A communication device, comprising: a front housing; a display module; a display panel installed between the display module and the front housing; a back cover made of metal or plastic; a main body located between the front housing and the back cover, the main body being made of a non-conductive material; a printed circuit board installed on the main body and comprises a signal feed point and a ground point; an antenna installed on the main body, the antenna comprising a first metal part, a second metal part and a third metal part extended and connected between the first metal part and the second metal part, wherein the first metal part of the antenna is coupled to the signal feed point, and the second metal part of the antenna is coupled to the ground point; and a conductor, wherein a coupling gap is defined between the conductor and the antenna, at least one part of the conductor corresponds to the display panel; characterized in that the conductor comprises a first conductive part, a second conductive part coupled to the first conductive part, and a slit formed on the second conductive part for the conductor to properly match with the antenna to adjust the bandwidth; the conductor guides an electromagnetic radiation energy to the display panel; when the communication device is turned on, the electromagnetic radiation energy can be transmitted to the antenna and the back cover via the signal feed point and the ground point of the printed circuit board such that the back cover can be utilized as a radiating surface, for transmitting and receiving radio signals of the communication device; and the electromagnetic radiation energy of the antenna is guided to the display panel through the conductor via the coupling gap that couples the electromagnetic radiation energy to the conductor. a front housing; a display module; a display panel installed between the display module and the front housing; a back cover made of metal or plastic; a main body located between the front housing and the back cover, the main body being made of a non-conductive material; a printed circuit board installed on the main body and comprises a signal feed point and a ground point; an antenna installed on the main body, the antenna comprising a first metal part, a second metal part and a third metal part extended and connected between the first metal part and the second metal part, wherein the first metal part of the antenna is coupled to the signal feed point, and the second metal part of the antenna is coupled to the ground point; and a conductor, wherein a coupling gap is defined between the conductor and the antenna, at least one part of the conductor corresponds to the display panel; characterized in that the conductor comprises a first conductive part, a second conductive part coupled to the first conductive part, and a slit formed on the second conductive part for the conductor to properly match with the antenna to adjust the bandwidth; the conductor guides an electromagnetic radiation energy to the display panel; when the communication device is turned on, the electromagnetic radiation energy can be transmitted to the antenna and the back cover via the signal feed point and the ground point of the printed circuit board such that the back cover can be utilized as a radiating surface, for transmitting and receiving radio signals of the communication device; and the electromagnetic radiation energy of the antenna is guided to the display panel through the conductor via the coupling gap that couples the electromagnetic radiation energy to the conductor.