3D MIMOAntenna Designs

Abstract

Multiple‐input multiple‐output (MIMO) technology has been a key driver in the development of fourth‐generation wireless systems and will continue to be utilized in the upcoming fifth‐generation one. MIMO was an excellent technology to make use of multipath effects and enhance the system capacity dramatically. A new technology that is based on MIMO that utilizes large amounts of antennas at the base‐station side to simultaneously send dedicated beams and create dedicated channels for various users has been identified and will be deployed with fifth‐generation systems to enhance the channel capacity even more. This technology is called massive‐MIMO (MaMI). The majority of works that addressed MaMI focused on one dimensional (azimuthal) beam steering. Adding the second dimension (elevation) to the original MaMI systems has been denoted as three‐dimensional MIMO (3D‐MIMO) since the beams will cover the 3D space in front of the MaMI array, thus enhancing coverage, reducing interference and enhancing capacity. This article focuses on 3D‐MIMO antenna array systems, their performance metrics and some examples of actual implementations at microwave and mm‐wave bands.