A phased array antenna may include a substrate and a plurality of controllable phased array antenna elements carried thereby, a central controller for generating a mode selection signal and beam control signals, and at least one multi-mode element controller connected to at least one of the controllable phased array antenna elements and the central controller. The at least one multi-mode element controller may be operable in a desired operating mode from among a plurality of operating modes based upon the mode selection signal from the central controller. Furthermore, the at least one multi-mode element controller may also generate output signals for the at least one controllable phased array antenna element based upon the beam control signals from the central controller.