MIMO antenna for 5G applications A quad-element multiple-input multiple-output (MIMO) antenna operating in 3.5 GHz (3.4GHz-3.6GHz) and 4.9GHz (4.8GHz-4.96GHz) frequency bands for the fifth-generation (5G) smartphone applications is presented. Each single radiating element consists of an L-shaped strip and a modified C-shaped strip. To keep enough space for second-, third-and fourth-generation (2G/3G/4G) antennas in a limited space, four antenna elements are printed respectively at four corners of a system board. The total size of the proposed antenna is only 145×75×5mm3. The design steps and the analysis of key parameters of an individual antenna element are derived to demonstrate the design methodology of the proposed antenna. The measured total radiation efficiency is better than 60% at both the operating frequency bands. The measured isolation is better than 16 dB and the calculated envelope correlation coefficient (ECC) is smaller than 0.02. The measured results demonstrate that the proposed MIMO antenna is a good alternative for sub-6 GHz 5G smartphone applications.