An antenna system includes an antenna body having one or more connection points between the antenna body and a ground; a tunable component having a changeable operating parameter that is a capacitance or a inductance, wherein the antenna body is connected to the tunable component through a first connection point; and a first filter, wherein the first filter are connected to the antenna body; wherein the first filter is connected in parallel with the tunable component, wherein a first end of the first filter is connected to the antenna body through the first connection point, and a second end of the first filter is connected to the ground, and wherein the first filter presents a high impedance characteristic in a low frequency band, and presents a low impedance characteristic in a high frequency band.