An antenna structure is electronically connected to a connector of a wireless communication device. The connector includes a power terminal and a ground terminal. The antenna structure includes a main antenna, a secondary antenna, and two posts. The main antenna includes a feed portion and a ground portion. The secondary antenna extends from the main antenna. One post electronically connects the power terminal of the connector to the feed portion, and the other post electronically connects the ground terminal of the connector to the ground portion. A wireless communication device employing the antenna structure is also described.