Compact Configured 5G Dual-Band MIMO Loop Antenna System

Abstract

This paper presents a compact configured 5G dual-band MIMO loop antenna system for laptop computers. The antenna system consists of two identical 95 × 2 mm2 four-antenna units that are arranged on the top edge of the display ground plane and are 10 mm away from the left and right sides. The four-antenna unit, each being a two-dimensional loop antenna of the same structure and size, are constructed on the on a 0.4 mm-thick FR4 substrate. The loop antenna with only 23 × 2 mm2 size 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 cover 5G dual-band operation at 3300–3600 MHz and 4800–5000 MHz. The measured isolation between eight antennas is all better than 15 dB, the measured antenna efficiency is between 35% and 62%, and the measured envelop correlation coefficient ECC calculated from the electric-field radiation pattern is all less than 0.2. This compactly configured eight-antenna system is only 2 mm high in profile, making it ideal for use in 5G laptops with a high screen-to-body ratio.