A communication device includes an RF (Radio Frequency) module, an antenna structure, a first switch element, a second switch element, a plurality of first impedance elements, and a plurality of second impedance elements. The antenna structure is coupled to the RF module. The antenna structure includes a first radiation element and a second radiation element. The first switch element is coupled to the first radiation element. The first switch element is switchable between the first impedance elements. The second switch element is coupled to the second radiation element. The second switch element is switchable between the second impedance elements.