Pattern optimization is proposed for a beam-steerable dielectric resonator antenna (DRA) array fed by a two-stage feeding network based on varactor-based phase shifter pairs. Based on the calibration on the feeding network and the actual measured radiation patterns, unexpected distortion of patterns such as inaccurate beam direction caused by material and fabrication tolerance can be corrected. According to the observed distortions, correcting phase differences on the phase shifter pair can be identified. To verify this process, two scenarios of accurate beam direction correction are illustrated in this paper. The optimized patterns obtained in measurement show that the proposed pattern optimization is efficient and practical for the beam-steerable array fed by varactor-based phase shifters.