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, four-port multiple-input-multiple-output (MIMO) antenna operating in a 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 was matched to a 50 Ω stepped feed line. Afterward, a square-shaped defected ground structure (DGS) with semi-circle slots on the edges was placed on the ground to improve the isolation, and the circular and rectangular slots were incorporated as DGSs to optimize the antenna impedance bandwidth. Etching semi-circular-shaped slots on the ground plane achieved more than 34.2 dB isolation in the 26 GHz operating band. In addition, an arrangement of four symmetrical radiating elements was positioned orthogonally to minimize the antenna’s physical size and improve the isolation. The proposed MIMO antenna’s overall dimension was 25 × 25 mm2, which was printed on a Rogers 5880 substrate at a width of 0.787 mm and εr = 2.2. The proposed antenna covered the 5G mm-wave band with a 10 dB bandwidth ranging from 25.28–28.02 GHz, whereas the maximum gain attained for the proposed structure was 8.72 dBi. Additionally, the implementation of these slots effectively mitigated mutual coupling, resulting in reduced envelope correlation coefficient (ECC) values. Furthermore, other MIMO performance metrics, including channel capacity loss (CCL), mean effective gain (MEG), and diversity gain (DG), were analyzed for the proposed structure. The obtained results indicate its suitability for various usage areas, such as smart devices, mobile phones, and sensors in 5G applications.

Design and Optimization of a Compact Super-Wideband MIMO Antenna with High Isolation and Gain for 5G Applications

“…The DG, which shows the degree of transmission power reduction, constitutes an important performance metric. It is computed from the ECC as follows [33]…”

“…The DG, which shows the degree of transmission power reduction, constitutes an important performance metric. It is computed from the ECC as follows [33] In general, higher DG values indicate better MIMO performance. Figure 12b presents the simulated and measured DG results, which show high DG values across the entire bandwidth, approaching the standard of 10 dB.…”

Design of High-Gain and Low-Mutual-Coupling Multiple-Input–Multiple-Output Antennas Based on PRS for 28 GHz Applications

“…While this proposed antenna benefits from its compact size, it still faces various challenges, including low gain, limited bandwidth, and the absence of a common ground plane in its design, rendering it less suitable for practical applications. Similarly, [13] introduces an MIMO antenna based on a dielectric resonator. This design achieves a mutual coupling of >−24 dB within the frequency range of 25.2~28 GHz.…”