This document describes the design of a compact multiple-input multiple-output (MIMO) antenna array for wireless local area network (WLAN) applications. It presents a pattern diversity approach using printed Yagi-Uda antennas arranged in a triangular configuration to achieve orthogonal radiation patterns and reduce mutual coupling. Each Yagi-Uda antenna is designed on an FR4 substrate with parasitic elements to direct the beam. The MIMO array exhibits mutual coupling below -20 dB and bandwidth from 4.8-6.2 GHz covering the upper WLAN band. Simulation results show the array provides good impedance matching, gain of 2.29 dBi, and directivity of 2.97 dBi at 5.69 GHz operating frequency