An antenna apparatus having an antenna. The antenna comprises a first radiator section and a second radiator section coupled to each other, and a third radiator section, a fourth radiator section, and a fifth radiator section that are distributed on a same side of the first and second radiator sections, wherein the third radiator section is coupled to a junction of the first and second radiator sections and is grounded, and the fourth and fifth radiator sections are separately disposed on two sides of the third radiator section, wherein the fourth radiator section is grounded by a first switch, and the fifth radiator section is grounded by a second switch.