Abstract: A coupling device that is used to test power or field effects of an antenna built into an antenna device is proposed. The antenna device is plate-shaped. The coupling device has a housing, an isolation material, and a connector. The housing has a socket at one side. The socket is capable of receiving the antenna device. The isolation material is disposed inside the socket of the housing. The isolation material has a chamber and a metal plate attached to an inner wall of the chamber. The connector is disposed at another side of the housing. The connector is connected to the metal plate and the metal plate is connected to the housing.