An Ultra Wideband (UWB) coupling mechanism and method for a mobile terminal are provided. The UWB coupling mechanism includes a main unit having a first short range communication unit, a memory for storing data received or to be transmitted through the first short range communication unit, a radio frequency unit for establishing a radio channel with a mobile communication system, and a control unit for controlling communication between the first short range communication unit, memory, and radio frequency unit; and a sub-unit having a second short range communication unit for establishing a wireless channel to the first short range communication unit, and a function unit for executing various functions of the mobile terminal.