Antenna System

An antenna system, comprising:

• a system ground unit;
• a metal back cover electrically connected with the system ground unit;
• a frame which is provided surrounding a periphery of the metal back cover and serves as an antenna radiator;
• and
• a grounding circuit, a feeding circuit and a tuning switch respectively connected with the antenna radiator and the system ground unit,
• wherein the antenna radiator comprises a main radiator and an auxiliary radiator provided at two opposite sides of the metal back cover;
• the main radiator comprises a first main radiator which forms, together with the metal back cover, a first main gap and a first main antenna, a second main radiator which extends from the first main radiator and forms, together with the metal back cover, a second main gap and a second main antenna, and a first fracture which separates the first main radiator into two parts;
• the auxiliary radiator comprises a first auxiliary radiator which forms, together with the metal back cover, a first auxiliary gap and a first auxiliary antenna, a second auxiliary radiator which extends from the first auxiliary radiator and forms, together with the metal back cover, a second auxiliary gap and a second auxiliary antenna, and a second fracture which separates the first auxiliary radiator into two parts.