Patent ID: 8854268

Claim:
A tunable antenna comprising: a ground element for providing grounding; a signal feed-in terminal; a radiation unit electrically connected to the signal feed-in terminal and including a long side extended from the signal feed-in terminal along a first direction, a short side extended from the signal feed-in terminal along a second direction, and a branch electrically connected between the signal feed-in terminal and the ground element; a coupling unit for coupling to the long side, comprising: a horizontal side substantially parallel to the long side; and a plurality of vertical sides electrically connected and substantially perpendicular to the horizontal side; and a switch unit for connecting or disconnecting the coupling unit to or from the ground element to change a coupling relationship between the coupling unit and the long side, such that the tunable antenna respectively operates in a first frequency band and a second frequency band; wherein the switch unit connects one of the plurality of vertical sides to the ground element to generate different coupling relationships between the coupling unit and the long side.