Abstract : The WiBro was adopted to the 3G international standard. By the change of specification form Wave 1 to Wave 2, MIMO technology is applied in order to increase the speed of downlink. By MIMO the RF part of WiBro base station is increased to 2 Tx paths. Therefore, the size of RF part is bigger and material cost is increased. For reducing these demerits, the RF part which is consisted of PA, LNA, and TDD switch is designed to one complex RF unit. Also, the experimental results of the RF unit have been discussed. Since the complex RF unit is more compact than the RF part of WSave 1 base station, it can be used as the RF part of Wave 2 base station with 2T/2R MIMO.