Miniature MIMO Antennas for 5G Mobile Terminals

In this paper, we present the design and the measurement of a miniature MIMO dual-band (2.6/3.6 GHz) antenna array for future 5G handsets. The antenna element has a compact area with size of 10.5×14.5 mm
²
. The proposed antenna array elements are symmetrically placed along the long edges of the smartphone, and they are composed of four same antenna types. Two antennas of the same kind are then closely positioned on the same 120×50 mm2 Printed Circuit Board (PCB). The initial proposed handset-system is composed of U-Shape structure and a connected meandered monopole. Both simulated and measured results are shown to illustrate the MIMO capabilities of the proposed structures. These results show that the presented structure operate in dual-band at 2.5-2.7 GHz and 3.4-3.8 GHz, which has a bandwidth of 200 MHz and 400 MHz respectively for reflection coefficient less than -6dB. The port isolation is more than 11.5 dB across the whole band of interest without using any decoupling network for two antenna structures. The antenna is fabricated using FR4 substrate with relative permittivity of 4.4 and pert tangent of 0.02.