Mobile device

A mobile device, comprising:

• an antenna structure, comprising:
• a main radiation element, having a feeding point;
• a first parasitic element, having a first grounding point, wherein the first parasitic element is adjacent to the main radiation element, and wherein the first grounding point is adjacent to the feeding point;
• and
• a second parasitic element, having a second grounding point, wherein the second parasitic element is adjacent to a first end of the main radiation element;
• wherein the antenna structure operates in a low-frequency band and a high-frequency band, wherein the low-frequency band is from 2400 MHz to 2500 MHz, and wherein the high-frequency band is from 5150 MHz to 5850 MHz;
• wherein the antenna structure further comprises a third parasitic element, wherein the third parasitic element substantially has an L-shape, wherein a first end of the third parasitic element is a third grounding point, and wherein a second end of the third parasitic element is open and adjacent to a median portion of the main radiation element;
• wherein a length of the third parasitic element is about 0.25 wavelength of the high-frequency band;
• wherein the second parasitic element substantially had an N-shape;
• and
• wherein the antenna structure further comprises as auxiliary radiation element, wherein the auxiliary radiation element substantially has a straight-line shape, wherein a first end of the auxiliary radiation element is coupled to the feeding point, and wherein a second end of the auxiliary element is open.