An antenna structure includes a feed end plate, a ground end plate, a first radiator, a second radiator, and a metallic plate. The first radiator is coupled to the feed end plate. The second radiator is coupled to the ground end plate. The metallic plate is spaced from the first radiator and is couple the second radiator. The metallic plate includes a main sheet and at least one side sheet connected to the main sheet, a gap is defined between the main sheet and the first radiator, and the second radiator is coupled to the at least one side sheet.