A Novel High Isolation 4-Port Compact MIMO Antenna with DGS for 5G Applications

Abstract

This paper presents the design and realization of a simple and low-profile, 4-port Multiple-Input-Multiple-Output (MIMO) antenna operating in the mm-wave band supporting 5G communication technologies. As part of the design methodology, the initial stage involved the development of a conventional monopole patch antenna optimized for operation at 26 GHz, which is matched to 50 Ω stepped feed line. Afterward, a square-shaped Defected Ground Structure (DGS) with semi-circles slots on the edges is placed on the ground to improve the isolation and the circular and rectangular slots are incorporated as DGS to optimize the antenna impedance bandwidth. Etching semi-circular shaped slots on the ground plane achieved more then 34.2 dB isolation in the 26 GHz operating band. In addition, an arrangement of four symmetrical radiating elements is positioned orthogonally to minimize the antenna’s physical size and to improve the isolation. The proposed MIMO antenna overall dimension is 25 × 25 mm2, which is printed on Rogers 5880 substrate with a width of 0.787 mm and εr = 2.2. The proposed antenna covers the 5G mm-wave band with a 10 dB bandwidth ranging from 25.28 - 28.02 GHz, whereas the maximum gain attained for the purposed structure is 8.72 dBi. Moreover, the proposed design, simulated and measured with advantages such as high isolation, low ECC, simple and compact design, is a good candidate for usage areas such as smart devices, mobile phones, and sensors in 5G applications.