A concept for MIMO antenna array in a laptop computer, integrated with a display ground plane, is proposed. The proposed MIMO antenna array consists of two same WLAN antennas. Both the two WLAN antennas occupy a small size of 80 mm × 2 mm and are etched on the display ground plane with a distance of 5 mm from the top edge. There is a spacing of 80 mm between the two WLAN antennas to enhance isolation between the antennas. The proposed WLAN MIMO antenna array has simulated isolation of better than 42 dB in all WLAN operation (2.4/5.2/5.8 GHz bands) in this study. Additionally, the antenna efficiencies are better than about 80 and 78%, respectively, in the 2.4 and 5.2/5.8 GHz bands for the two antennas. The proposed MIMO antenna array is characterized by its seamless integration with the display ground plane, good isolation and excellent antenna efficiency.