is only 3 mm. The antenna array consists of 8 identical monopole antennas. By loading an inverted E-shaped slot on the ground plane and arranging the positions of the antenna units reasonably without the need for a decoupling structure, the antenna can achieve a low profile and compact design. Simultaneously, it can achieve excellent isolation and cover the entire n79 frequency band. The processed eight-element antenna array has a -6 dB bandwidth ranging from 4.38 to 5.19 GHz. The isolation between all antennas is better than -13.9 dB. The total efficiency is between 48.66% and 90.57%, with an average efficiency of 68.6%. The ECC (envelope correlation coefficient) is less than 0.066. The antenna array is characterized by its small size, low profile, simple structure, easy manufacturing, and excellent radiation performance. It holds significant application value in the design of MIMO antennas for 5G ultrathin smartphones.