Wideband Millimeter-Wave QMSIW MIMO Antenna Array for 5G Wireless Communication

The substrate-integrated waveguide (SIW) antenna has gained prominence in 5G millimeter-wave communications due to its ease of integration and simple planar structure. To meet the increasing demand for high data rates, wide bandwidth is required. This paper presents a wideband quarter-mode substrate-integrated waveguide (QMSIW) antenna array designed for multiple-input multiple-output (MIMO). Each antenna element consists of two QMSIW resonators with different radii of the arc edges at the top corners, which can be used to modify the resonant frequency of the QMSIW and merge the two resonances, thereby increasing the overall bandwidth. Based on the element design, a compact 1×4 MIMO array with wide impedance bandwidth and low envelope correlation coefficient (ECC) is proposed.