Compact Multi-Input Multi-Output Loop Antenna System for 5G Laptops

This paper presents a compact configured 5G dual-band multi-input multi-output (MIMO) loop antenna system for laptop computers. The antenna system is consisted of two identical 95 × 2 mm
²
four-antenna units that are allocated on the top edge of the display ground plane and are 10 mm away from both the left and right sides. Each four-antenna unit is a two-dimensional loop antenna of the same structure and size. The loop antenna is composed of a T-shaped feed-in section and a double short-circuit loop. In addition, the four loop antennas are arranged in the same direction and side by side with only 1 mm space to form a high-isolation four-antenna unit. The two sets of four-antenna units can be used in 5G dual-bands of 3,300-3,600 MHz and 4,800-5,000 MHz. The measured isolation results between eight antennas were all better than 15 dB while the measured antenna efficiencies were between 35% and 65%, and the measured envelope correlation coefficient (ECC) calculated from the electric-field radiation pattern were all less than 0.2.