Abstract: An antenna device includes a housing having a peripheral depression located around an orifice and formed between a peripheral rib and an inner peripheral surface of the housing, an antenna member having two shafts extended from a casing, a gear disposed on each of the shafts and movably engaged in the peripheral depression defined between the peripheral rib and the inner peripheral surface of the housing for guiding the casing of the antenna member to rotate relative the housing. A cap may rotatably secure the casing to the housing, to allow the casing to be rotated relative to the housing with the shafts or by a movement of the gears of the shafts in the peripheral depression of the housing.