An electronically tunable reflectarray of aperture coupled square dielectric resonator antenna (DRA) elements is designed with a 230 mm × 230 mm size. The DRA phase is controlled via a capacitive varactor. The results show that the beam scanning within ± 60° range can be realized. The reflectarray is center-fed by a linearly polarized pyramidal horn antenna. At 10.6 GHz, the antenna provides a 3-dB beamwidth of 6 degrees with a gain of 25.5 dB. The antenna bandwidth within 1.5 dB gain variation is found to be 9% with stable radiation patterns.