An antenna device with a surface antenna pattern is formed either on an internal surface or on the external surface of a casing of an electronic device by film coating technology. The surface antenna pattern is either directly connected to a signal feeding line or connected to a signal feeding line through a signal guiding passage. In an embodiment, a recess is pre-formed on the external surface of the casing and then a surface antenna pattern is coated to the recess. The antenna device may further comprise an antenna coupling element arranged at the internal surface of the casing, in opposite to the surface antenna pattern. The antenna coupling element is inductively coupled with the surface antenna pattern for transceiving the signals to the electronic device.