Unconventional Array for 5G Scenario: Irregular Clustering Antenna Design and Implementation

Current trends for mmWave (millimeter Wave) MIMO communications exploit large antenna arrays with hundreds of radiating elements, which provide highly-directive beams allowing spectral reuse through spatial diversity. Unconventional arrays are proposed for the design of base station systems for 5G applications, with the goal to simplify the required beamforming architecture with respect to standard fully-populated arrangements. This article presents an overview of some design activities, covering two different unconventional array solutions, showing implementation challenges as well as the latest achievements on this field.