28/38 GHz dual-band MIMO antenna with wideband and high gain properties for 5G applications

In this paper, a novel high gain 4-element dual-band multiple-input multiple-output (MIMO) antenna is proposed for fifth generation (5G) wireless applications. A crescent shape is created initially from a circular structure and then the proposed antenna is formed by using slots and Defected Ground Structures (DGS) to set resonances at the desired frequencies. The proposed MIMO antenna operates both at 28 GHz and 38 GHz frequencies. In addition, the MIMO antenna has 3.05 GHz and 2.41 GHz bandwidth at those frequencies, respectively. The antenna elements are orthogonally placed to each other as a design concept to enhance the isolation between the elements up to 30 dB. Moreover, the MIMO antenna has maximum measured gains of 8.14 dB and 8.04 dB at 28 GHz and 38 GHz, respectively. The antenna size achieves compactness with the total size of 60 x 60 x 0.508 mm3. The designed MIMO antenna is also evaluated in terms of important MIMO parameters such as diversity gain (DG), envelope correlation coefficient (ECC), mean effective gain (MEG), and channel capacity loss (CCL). The proposed antenna is a great candidate for modern 5G applications that require both wideband and high gain properties with its MIMO antenna parameters of DG, ECC , MEG and CCL.