Antenna structure

An antenna structure, comprising:

• a first radiation element, having a feeding point;
• a second radiation element, wherein the first radiation element is coupled through the second radiation element to a ground voltage;
• a third radiation element, coupled to the first radiation element;
• a fourth radiation element, coupled to the first radiation element, wherein the third radiation element and the fourth radiation element substantially extend in opposite directions;
• a fifth radiation element;
• a tuning circuit, wherein the fifth radiation element is coupled through the tuning circuit to the ground voltage;
• a first floating metal element, disposed between the second radiation element and the third radiation element;
• a second floating metal element, disposed between the third radiation element and the fifth radiation element;
• and
• a nonconductive support element, wherein the first radiation element, the second radiation element, the third radiation element, the fourth radiation element, the fifth radiation element, and the tuning circuit are disposed on the nonconductive support element.