A card device includes one or more antenna devices printed on a board member and each having a T-shaped structure formed by two segments, for sending or receiving wireless signals or for wireless transmission purposes, and for allowing the antenna device to be easily printed and applied onto the board member of the card device without additional securing or welding or assembling processes. Each of the antenna devices includes a conductor printed around the T-shaped antenna device to form a T-shaped hollow space in the antenna device.