Antenna structure and bluetooth antenna

An antenna structure, comprising:

• a main radiation element, having a feeding point;
• a first ground element, comprising a first connection segment, a first protruding segment, and a second protruding segment;
• a second ground element, comprising a second connection segment, a third protruding segment, and a fourth protruding segment, wherein the main radiation element is coupled to the second ground element, and wherein the main radiation element is surrounded by the first ground element and the second ground element;
• a first capacitor, coupled between the first protruding segment and the third protruding segment;
• a second capacitor, coupled between the second protruding segment and the fourth protruding segment;
• a metal cavity, coupled to the first connection segment and the second connection segment;
• and
• a carrier element, disposed in the metal cavity, wherein the carrier element is configured to carry the main radiation element, the first protruding segment, the second protruding segment, the third protruding segment, the fourth protruding segment, the first capacitor, and the second capacitor;
• wherein the main radiation element comprises a first portion, a second portion, and a third portion, wherein the first portion is coupled to the feeding point, the second portion is coupled between the first portion and the third portion, and the third portion is coupled to the second connection segment and the fourth protruding segment.