A four-sector switchable WiMAX antenna, for indoor use in the 4.9 -5.0 GHz frequency bands, is presented. The prototype antenna is designed to provide a higher gain in a specified sector region. Furthermore, the radiation beam is electronically steerable to provide space diversity in four different sectors. Each sector of this antenna includes an array of two rectangular microstrip patches. The air gap between the bottom substrate of microstrip patches and the ground plane is increased to 3 mm, which can aid in accomplishing a high-gain and wideband design goal. A solid-state microwave switch is used to select one of the four sectors.