Millimeter-Wave Dual-Band MIMO Antennas for 5G Wireless Applications

This paper suggests a dual-band 28/38 GHz four-element MIMO array based on dual-mode planar monopole antennas for 5G wireless applications. The design structure contains four planar monopole antennas; located at the corners on a 20 × 20-mm 2 size Rogers RO4003 substrate with a dielectric constant of 3.55. The proposed planar monopole antenna has the shape of a crescent. In order to achieve the desired behavior and perfor mance, we engraved two rectangular slots on both sides and also added a notch at the bottom. In addition, we used a partial ground plane to enhance the isolation. Significant isolation (> − 23 dB) is achieved between antenna elements by employing spatial and polarization diversity techniques. To validate the design concept, a prototype of the four-element MIMO array is designed, fabricated, and measured. The experimental results show that the proposed antenna can cover the 27.25–29 GHz and 34.5–41 GHz bands with good isolation and high efficiency. Furthermore, the radiation pattern, the realized gain, and the channel capacity are also studied. According to the reached results, the proposed MIMO antenna may be a suitable application-oriented design for 5G MIMO applications at the millimeter-wave range.