Method and apparatus for wired and wireless communication

1. A terminal device comprising:

an antenna element mounted on a casing of the terminal device to transmit/receive electromagnetic waves;

an interface component configured to couple an external device with the terminal device for a wired transmission, the interface component comprising a metal shell configured to have a fixed potential state to shield the wired transmission from noise when the interface component is active for the wired transmission, and to have a floating state to avoid affecting the antenna element for transmitting/receiving electromagnetic waves when the interface component is idle;

a switch configured to connect the metal shell to a wound portion of the terminal device when the interface component is active, and disconnect the metal shell from the ground portion of the terminal device to float the metal shell when the interface component is idle; and

a detecting and controlling circuit configured to detect a state of the interface component and control the switch based on the state of the interface component.

2. The terminal device of claim 1 , comprising:

a plurality of switches that are distributed and connected with the metal shell in parallel to connect the metal shell to the ground portion of the terminal device when the interface component is active, and disconnect the metal shell from the ground portion of the terminal device to float the metal shell when the interface component is idle.

3. The terminal device of claim 1 , wherein the interface component is a USB receptacle for coupling a USB plug in connection with the external device.

4. The terminal device of claim 1 , wherein the interface component is a headphone socket for coupling an audio plug.

5. The terminal device of claim 1 , wherein the interface component is surrounded with isolation by a metal panel that forms the antenna element.

6. A method for use in a terminal device, comprising:

switching a metal shell for an interface component of the terminal device to a fixed potential to shield a wired transmission from noise when the interface component is active to conduct the wired transmission between the terminal device and an external device;

switching the metal shell away from the fixed potential to float the metal shell when the interface component is idle to avoid affecting an antenna element of the terminal device for transmitting/receiving electromagnetic waves;

switching the metal shell to a ground portion of the terminal device when the interface component is active;

switching the metal shell away from the ground portion of the terminal device to float the metal shell when the interface component is idle;

detecting a state of the interface component; and

switching the metal shell based on the state of the interface component.

7. The method of claim 6 , comprising:

controlling a plurality of switches that are distributed and connected with the metal shell in parallel to connect the metal shell to the ground portion of the terminal device or disconnect the metal shell from the ground portion of the terminal device.

8. The method of claim 6 , wherein the interface component is a USB receptacle for coupling a USB plug in connection with the external device.

9. The method of claim 6 , wherein the interface components is a headphone socket for coupling an audio plug.

10. The method of claim 6 , wherein the interface component is surrounded with isolation by a metal panel that forms the antenna element.

11. An electronic device comprising:

an antenna element configured to transmit/receive electromagnetic waves for wireless communication;

an interface component configured to couple an external device with the electronic device for wired communication, the interface component comprising a metal shell configured to have a fixed potential to shield the wired communication from noise when the interface component is active for the wired communication, and to have a floating state to avoid affecting the antenna element for the wireless communication when the interface component is idle;

one or more switches configured to connect the metal shell to a ground portion of the electronic device when the interface component is active, and disconnect the metal shell from the ground portion of the electronic device to float the metal shell when the interface component is idle; and

a detecting and controlling circuit configured to detect a state of the interface component and control the one or more switches based on the state of the interface component.

12. The electronic device of claim 11 , wherein the interface component is a USB receptacle for coupling a USB plug in connection with the external device.

13. The electronic device of claim 11 , wherein the interface component is a headphone socket for coupling an audio plug.

14. The electronic device of claim 11 , wherein the interface component is surrounded with isolation by a metal panel that forms the antenna element.