A tunable antenna device having proximity detection

The invention provides an adjustable antenna device capable of detecting an approaching object. The adjustable antenna device capable of detecting the approaching object includes a first radiator, a ground portion, a second radiator, a proximity sensing chip, and a variable capacitor. The first radiator comprises a signal feeding point, so that an antenna signal is fed to the first radiator. The variable capacitor and the proximity sensing chip are arranged in the range of the first radiator, the ground portion, and the second radiator, and used to adjust the frequency of the antenna. In addition, a plurality of switches and capacitor adjustment blocks can be used instead of the variable capacitor. The capacitance adjustment blocks and the ground portion are arranged on different surfacesof a circuit board. The areas of the capacitor adjustment blocks are different from each other. Switches are used to selectively electrically connect one of the capacitance adjustment blocks and the second radiator, so as to