A planar UWB MIMO antenna with gain enhancement and isolation improvement for the 5G Mobile platform

A planar ultra‐wide band (UWB) multi‐input multi‐output (MIMO) antenna with gain enhancement and isolation improvement for the 5G mobile platform is proposed. The proposed antenna consists of two planar UWB low‐band antenna elements: a compact multi‐loop antenna and a ground‐slotted planar inverted F antenna (PIFA) located on the opposite side of the rectangular ground plane. These two antennas satisfy the 10‐dB return loss bandwidth from 2.90 to 6.94 GHz for multi‐loop antenna and from 2.79 to 7.23 GHz for slotted PIFA antenna, respectively. A high isolation level of greater than 20 dB is realized without applying any additional decoupling structures. The realized gains are larger than 2.9 dBi. The experimental and simulated results of the proposed antenna are in good agreement with each other.