A Side-Edge Frame Printed Eight-Element Antenna Array for Quad-Band MIMO Operations in the 5G Smartphone

In this article, an eight-element antenna array operating in the 2.6/3.5/4.9/5.2-GHz quad-band for 8×8 multi- input multi-output (MIMO) operation in the 5G (fifth-generation) smartphone is presented. The proposed antenna array is formed by eight identical antenna elements printed on the inner surface of the side-edge frame of the smartphone casing. Simulated results show that the impedance bandwidth of each antenna element can fully cover quad-band of 2496-2690/3400-3600/4800- 5000/5150-5350 MHz for reflection coefficient less than -6 dB (3:1 VSWR). Besides, desired gain, 3-D radiation patterns, total efficiency (more than 40%) are simulated and presented. In addition, good ECC (Envelope Correlation Coefficient) of less than 0.2 for any two antenna elements and acceptable isolation (better than 10.8-dB) are also obtained.